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MXene has excellent capacitive properties as a two-dimensional material, but its cycling stability is poor. β-PbO 2 is one of the common crystalline forms of lead dioxide, and it has excellent electrochemical properties and cyclic stability and has potential as a capacitor electrode material. However, the capacitive performance of β-PbO 2 as a capacitor electrode material is not ideal. Therefore, CF/MXene/β-PbO 2 (CMP) composites were prepared in this study by combining β-PbO 2 with CF/MXene (CM) using a constant current electrodeposition method, and their electrochemical energy storage properties were investigated. The ordered structure of interwoven CF is used to fix MXene, which has metallic properties and large layer spacing, as the matrix material. This utilization enables faster ion transport and electron storage. The electrochemical advantages of β-PbO 2 and CM can be unified by the synergistic effect of the composites, which results in a high specific capacity (399.42 F g−1) of the CMP electrode at 0.2 A g−1. In addition, the CM//CMP asymmetric supercapacitor constructed in 1 M Na 2 SO 4 solution has a wide potential window of 2.0 V and a high specific capacitance of 193.8C g−1, and the capacity remains 54.3% of the initial value after 5000 cycles at a charge/discharge rate of 40 mA g−1. This work provides important research ideas and clues for the application of β-PbO 2 composite electrode materials in supercapacitors. [ABSTRACT FROM AUTHOR]

Mineralization of benzene, toluene, and xylene (BTX) with high efficiency at room temperature is still a challenge for the purification of indoor air. In this work, a foam Ti/Sb-SnO 2 /β-PbO 2 anode catalyst was prepared for electrocatalytically oxidizing gaseous toluene in an all-solid cell at ambient temperature. The complex Ti/Sb-SnO 2 /β-PbO 2 anode, which was prepared by sequentially deposing Sb-SnO 2 and β-PbO 2 on a foam Ti substrate, shows high electrocatalytic oxidation efficiency of toluene (80%) at 7 hr of reaction and high CO 2 selectivity (94.9%) under an optimized condition, i.e., a cell voltage of 2.0 V, relative humidity of 60% and a flow rate of 100 mL/min. The better catalytic performance can be ascribed to the high production rate of ⋅OH radicals from discharging adsorbed water and the inhibition of oxygen evolution on the surface of foam Ti/Sb-SnO 2 /β-PbO 2 anode when compared with the foam Ti/Sb-SnO 2 anode. Our results demonstrate that prepared complex electrodes can be potentially used for electrocatalytic removal of gaseous toluene at room temperature with a good performance. [Display omitted] [ABSTRACT FROM AUTHOR]

The assessments of a novel electrochemical advanced oxidation process are presented, where PbO 2 anode and H 2 O 2 electrosynthesis cathode are simultaneously used in one system. The anode is β-PbO 2 coated on a titanium substrate. The cathode is fabricated by rolling the activated Vulcan XC-72R carbon catalyst and PTFE binder on the titanium current collector as the catalyst layer and water-repellent layer, according to different carbon/PTFE ratios. Different electrolysers are used to evaluate the synergistic contributions of the PbO 2 anode and H 2 O 2 generated cathode on the pollutant degradation process. The contributions of both direct anodic oxidation and indirect oxidation can be observed. The synergy of the PbO 2 anode and H 2 O 2 on-site generated cathode can significantly enhance the oxidation ability and COD removal. Almost all COD in the real pesticide wastewater and dye wastewater can be removed using a PbO 2 -H 2 O 2 batch electrolyser, which is run at a cell voltage of 3.0 V and at room temperature. The reaction mechanisms in both chloride-containing and sulfate-containing wastewater are discussed particularly. [ABSTRACT FROM AUTHOR]

In this study, we fabricated a blue-TiO 2 /PbO 2 -carbon nanotube (CNT) electrode in which blue TiO 2 nanotube arrays (blue-TNA) served as the substrate for PbO 2 -CNT eletrodeposition. Scanning electron microscope (SEM) showed compact surface structure of the electrode. The β-PbO 2 crystal structure was detected by X-ray diffraction (XRD). The distribution of Pb, O, C, and Na elements on the electrode surface have been confirmed by X-ray photoelectron spectroscopy (XPS). Blue-TiO 2 /PbO 2 -CNT electrode had higher response current (213.12 mA), larger active surface area and lower charge transfer resistance (2.22 Ω/cm2) than conventional TiO 2 /PbO 2 -CNT electrode. The influences of current density, initial phenol concentration, initial solution pH, and Na 2 SO 4 concentration on the electrochemical oxidation of phenol have been analyzed. The results showed that the 100 mg/L phenol could be destroyed completely after 210 min, and chemical oxygen demand (COD) removal rate was 89.3% within 240 min. Additionally, the electrode showed long actual lifetime (5468.80 hr) and low energy consumption (0.08 kWh/gCOD). A phenol degradation mechanism was proposed by analyzing the intermediate products with high-performance liquid chromatography-mass spectrometry (HPLC-MS). Importantly, the blue-TiO 2 /PbO 2 -CNT electrode exhibited superior stability and high degradation efficiency after 15 times reuse, demonstrating its promising application potential on phenol-containing wastewater treatment. [Display omitted] [ABSTRACT FROM AUTHOR]

• A PbO x @C/GF electrode was manufactured to remove dye from water. • Doping with PbO improved the adsorption of oxygen and the degradation of the dye. • Active oxygen on the surface of the electrode promoted the degradation of the dye in the water. • The PbO x @C/GF showed strong electrocatalytic performance and stability. • The PbO x @C/GF system reached 100 % COD removal with 24.44 kW·h/kg-COD for industrial wastewater. Electro-assisted catalytic wet air oxidation (ECWAO) is an environmentally-friendly pollutant removal process with energy-saving and mild reaction properties. However, it requires an electrode with high catalytic capacity and stability, and the catalytic mechanism behind the process still needs to be further clarified. Herein, we report a graphite felt (GF)-supported PbO x catalyst which can chemically adsorb oxygen and activate it into free radicals by an anodic electric field to promote wet air oxidation. XRD, SEM, EDS, XPS, BET and TG measurements indicated that PbO and PbO 2 were successfully doped and loaded onto the GF, increasing the specific surface area and number of active sites. The best RhB degradation efficiencies achieved were 91.26 % over 15 min and 96.68 % over 90 min. The PbO x @C/GF maintained good catalytic performance over eight cycles in the pH range of 3–11 with negligible metal leaching. The RhB degradation pathway of RhB was analyzed through GC–MS results. A free radical quenching experiment, a contrast experiment, and an electrochemical test revealed the process of oxygen being adsorbed by Pb(II) and activated to degrade organic matter was revealed. Five kinds of dyes were degraded by the electrode via the ECWAO process, and the degradation rate reached over 93.7 % within 90 min. The degradation specific energy consumption (SEC) of probe pollutant RhB is 48.70 kW·h/kg-COD. The industrial practical dye wastewater COD removal rate was close to 100 %, and the SEC was 24.44 kW·h/kg-COD. Therefore, it can be concluded that a graphite felt (GF)-supported PbO x catalyst can act as an anode for ECWAO to chemically adsorb oxygen and activate it into free radicals using an anodic electric field to promote wet air oxidation. [ABSTRACT FROM AUTHOR]

This work presents the mathematical modeling, simulation, and experimental validation of a paired metal ions recovery process in a rotating cylinder electrode (RCE) electrochemical reactor in a continuous mode of operation. The process involves the recovery of copper, Cu(II), and silver, Ag(I), ions cathodically with the simultaneous recovery of lead, Pb(II), ions anodically. The experimental process was implemented in a traditional RCE electrochemical reactor, with a stainless-steel cylinder working as a cathode and six-dimensional stable plate anodes (DSA) concentric to the cathode. The experimental scheme consisted of a central composite design (CCD) with three response variables, the Cu(II), Ag(I), and Pb(II) conversion as a function of the rotating speed (rpm), current density (A m−2), and flow rate (cm3 min−1). Second-order empirical polynomials were fitted to the Cu(II) and Ag(I) conversion experimental data, while for Pb(II) conversion, a first-order polynomial was fitted. The hydrodynamics and tertiary current distribution phenomena were modeled and simulated numerically using the commercial computational fluid dynamics (CFD) software COMSOL Multiphysics. The CFD models obtained were validated with the experimental information from the experimental design. Low deviation values of the theoretical approximation to the experimental values were obtained. Also, empirical models were developed from the experimental design, which are useful for predicting the response variables in the space design, while the validated CFD models can predict the RCE electrochemical reactor behavior at any operation condition. [ABSTRACT FROM AUTHOR]

Water scarcity is becoming a serious threat for the implementation of energy storage devices based on hydrogen in the inland of dry regions, because of the difficulties in finding appropriate sources of water and the important environmental problem associated with the discharge of rejection saline streams produced during the purification of water. This becomes an opportunity for chloralkaline technology in which the quality of water used is lower than the required in other hydrogen production technologies. This work compares the performance of chloralkaline electrolyzers fed with different solutions of NaCl (from brackish water to brines) with that obtained feeding two natural water samples (seawater and porewater) and three processed waters (rejections streams of the electrodialysis, reverse osmosis of the porewater and a real rejection of the reverse osmosis of a vineyard). All tests were made with a lab-scale 3-D printed cell where, in addition, the performance of Ti/RuO 2 and Pb/PbO 2 anodes were compared, being always better the results obtained in the tests made with the Ti/RuO 2 electrode. Results obtained indicate that efficiencies reached using these alternative sources are lower than those which can be reached using synthetic brines that, in turn, were very near to the standards reached in the chloralkaline industry. In the case of hydrogen production, the maximum values were obtained for seawater, reaching efficiencies proximate to 8.0 mg H 2 (Wh)−1. Rejection streams of desalination processes were found to be less efficient, attaining values in the range 2 and 4 mg H 2 (Wh)−1. Regarding the production of chlorine and caustic soda, better performances were reached again with seawater (161.7 mg Cl 2 (Wh)−1 and 0.092 mg OH− (Wh)−1) and with the rejection of the electrodialysis, which also reached sound values of 90.4 mg Cl 2 (Wh)−1 and 0.107 mg OH− (Wh)−1. Results obtained are promising and indicate a path that must be further worked for the implementation of a greener water management strategy in the hydrogen -based energy storage technology. • Different types of water can be successfully used to fed chloralkaline electrolyzer. • Important influence of the composition & concentration and necessity of concentration. • Performance of electrolyzers with Ti/RuO 2 electrodes better than with Pb/PbO 2. • Electrolysis of seawater reaches 8 mg H 2 (Wh)−1,161.7 mg Cl 2 (Wh)−1 and 0.092 mg OH− (Wh)−1. • Among the concentration technologies, better results are reached by electrodialysis. • Necessity to improve performance of membranes against crossover of chlorine. [ABSTRACT FROM AUTHOR]

[Display omitted] • Ti/SnO 2 -Sb 2 O 4 -La/β-PbO 2 electrode was prepared and used to degrade dye wastewater. • β-PbO 2 coating greatly improved the conductivity of the electrode. • Ti/SnO 2 -Sb 2 O 4 -La/β-PbO 2 electrode can completely degrade different dye wastewater within 30 mins. • The practical life of the electrode is as long as 3208 hrs. In this work, Ti/SnO 2 -Sb 2 O 4 -La/β-PbO 2 electrode was successfully prepared by electrodeposition method. The surface morphology, crystal structure, elemental states and electrochemical characteristics of the electrode were examined by SEM, XRD, XPS, CV, and LSV. The results demonstrated that the conductivity, specific surface area, electrochemical oxidation performance and stability of the β-PbO 2 coated electrode with SnO 2 -Sb 2 O 4 -La as the intermediate layer were greatly improved. Under the conditions of initial rhodamine B (RhB) concentration of 20 mg/L, initial pH of 3.0, electrolyte concentration of 0.1 M, and current density of 30 mA cm−2, the removal rates of color and TOC reached 100 % and 83.64 % after 20 mins and 30 mins, respectively. The electrode can also completely degrade methylene blue and methyl orange wastewater after 30 mins under the same conditions. The accelerated lifetime of the electrode reached 175 mins (1000 mA cm−2, 1 M H 2 SO 4), and the actual lifetime was up to 3208 hrs. Based on the results of free radical quenching experiment and GC–MS detection, RhB degradation pathway was proposed: the aniline-based conjugated system of RhB molecule was attacked by the combined action of free radicals (indirect oxidation) and electrocatalysis (direct oxidation), which decomposed macromolecules into small molecules and ultimately mineralized them into CO 2 and H 2 O. This work is expected to provide a fresh research concept for preparing DSA electrodes with excellent catalytic performance and high stability. [ABSTRACT FROM AUTHOR]

Glasses with varying compositions were prepared using the melt-quenching process within the 40B 2 O 3 –20PbO-xZnO-(40-x)CaO system, where x = 20, 25, 30 and 35 mol%. ZnO's influence on the prepared glasses' radiation shielding properties was studied in the 0.015–15 MeV energy range. The results demonstrated that ZnO has a significant shielding effect at low energies, where there is an increased in the linear attenuation coefficient from 279.96 to 319.17 cm−1 at 0.015 MeV due to the 20-to-35 mol% increase in ZnO. The values of the mean free path (MFP) for the prepared glasses are very small when the energy is less than 0.1 MeV, in the order of 0.013–0.015 cm at 0.03 MeV, 0.051–0.055 cm at 0.05 MeV and 3.051–3.248 cm at 1 MeV, which revealed an enhanced attenuation efficiency with increasing ZnO content. According to the MFP results, the Zn35Ca5 sample (which contains 35 mol% ZnO) offers the best shielding performance. The half value layer (HVL) was also evaluated, and we found that the HVL is in order of 1.5 cm at 0.6 MeV, and in order of 3 cm at 2 MeV, while at 15 MeV, the HVL is 4.30 cm for Zn20Ca20 and 3.74 cm for Zn35Ca5. • We prepared B 2 O 3 –PbO–ZnO–CaO glass systems for radiation shielding applications. • ZnO has a significant shielding effect at low energies. • The LAC changed from 279.96 to 319.17 cm−1 at 0.015 MeV due to the change in ZnO. • The HVL is in order of 1.5 cm at 0.6 MeV, and in order of 3 cm at 2 MeV. [ABSTRACT FROM AUTHOR]

In this study, a zeolite-doped PbO 2 (Zeo-PbO 2) anode was fabricated via electrodeposition technology for electrochemical oxidation of m -nitrophenol (m -NP). The results of characterization revealed that doping zeolite efficiently promoted the oxygen evolution potential and active sites of PbO 2 anode, thereby higher performance to generate •OH radical and degrade the m -NP. The •OH radical was confirmed to be the primary contributor to the electrochemical oxidation of m -NP by scavenging tests. Thus, the effect mechanism of current density, supporting electrolyte, and initial pH on the removal of m -NP in the electrochemical oxidation process was explored by the generation of •OH radicals at different conditions. Based on the vulnerable sites of m -NP to the attack of •OH radical supposed by the theoretical calculation and degradation intermediates identified by GC-MS and IC, the degradation pathways of m -NP in the electrochemical oxidation process were speculated. Besides, the good recyclability and stability of Zeo-PbO 2 anode were exhibited in consecutive m -NP degradation, •OH generation experiments, and accelerated life tests. [Display omitted] • Doping Zeolite boosted the electroatalytic activity of PbO 2 anode. • Current, pH and supporting electrolyte influenced the yield of •OH. • Theoretical calculation and experimental analyses revealed the degradation pathway of m-NP. • The Zeo-PbO 2 anode offered higher stability compared to pure PbO 2 anode. [ABSTRACT FROM AUTHOR]

Coking reverse osmosis concentrated water contains refractory organic pollutants. If not treated, it will generate hazardous solid waste that cannot be utilized in the subsequent evaporation and crystallization process. In order to effectively remove organic substances from coking reverse osmosis concentrated water, Ti/PbO 2 electrode, Ti/Ce,Nd-PbO 2 electrode, and Ti/P(ANI-co-Py)/Ce,Nd-PbO 2 electrode were prepared. The electrodes were characterized by scanning electron microscopy, X-ray diffraction spectroscopy, and X-ray photoelectron spectroscopy, revealing that the average crystal grain size of lead dioxide on the surface of the Ti/P(ANI-co-Py)/Ce,Nd-PbO 2 electrode is 29.58 nm. The electrochemical performance of the electrodes was tested using cyclic voltammetry and electrochemical impedance spectroscopy, which showed oxidation peaks at 1.37 V, 1.81 V, and 2.1 V for the Ti/P(ANI-co-Py)/Ce,Nd-PbO 2 electrode, with a charge transfer resistance of 56.34 Ω. Accelerated life test indicated that the Ti/P(ANI-co-Py)/Ce,Nd-PbO 2 electrode has an accelerated lifespan of 1050 min. The effects of interelectrode distance, pH value, current density, and other factors on the electrocatalytic oxidation of 3,5-di-tert-butylphenol by the Ti/P(ANI-co-Py)/Ce,Nd-PbO 2 electrode were investigated, achieving a removal efficiency of 98.67 % under optimal conditions. Performance analysis of the Ti/P(ANI-co-Py)/Ce,Nd-PbO 2 electrode demonstrated good stability. Treatment of actual coking reverse osmosis concentrated water using the Ti/P(ANI-co-Py)/Ce,Nd-PbO 2 electrode resulted in removal efficiencies of 87.76 %, 47.92 %, and 77.42 % for COD, TOC, and UV 254 , respectively. The current efficiency and energy consumption of electrocatalytic degradation of coking reverse osmosis concentrated water were 9.38 % and 0.15 kWh/g COD. This study provides a better treatment solution for the degradation of organic matter in coking reverse osmosis concentrated water. [Display omitted] • The intermediate layer P(ANI-co-Py) has improved the lifespan and the stability of the lead dioxide electrode. • Doping Ce and Nd into the PbO 2 layer improves the electrocatalytic performance of the lead dioxide electrode. • The conditions for degradation of 3,5-di-tert-butylphenol were optimized on the Ti/P(ANI-co-Py)/Ce,Nd-PbO 2 electrode. • The mechanism of 3,5-di-tert-butylphenol degradation on the Ti/P(ANI-co-Py)/Ce,Nd-PbO 2 electrode was investigated. • An analysis was conducted on the electrode's reusability and practical application potential. [ABSTRACT FROM AUTHOR]

To lengthen the lifetime and extend the potential commercial applications of lead dioxide electrode. Herein, PbO 2 –TiO 2 heterostructured electrodes were fabricated via direct current electrodeposition and the surface of the electrode was characterized by electron microscopy (EDS), X-ray diffraction (XRD) and scanning electron microscopy (SEM). The PbO 2 –TiO 2 heterostructure electrode could produce an obvious photocurrent under UV irradiation, indicating a photoelectrocatalytic reaction. The PbO 2 –TiO 2 heterostructured electrode was examined using density functional theory calculations(DFT). Work function(WF) confirmed that the applied electric field is conducive to the movement of photoelectrons, which promotes the photoelectrocatalysis effect. The nudged elastic band(NEB) results showed that the PbO 2 –TiO 2 heterostructure electrode can promote the formation of •OH by reducing the activation barrier. The PbO 2 –TiO 2 electrode was used as an anode to treat P-aminophenol (PAP) wastewater simulated wastewater and real PAP wastewater via photoelectrocatalytic degradation. The PbO 2 –TiO 2 electrode effectively removes chemical oxygen demand (COD) from actual wastewater was 54.93 %,The after-treated Pb2+ concentration (0.037 mg·L−1) was lower than China's wastewater discharge standard (1 mg·L−1). Finally, the degradation pathway of PAP was determined based on the intermediates detected using gas chromatography–mass spectrometry and the reactive sites of PAP were predicted using the Fukui function.These results suggest that the photoelectrocatalysis degradation of PAP using electrodes is feasible. • PbO 2 –TiO 2 electrode can improve the photoelectrocatalysis performance. • The applied electric field is conducive to the movement of photoelectrons. • The degradation pathway of P-aminophenol wastewater was determined. • Reduce the electrode activation barrier to promote the formation of •OH. [ABSTRACT FROM AUTHOR]

• The effect of Fe 2 O 3 on the leaching behavior of Pb in fly ash was investigated. • The mechanism of Pb leaching behavior was revealed based on phase transformation. • The PbFe 12 O 19 effectively inhibit the leaching of Pb in thermal treated fly ash. This study investigated the leaching behavior of Pb in hazardous waste incineration fly ash (HWIFA) after adding Fe 2 O 3 thermal treatment and revealed the leaching mechanism of Pb from the perspective of phase transformation. The static leaching results showed that at 600 °C-1300 °C, with the addition of Fe 2 O 3 increased, the Pb leaching toxicity continued to decrease. The dynamic results indicated that as the thermal treatment temperature was higher than 1100 °C, the addition of Fe 2 O 3 can effectively inhibit the dynamic leaching of Pb in HWIFA. Meanwhile, the inhibition effect was not very closely related to the amount of Fe 2 O 3. The addition of Fe 2 O 3 can react with PbO to form PbFe 12 O 19 , which has a better stability. The appearance of PbFe 12 O 19 was the main reason for adding Fe 2 O 3 to enhanced the immobilization of Pb. However, the amount of Fe 2 O 3 should be carefully controlled to avoid an excessive reducible fraction of Pb in the thermal treated HWIFA, which will affect the long-term stability of Pb. [ABSTRACT FROM AUTHOR]

In this study, the electrodes (PbO 2 , PbO 2 –SiO 2 , PbO 2 –ZrO 2 and PbO 2 –SiO 2 –ZrO 2) were prepared by galvanostatic electrodeposition in a lead nitrate system and used as anode materials for trivalent chromium plating. Physical characterizations show that the successful doping of SiO 2 and ZrO 2 can refine the grain of PbO 2. Electrochemical tests show that the PbO 2 –SiO 2 –ZrO 2 electrode has good electrocatalytic activity and corrosion resistance, which is mainly attributed to the increase of active surface area. In the process of trivalent chromium plating, the initial and increasing range of the cell voltage of the PbO 2 –SiO 2 –ZrO 2 electrode were the lowest, and the amount of hexavalent chromium generated was much smaller than that obtained using the pure PbO 2 electrode, which had obvious advantages in energy savings. This study provides a concise method for PbO 2 electrode modification and provides a reference for the subsequent use of anode materials for trivalent chromium plating and electrodeposition of other metals. [Display omitted] • The PbO 2 –SiO 2 –ZrO 2 electrode doped by nano-oxides was prepared via electrodeposition. • The electrode a large active surface area and excellent electrocatalytic activity. • The functions of SiO 2 and ZrO 2 are to refine grains and promote OER, respectively. [ABSTRACT FROM AUTHOR]

Lead dioxide (PbO 2) is a common anode for wastewater treatment in electrochemical oxidation studies thanks to its high oxygen evolution potential, great hydroxyl radical productivity, and low cost. There has been much research focusing on PbO 2 preparation and application from different perspectives in recent years. In this paper, with "PbO 2 degradation performance optimization" as the clue, electrode modification strategy and operation condition are systematically reviewed, together with the standard evaluation indexes of electrical and electrochemical properties for PbO 2. The electrodeposition processes can be divided into substrate and interlayer selection, electrodeposition bath adjustment, energy input modulation and new configuration introduction, impacting the catalytic activity and stability. Organic pollutants degradation is a significant application aspect of PbO 2. Four major influence factors in the electrochemical degradation process are discussed, including external circuit control, co-existing ions, solution physicochemical properties and reactor configuration. Other couplings and combination technologies are introduced based on electrochemical oxidation with PbO 2 anode. Further, the future research directions of PbO 2 anode in wastewater treatment are forecasted. [Display omitted] [ABSTRACT FROM AUTHOR]

The zinc electrowinning process demands considerable energy, prompting the quest for energy-efficient solutions to curtail costs. Hence, the development of energy-saving anode materials for zinc hydrometallurgy is an important issue. Herein, multilayered PbO 2 film materials were prepared through thermal decomposition and composite electrodeposition, yielding a new PbO 2 –ZrO 2 electrode featuring ZrO 2 particles as the second phase for energy-saving zinc electrowinning. The introduction of ZrO 2 leads to reduced PbO 2 crystal size, heightened the specific surface area of the electrode, and preferential growth of crystal planes. Electrochemical tests underscore that the PbO 2 –ZrO 2 electrode manifests a reduced charge-transfer resistance (R ct) and overpotential alongside a 46.15 % extension in service life compared to the pure PbO 2 electrode. Simulated zinc electrowinning experiment affirms PbO 2 –ZrO 2 electrode has a 3.63 % surge in the current efficiency and a substantial 244.61 kWh/t reduction in energy consumption relative to the traditional Pb–0.6wt%Ag anode. This study provides a strategic framework for designing and developing cost-efficient, cost-effective anode materials, promoting advancements in energy conservation and consumption reduction within zinc electrowinning processes. • A novel gradient film PbO 2 –ZrO 2 electrode was developed for zinc electrowinning. • The PbO 2 –ZrO 2 (10 g/L) electrode service life is improved by ∼46.15 %. • The current efficiency is higher (90.52%), and energy consumption is lower (2956.71 kW/t). • The introduction of ZrO 2 particles increases the specific surface area of the electrode. [ABSTRACT FROM AUTHOR]

[Display omitted] • The thermochemical reaction mechanism of PbO 2 with (NH 4) 2 SO 4 was studied. • The PbSO 4 was prepared by low-temperature roasting of (NH 4) 2 SO 4 mixed with spent lead paste. • Recovery of NH 4 +, SO 4 2− and CO 3 2− for regeneration of (NH 4) 2 SO 4 and (NH 4) 2 CO 3. During the process of recycling lead from waste lead-acid batteries, how to minimize the wastage of chemical reagents and prevent secondary pollution is a significant research subject. In this study, a method for preparing α-PbO based on low-temperature thermochemical reduction of PbO 2 was proposed. Using (NH 4) 2 SO 4 as the roasting agent, the purity of PbSO 4 in spent lead paste was improved by reducing PbO 2 at low temperatures. The thermochemical mechanism revealed that the thermochemical process consists of three different stages of (NH 4) 2 SO 4 decomposition and PbO 2 reduction. The purity of PbSO 4 in spent lead paste could be increased to 98.43 % by controlling the thermal reaction conditions (M (SO 4 2−: T Pb) molar ratio of 1:1, roasting temperature, and time of 340 °C and 1.5 h, respectively). Then, the desulfurization of PbSO 4 with (NH 4) 2 CO 3 obtained PbCO 3 , and α-PbO with a purity of 96.87 %-98.57 % could be obtained by pyrolysis of PbCO 3. Finally, 95.63 % of NH 4 +, 97.34 % of SO 4 2−, and 77.71 % of CO 3 2− could also be recovered for the regeneration of (NH 4) 2 SO 4 and (NH 4) 2 CO 3. This study provides a feasible technology for green recycling of spent lead paste. [ABSTRACT FROM AUTHOR]

• A quasi-single-crystal PbO 2 is successfully synthesized by hydrothermal method. • The oriented exposed surfaces are identified as (110) and (101) facets. • The quasi-single-crystal PbO 2 is more conducive to electrochemical ozone production. • The PbO 2 (110) facet is thermodynamically more favorable in the presence of high PVP concentration. The crystal facet of PbO 2 has been proved to be a key factor affecting its electrochemical ozone production (EOP) performance. However, PbO 2 with smooth and uniform crystal surface and single-crystal nature, which is the basis and prerequisite for PbO 2 crystal facet engineering, has not yet been reported. In this study, by adding polyvinylpyrrolidone (PVP) as a facet modifier during the hydrothermal synthesis, a quasi-single-crystal PbO 2 (PVP:Pb(CH 3 COO) 2 ·3H 2 O=48:100, PVP-48) with (110) and (101) exposed facets was successfully synthesized. Compared with commercial PbO 2 prepared by electrochemical deposition, PVP-48 exhibits excellent electrochemical catalytic activity due to its special crystal structure, and achieves the highest current efficiency of 11.9 % at a current density of 0.83 A/cm2. Further calculations show that PVP prefers to adsorb onto the (110) facet of the lead dioxide and reduces its surface energy, thereby exposing the (110) facet more readily. This work demonstrates the importance of PbO 2 facets composition and provides new ideas for further controllable synthesis of PbO 2 with specific facet structure and higher EOP efficiency. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel Si 3 N 4 -PbO 2 nanocomposite electrode was fabricated and characterized. • Si 3 N 4 -PbO 2 electrode showed extreme long accelerated life. • Si 3 N 4 -PbO 2 electrode could treat sulfathiazole and sulfonamides efficiently. • Degradation mechanism of sulfathiazole were explored by GC-MS. • Several theoretical calculations were established by VASP and Multiwfn software. To lengthen the lifetime and extend the potential commercial applications of lead dioxide electrode, herein, a novel multilayer heterojunction Ti/ SnO 2 -Sb 2 O 3 / graphene oxide/ carbon nanotube/ Si 3 N 4 -PbO 2 electrode (Si 3 N 4 -PbO 2 electrode) was fabricated by co-electrodeposition process that doping Si 3 N 4 nanoparticles in eletroplating solution. Various spectroscopic and microscopic techniques, including scanning electron microscopy (SEM) equipped with energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS), were employed to characterize the surface of the fabricated electrode. The EDS analysis confirmed the successful attachment of 5.49 %wt Si and 2.46 %wt N elements from Si 3 N 4 nanoparticles onto the PbO 2 surface, while the XRD results indicated a shift in the preferred orientation of PbO 2 grains from β(1 1 0) to β(1 0 1). The water adsorption energy and ·OH desorption energy in the electrocatalysis process were determined to be 0.71 eV and 0.241 eV through theoretical calculating. Subsequently, the Si 3 N 4 -PbO 2 electrode was employed as an anode for the electrocatalytic degradation of sulfathiazole-simulated wastewater and real sulfonamides wastewater. Under optimized conditions determined via response surface methodology (RSM), the COD degradation efficiency reached 69.37 % for sulfathiazole and 62.35 % for real sulfonamides wastewater. The final COD concentration of the real sulfonamides wastewater was reduced to 77.05 mg/L, under the national urban sewage discharge standard. Finally, the degradation mechanism and pathway of sulfathiazole has been arranged based on the electron spin resonance (ESR), cyclic voltammetry (CV), while the intermediates were detected by Gas Chromatography-Mass Spectrometer (GC-MS) and the reactive sites of sulfathiazole were predicted by using Fukui function. [ABSTRACT FROM AUTHOR]

The PbO 2 /Co 3 O 4 composite electrodes were synthesized using the composite co-deposition method, which involved the incorporation of Co 3 O 4 nanoparticles into a PbO 2 coating. These composite electrodes were employed as anodes for phenol electrooxidation in wastewater treatment. The results demonstrate that the PbO 2 /Co 3 O 4 composite electrode exhibits a three-dimensional porous structure, leading to a significant increase in the electrochemically active surface area. Electrochemical measurements indicate that the composite electrode achieves a minimum oxygen evolution potential of 526.5 mV. Moreover, the electrode facilitates the indirect degradation of phenol, even at low voltage (0.45 V). The unique structure, improved conductivity, and enhanced surface area of the electrode contribute to its exceptional performance in phenol degradation. Additionally, this approach offers the potential for synergistic integration with other treatment methods, providing a sustainable and energy-efficient solution for removing persistent organic compounds from wastewater. [Display omitted] • The PbO 2 /Co 3 O 4 has a high electrochemically active surface area. • PbO 2 is served as a conductive platform for Co 3 O 4. • The PbO 2 /Co 3 O 4 composite has low evolution potential. • The oxidation of phenol at 450 mV using PbO 2 /Co 3 O 4 anode. • This approach reduces energy in a hybrid treatment process. [ABSTRACT FROM AUTHOR]

• Pure perovskite α-FAPbI 3 film was synthesized by the electrodeposition method. • MABr addition can suppress the size and number of pinholes in the perovskite FAPbI 3 film. • The best efficiency of PbO 2 induced ETL-free FAPbI 3 solar cells is nearly 20 times higher than that of PbI 2 based solar cells. Formamidinum based lead halide (α-FAPbI 3) perovskite solar cells have refreshed the highest power conversion efficiency several times in the best Research-Cell Efficiency Chart due to its suitable bandgap. However, the non-perovskite yellow phase δ-FAPbI 3 is easily formed in the process of synthesizing the black phase α-FAPbI 3. To solve this problem, we provide a new method to grow pure perovskite α-FAPbI 3 film through electrodeposited lead dioxide (PbO 2). The as-prepared α-FAPbI 3 shows an obvious absorption edge despite some pinholes formation during the reaction of PbO 2 and FAI. By adding extra MABr during the synthesis of α-FAPbI 3 , the size and number of pinholes can be effectively suppressed. Thus, the optimal electron-transport-layer (ETL)-free perovskite FAPbI 3 solar cells show a drastically elevated power conversion efficiency (PCE) of 10.73%, which is nearly 20 times higher than that of PbI 2 based perovskite solar cells with the same device structure. These results demonstrate that the growth of PbO 2 film by the electrodeposition method provides a new way for the preparation of high-efficiency perovskite solar cells. On this basis, combined with the introduction of the ETL (TiO 2 , SnO 2 , etc.) and the optimization of device fabrication processes, the PCE of the perovskite solar cells obtained by this method may be further improved in the future. [ABSTRACT FROM AUTHOR]

Lead-acid batteries rapidly response to instantaneous high-current, rendering them particularly effective for high-power applications, including power traction batteries, starter batteries, and start-stop systems. However, issues arise during intense working rate (6–10C), causing significant polarization that leads to severe oxygen evolution side reactions and softening and shedding of positive active material (PAM), limiting the battery's cycle life. This study introduces a tin dioxide (SnO 2) coated rice husk silica (RH-SiO 2) composite as an positive additive in lead-acid batteries. The composite (SnO 2 /RH-SiO 2) has a hierarchical pore structure from RH-SiO 2 , provides a robust conductive framework. The lattice structure of the SnO 2 is similar to that of PbO 2 , while induces the formation of a PbSnO 3 intermediate phase during formation process. SnO 2 /RH-SiO 2 can also accelerates lead dioxide deposition and improves the interphase conversion efficiency, while significantly enhances the transformation of α- and β-PbO 2 , leading to a 20.7% increase in discharge specific capacity. Compared to a standard battery, up to 3.7 times longer at 100% deep discharge cycle life and 4.7 times longer in start-stop-mode testing. In our finding the SnO 2 /RH-SiO 2 composite serves as a highly effective additive for augmenting the performance and longevity of lead-acid batteries in high-power applications, presenting a significant advancement in battery technology. [Display omitted] • Hierarchical porous SnO 2 /RH-SiO 2 is prepared as LAB positive additives. • SnO 2 /RH-SiO 2 significantly enhances ion conductivity due to better ion transport. • Batteries with SnO 2 /RH-SiO 2 demonstrate a remarkable extension in cycle life. • SnO 2 /RH-SiO 2 battery shows an exceptional performance in start-stop operation modes. • The introduction of SnO 2 leads to perovskite lattice defects in Pb 16 Sn 16 O 48. [ABSTRACT FROM AUTHOR]

Pulsed and constant direct current electrodepositions were applied to synthesize PbO 2 -IrO 2 nano-composites on Ti substrate. By compositing PbO 2 with nano-sized IrO 2 particles, a suitable anode was prepared for zinc electrowinning that decreases the electrocatalytic activity for oxygen evolution reaction overpotential (OER) while increasing the electrochemical active surface area and the electrocatalytic activity for OER. To provide PbO 2 -IrO 2 nano-composites on Ti substrate with Sb 2 O 3 interlayer, current density, temperature, and time of anodization are optimized using the one-at-the-time method. The optimal condition for the anode involves a DC time of 1 h, incorporating 2 g L-1 of IrO 2 nanoparticles, maintaining a current density of 50 mA cm− 2 for the DC mode, and setting the pulse off-time (t off) to 770 ms. Based on the electrochemical evaluations in a simulated zinc electrowinning electrolyte, the effect of IrO 2 nanoparticles on the catalytic activity of Ti/β-PbO 2 anode for OER was determined. Anodic polarization curves showed that the OER overpotential of PbO 2 -IrO 2 micro-composite and PbO 2 -IrO 2 nano-composites at a current density of 10 mA cm-2 decreased to 0.471 V, respectively, compared to 0.711 V for pure PbO 2. The Nyquist plots in the OER zone confirm that the PbO 2 -IrO 2 nano-composite anode exhibits the lowest Rct 2.79 Ω compared to 6.0 Ω and 9.46 Ω for PbO 2 -IrO 2 micro-composite and pure PbO 2 , which can be attributed to the presence of electro-catalytic IrO 2 nanoparticles. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • Synthesis high-efficiency catalyst of CNTs confined PbO 2 on BDD substrate. • Features of PbO 2 inside or outside CNTs are investigated. • Mechanism of increasing electrocatalytic activity is revealed. • Confinement effect enhances catalytic activity and avoids pollution of PbO 2. Realizing highly efficient catalysis with high stability in complex chemical environments remains a major challenge for advanced oxidation processes. Here, confined lead dioxide (PbO 2) nanoparticles in carbon nanotubes (CNTs) on boron-doped diamond (BDD) substrate is designed and fabricated as a heterogeneous catalyst for antibiotic treatment, achieving ultra-efficient degradation of chlortetracycline (CTC) with high reaction rate and stability. The maximum degradation rate of CTC reaches 98.8 % in 120 min, and it remains 91.0 % after ten cycles, which are significantly higher than that proposed by the contrast catalysts. The excellent degradation performance of this heterogeneous catalyst is mainly attributed to three factors: (i) the prepared PbO 2 nanoparticles with an average size of 5 nm are confined in CNTs, providing more active sites and higher electron transfer rate; (ii) secondary pollution and catalyst deactivation of PbO 2 are avoided by protecting CNTs; (iii) BDD shows strong capacity for mineralizing organic compounds related to the high oxygen evolution reaction potential. This finding provides a novel strategy for advanced oxidation processes in environmental remediation. [ABSTRACT FROM AUTHOR]

The anode materials PbO 2 –MnO 2 , PbO 2 -CoO x , and PbO 2 –MnO 2 -CoO x, were prepared by anodic oxidation in the nitrate system. The microstructure and chemical composition of the anode materials were characterized by scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). The electrochemical performance of the anode materials were studied by linear sweep voltammetry (LSV), electrochemical impedance spectroscopy (EIS) and Tafel polarization curves (Tafel). The results indicate that the coating of PbO 2 –MnO 2 -CoO x anode materials with a spherical structure, and the PbO 2 –MnO 2 and PbO 2 -CoO x anode materials with a stacked pellet structure. Compared with PbO 2 , PbO 2 –MnO 2, and PbO 2 -CoO x anodes, PbO 2 –MnO 2 -CoO x anodes have the maximum exchange current density (j0) values, the minimum charge transfer resistance (R ct) values, and minimum the self-corrosion current density (i corr) in electrowinning Copper solution. The cell voltage of Cobalt-containing Manganese anode material is lower than that of traditional Pb–Sn–Sb anode material, Indicating that the Cobalt-containing Manganese anode material is of practical value to reduce energy consumption. Image 1 • The PbO 2 –MnO 2 –Co 3 O 4 anode material was prepared by anodic electrodeposition method. • The anode material has excellent electrocatalytic activity and stability. • Co2+, Mn2+ into the coating can improve the electrocatalytic activity of the anode. [ABSTRACT FROM AUTHOR]

In the present work, a novel Pb-0.6%Sb/α-PbO 2 /β-PbO 2 composite electrode with quantitatively phases of α or β-PbO 2 was obtained by electrodeposition in methanesulfonic acid (MSA) and further investigated in novel flow battery. The physicochemical properties of lead dioxide were analyzed by anodic polarization curves, X-ray powder diffraction (XRD), scanning electron microscopy (SEM), electrochemical impedance spectroscopy (EIS) and Tafel curves. Results showed that the selection of temperature ranges was found to cause a quantitative difference in the formation of α/β-PbO 2 phases, as it made interval effects on the overpotential that was the primary control condition to affect transfer proces.The precise conditions of obtaining α or β-PbO 2 phases by varying temperatures were confirmed and samples were prepared to be tested in long-period galvanostatic electrolysis. By comparing, the electrode (deposition time-α&β: 2 h&2 h) showed the best physicochemical properties, which could effectively improve the energy storage and extend the lifetime (63.6 h) compared with the traditional lead dioxide electrodes (24.5 h) in novel flow battery. • Precise conditions of obtaining relative pure α/β-PbO 2 phases was investigated. • Temperature ranges cause difference in the formation of α/β-PbO 2 phases. • Electrode (α&β: 2 h&2 h) has the longest lifetime (63.6 h) in novel flow battery. [ABSTRACT FROM AUTHOR]

• Graphite/β-PbO2 anode was used to improve the biodegradability of textile wastewater. • Process optimization by genetic algorithm. • Electrochemical degradation mechanism of methylene blue. • Reusability and stability of graphite/β-PbO 2 anode was investigated. An anodic oxidation process with graphite anode coated with lead dioxide (G/β-PbO 2) was optimized for the degradation of methylene blue (MB) and the treatment of real textile wastewater. The G/β-PbO 2 anode was prepared by the electrochemical precipitation method. The scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and X-ray diffraction (XRD) analyses confirmed the successful coating of graphite substrate with the β-PbO 2 film. The effect of four independent variables including pH, reaction time, current density, and electrolyte concentration of Na 2 SO 4 on the performance of the electrochemical oxidation system was modeled by using a complete central composite design and was then optimized by genetic algorithm method. The accuracy of the proposed quadratic model by CCD was confirmed with p-value <0.0001 and adj-R2 > 0.9. The optimum conditions for solution pH, reaction time, current density, and Na 2 SO 4 electrolyte concentration were obtained to be 5.75, 50 min, 10 mA/cm2, and 78.8 mg/L, respectively. In these conditions, the experimental removal efficiencies of MB using G/β-PbO 2 and graphite anodes were 96.2% and 68.3%, respectively. The electrochemical removal of MB using both G/β-PbO 2 and graphite anodes well followed the pseudo-first-order reaction (R2 > 0.9). Cyclohexane, cyclohexa-2,5-dien-1-ylium, and N-(sec -butyl) aniline were the most abundant intermediates identified by LC-MS analysis. However, the complete mineralization of MB was achieved in 60 min. The optimized anodic oxidation process successfully improved the biodegradability of real textile wastewater (B O D / C O D > 0.4). [ABSTRACT FROM AUTHOR]

The electrochemical behavior of PbO 2 /PbSO 4 electrode is investigated in 4.5 M H 2 SO 4 in presence of three surfactants, Sodium Dodecyl Sulfate (SDS), Cetyltrimethylammonium bromide (CTAB) and Sodium tripolyphosphate (STPP), using cyclic voltametry, electrochemical spectroscopy impedance and galvanostatic discharge as techniques. The micro morphology of the surface of the modified PbO 2 electrodes is examined by scanning electron microscopy. The results show that SDS and CTAB when added in the electrolyte could refine the coating particles and change the roughness of the surface of the electrode leading to a thin film of PbO 2 with amorphous character. In addition, SDS and CTAB shift the hydrogen evolution potential towards more negative values, improve the discharge capacity of the anodic layer and accelerate the charge transfer. Under cathodic polarization, CTAB presents the lowest value of the charge transfer resistance R ct. In the contrary, STPP shifts the oxygen evolution potential towards more positive values, passivates the surface of the electrode and inhibits completely the reaction of PbO 2 formation. [ABSTRACT FROM AUTHOR]

• A paired recovery of metal ions from e-waste was developed in the RCE electrochemical reactor. • Bimetallic deposition of copper and silver was achieved at the RCE cathode. • The Pb (II) ions were anodically deposited as lead dioxide. This work proposes the paired electrochemical recovery of metal ions, cathodically and anodically, from emulated e-waste leached solutions. Under this methodology, the recovery of a bimetallic deposit of copper-silver at the cathode, and lead dioxide at the anode, was successfully achieved in an undivided rotating cylinder electrode (RCE) electrochemical reactor. The RCE electrochemical reactor was implemented at 300 rpm and different current densities, 50, 40, 30, 20, and 10 mA/ cm2. Different compositions of the bimetallic copper-silver deposits were obtained depending on the current density applied, while in the anodes, only the deposition of lead dioxide was performed at any current density. The concentration depletion of metal ions was determined at different intervals of time. The cell voltage, cathode, and anode potential vs. SCE, were continuously monitored, and the values were useful to evaluate the energetic performance of the RCE electrochemical reactor. Figures of merit are presented to describe the performance of the RCE electrochemical reactor in the paired recovery of metal ions from emulated e-waste leached solution. [ABSTRACT FROM AUTHOR]

Tris (2-butoxyethyl) phosphate (TBOEP) has gained significant attention due to its widespread presence and potential toxicity in the environment. In this study, the degradation of TBOEP in aquatic media was investigated using electrochemical oxidation technology. The anode Ti/SnO 2 –Sb/La–PbO 2 demonstrated effective degradation performance, with a reaction constant (k) of 0.6927 min−1 and energy consumption of 1.24 kW h/m3 at 10 mA/cm2. CV tests, EPR tests, and quenching experiments confirmed that indirect degradation is the main degradation mechanism and ·OH radicals were the predominant reactive species, accounting for up to 93.8%. The presence of various factors, including Cl−, NO 3 −, HCO 3 − and humic acid (HA), inhibited the degradation of TBOEP, with the inhibitory effect dependent on the concentrations. A total of 13 intermediates were identified using UPLC-Orbitrap-MS/MS, and subsequent reactions led to their further degradation. Two main degradation pathways involving bond breaking, hydroxylation, and oxidation were proposed. Both Flow cytometry and the ECOSAR predictive model indicated that the intermediates exhibited lower toxic than the parent compound, resulting in a high detoxification rate of 95.9% for TBOEP. Although the impact of TBOEP on the phylum-level microbial community composition was found to be insignificant, substantial alterations in bacterial abundance were noted when examining the genus level. The dominant genus Methylotenera , representing 17.4% in the control group, decreased to 6.9% in the presence of TBOEP and slightly increased to 8.7% in the 4-min exposure group of degradation products. Electrochemical oxidation demonstrated its effectiveness for the degradation and detoxification of TBOEP in aqueous solutions, while it is essential to consider the potential impact of degradation products on sediment microbial communities. [Display omitted] • Electrochemical oxidation technology can effectively degrade TBOEP. • TBOEP degradation is mainly through hydrogenation, oxidation and bond breaking. • TBOEP achieved excellent detoxification, with the detoxification rate of 95.9%. • Treated effluents still have potential impacts on the sediment microbial community. [ABSTRACT FROM AUTHOR]

[Display omitted] • A more compact PbO 2 electrode was prepared by co-doping with Ni and SDS. • Higher O ad content was observed for Ni-SDS-PbO 2. • The production of •OH was significantly improved. • The electrocatalytic activity for tetracycline degradation was greatly enhanced. A PbO 2 electrode co-doped with nickel (Ni) and sodium dodecyl sulfate (SDS) was prepared with TiO 2 nanotube as the substrate by a simple electro-deposition method. The morphology, composition and structural information were characterized by SEM, XPS and XRD. The techniques of linear sweep voltammetry and electrochemical impedance spectroscopy were used to investigate electrochemical properties. The characterizations indicated that an increased OEP value and a higher O ads content were obtained for Ni-SDS-PbO 2. The experimental results confirmed that the yield rate of ·OH by Ni-SDS-PbO 2 was 2.21 times as high as that by the undoped PbO 2. Accordingly, the electrocatalytic degradation of tetracycline by Ni-SDS-PbO 2 was the fastest. The corresponding pseudo-first-order kinetic constant for Ni-SDS-PbO 2 was the highest (0.0504 min−1), and it was 2.83 times as high as that for the pristine PbO 2. The increased electrocatalytic performance of Ni-SDS-PbO 2 and its enhanced stability could be attributed to the co-modification of Ni and SDS. [ABSTRACT FROM AUTHOR]

A versatile integrated rechargeable hybrid system by engineering a fibrous polyaniline negative electrode is proposed to essentially solve the existing problems of lead-acid battery, which include the dendrite formation, poor cycle stability, water loss, environmental hazards derived from the electrochemical functionality of negative lead. We demonstrate that polyaniline negative electrode could result into the boosting performance of the integrated system due to the reaction mechanism of polyaniline, which involves the transition of leucoemeraldine/polaronic emeraldine together with the doping/dedoping of dopant. As a result, the integrated system delivers an admirable specific capacity, effectively avoids the sulfuric acid salinization, presents considerable power and energy density, and distinctly enhances the cycle stability. Meanwhile, the reaction kinetics of the hybrid system is also investigated and the controllable mechanism transformation from the pseudo-capacitive to battery-type behavior could be realized by regulating the mass ratio. In addition, low employment of lead substances further increases its ecological acceptability, reflecting a promising prospect of application as an efficient energy storage system in the future. Moreover, the strategy features simple configuration and easy operation without altering the original structure, which could further bridge the gap between lead-acid battery and supercapacitor. • A versatile integrated rechargeable lead dioxide-polyaniline hybrid system is proposed. • The hybrid system inherits the merits of lead-acid battery and supercapacitor. • Controllable mechanism transition depends on the mass ratio. • The integrated system with more economically viable could be considered as an efficient energy storage system. [ABSTRACT FROM AUTHOR]

• Charcoal gasification with both air and CO 2 led to the formation of CO. • Charcoal gasification started at 300 °C with the air and at 600 °C with CO 2. • 5% of CO is enough to convert hematite into magnetite. • A low CO concentration makes the reduction safer and less energy-consuming. Hematite-containing material is accumulated during exploitation and beneficiation of magnetite ore, thus forming tailings and other industrial wastes. Hence, processing the low-grade hematite ore becomes extremely important for the metallurgical industry. The transformation of weakly magnetic hematite into magnetite can enhance the efficiency of magnetic separation. In this work, chemical reduction of hematite to magnetite in an atmosphere with different gas composition was investigated. Gasification of charcoal in the flow of both air and carbon dioxide led to the formation of carbon monoxide. The output gas containing carbon monoxide was found to be an effective reductant for the transformation of hematite into magnetite. Even 5% of CO was sufficient to convert hematite into magnetite, which resulted in an increase in magnetization up to 85 Am2/kg. The kinetic analysis indicated that the reduction of hematite to magnetite is a single-step process, which can be described using the first-order reaction model. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Selected materials (cathodes) and Ti/PbO 2 (anode) were used for nitrate removal from water. • High nitrate removal was achieved by using carbon paper cathode and Ti/PbO 2 anode. • Nitrate removal and ammonia formation showed to increase with low current density. • The presence of chloride ions was found not to affect nitrate removal but to destruct ammonia and nitrite. • Electrochemical nitrate removal mechanism was confirmed by a designed experiment. Abstract Selected cathodes, including carbon paper (C) and plates of titanium (Ti), iron (Fe), copper (Cu) and aluminum (Al), combined with a Ti/PbO 2 anode (a lead dioxide electrodeposited on titanium plate) were employed for studying quick nitrate removal from neutral water in this work. Cathode materials, current densities and the presence of chloride ions (Cl−) in water were investigated as to the effects on nitrate removal. Nitrate and two main reduction products, i.e. nitrite and ammonia, were measured using ion chromatography. The results showed that the nitrate removal efficiency decreased in the order of cathode materials: C > Ti ≈ Fe > Cu > Al. The optimum removal was achieved to be 47.7% for a 50 mg-N/L nitrate solution by using carbon paper cathode and Ti/PbO 2 anode after 120-min electrolysis with a current density of 40 mA/cm2. The subsequent experimental results showed that the current density of 20 mA/cm2 is also high enough for achieving a considerable nitrate removal. Moreover, the presence of Cl− in water was proven to have no significant effect on nitrate removal but be able to promote the destruction of nitrite and ammonia ions, resulting in the virtual decrease in nitrate and total nitrogen. By a designed experiment, the nitrate removal pathway was confirmed to include a reciprocating reduction (of nitrate) and oxidation (of nitrite and ammonia), both of which can lead to the removal of nitrate as well as total nitrogen from nitrate-containing wastewater by generation of nitrogen. cathodes and anodes may play different roles. [ABSTRACT FROM AUTHOR]

Graphical abstract In traditional industrial production, cathode copper is co-prepared by both the pyrometallurgical process and wet electrolytic refining method. In this work, a non-dissolving electrode lead dioxide was used as an anode in an electrolysis experiment, and copper oxide was added to maintain the concentration of copper ions in the electrolyte to improve the quality of cathode copper and current efficiency in the electrolytic copper process. The average current efficiency of electrolysis for 8 h was 96.33% with the new non-dissolved anode, which was 2.58% higher than that of the traditional dissolved anode. Moreover, the electrolyte can be recycled after use with the modified parameter and technology. This new process can save energy and reduce material consumption for copper production in the hydrometallurgical industry. In addition, this paper provides a new method of improving the current efficiency and product quality in the electrolytic process of industrial production of metals. Highlights • A non-dissolving electrode was used as an anode in the electrolytic refining. • CuO powder was added to maintain the Cu2+ concentration in the electrolyte. • Effect of three electrolytes on the electrolytic process was analyzed systematically. • After using the modified parameter and technology, the electrolyte can be recycled. Abstract In traditional industrial production, cathode copper is co-prepared by both the pyrometallurgical process and wet electrolytic refining method. In this work, a non-dissolving electrode lead dioxide was used as an anode in an electrolysis experiment, and copper oxide was added to maintain the concentration of copper ions in the electrolyte to improve the quality of cathode copper and current efficiency in the electrolytic copper process. The method could avoid energy consumption in the pyrometallurgical process. The effect of three kinds of electrolytes on the macroscopic morphology, microstructure, current efficiency, purity, and crystal composition of the cathode copper was analyzed. In the electrolysis experiment, Cu 2 O and CuO phases were observed in the cathode copper by using electrolyte A for a long time. With the use of electrolyte B, the purity of the products did not meet the standard of the cathode copper. With the use of electrolyte C, the products prepared by electrolysis four times for 8 h or 2 h each time met the standards for morphology, current efficiency, and purity. The average current efficiency of electrolysis for 8 h was 96.33% with the new non-dissolved anode, which was 2.58% higher than that of the traditional dissolved anode. Moreover, the electrolyte can be recycled after use with the improved electrolyte and process. This new process can save energy and reduce material consumption for copper production in the hydrometallurgical industry. In addition, this paper provides a new method of improving the current efficiency and product quality in the electrolytic process of industrial production of metals. [ABSTRACT FROM AUTHOR]

Highlights • PbO 2 nanorod array was coated on electrode by template-free pulse potential method. • Chrysanthemum-like array of PbO 2 nanorod was prepared by pulse potentiostatic method. • Chrysanthemum-like array of PbO 2 nanorod revealed a good supercapacitor property. Abstract PbO 2 electrode is one of crucial materials in electrochemical field, however, the fabrications of nanostructured PbO 2 materials are highly confined to the template method. In this work, the nanostructured PbO 2 materials were controllably synthesized by template-free electrodeposition method. It is found that the microstructure of PbO 2 material was highly depended on the electrochemical deposition models, i.e., cyclic voltammetry (CV) method, potentiostatic method (PM), pulse potentiostatic method (PPM) and pulse galvanostatic method (PGM). Especially, PbO 2 nanorod built by nanoparticles with chrysanthemum-like array synthesized in the absence of template by pulse potential deposition method showed high specific capacitance and good stability for supercapacitor application. [ABSTRACT FROM AUTHOR]

Abstract Electrochemical degradation of hexazinone in aqueous solution using Bi-doped PbO 2 electrodes as anodes was investigated. The main influencing parameters on the electrocatalytic degradation of hexazinone were analyzed as function of initial hexazinone concentration, current density, initial pH value and Na 2 SO 4 concentration. The experiment results showed that the electrochemical oxidization reaction of hexazinone fitted pseudo-first-order kinetics model. 99.9% of hexazinone can be decontaminated using Bi-doped PbO 2 electrode as anode for 120 min. Comparing with pure PbO 2 electrode, the Bi-doped PbO 2 electrodes possess higher hexazinone and COD removal ratio, higher ICE and lower energy consumption in the electrocatalytic degradation process. The results revealed that electrochemical oxidation using Bi-doped PbO 2 anodes was an efficient method for the elimination of hexazinone in aqueous solution. The electrocatalytic oxidization mechanism of hexazinone with Bi-doped PbO 2 anode was discussed, then the possible degradation pathway of hexazinone with two parallel sub-routes was elucidated according to 15 intermediates identified using HPLC-MS. Highlights • Bi-doped PbO 2 electrode was adopted to eliminate hexazinone in water. • Operating parameters of hexazinone degradation were optimized. • 99.94% of hexazinone was electrochemically decontaminated by Bi PbO 2 electrode. • Bi-doped PbO 2 electrode exhibits high hexazinone degradation capability. • The degradation intermediates of hexazinone were identified and pathway was proposed. [ABSTRACT FROM AUTHOR]

Abstract Various structured PbO 2 electrodes were prepared by surfactant-assisted anodic electrodeposition method. PbO 2 -PEG thin-film electrode is composed of small particles and shows a smooth surface. PbO 2 -PVA electrode displays a unique structure in which the PbO 2 particles are embed in the PVA network structure. PbO 2 -AOT electrode consists of bull-horn like particles. The morphologies and structures of PbO 2 electrodes are highly influenced by the surfactant. PEG and PVA can decrease the particle size of PbO 2 particle and AOT can dramatically alter the morphology of PbO 2 particle. PbO 2 -PEG, PbO 2 -PVA, and PbO 2 -AOT electrodes exhibit excellent electrocatalytic activity, stability, corrosion resistance, and long service life compared with bare PbO 2 electrode. This work demonstrates the relationship between the structure and electrochemical performances of PbO 2 electrodes, and provides a feasible approach to fabricate stable structured electrode. Highlights • Various structured PbO 2 thin-film electrodes are prepared. • Electrochemical performance of PbO 2 depends on its structure and morphology. • PbO 2 -PEG electrode exhibits the best performance. • The performance of PbO 2 -PEG electrode arises from its smooth and dense structure. [ABSTRACT FROM AUTHOR]

Lead-carbon batteries (LCBs) possess the dual functions of supercapacitors and lead-acid batteries (LABs), which can meet the demand for renewable energy and in mild hybrid electric vehicles (HEVs) for energy storage and short-term high-rate charging and discharging. With the cycle of high-rate partial state-of-charge (HRPSoC), irreversible sulfation of the positive electrode becomes increasingly prominent and serious, resulting in low discharge capacity and short cycle life. In this study, to reduce the sulfation of the positive plate and improve the battery capacity and cycle life, a lead dioxide nanoparticle-doped graphene oxide (nano-PbO 2 /GO) composite material with dual functions of conducting and nucleating was prepared by a hydrothermal method as a positive electrode additive. The results show that the addition of nano-PbO 2 /GO promotes the formation of a three-dimensional short rod-like structure of PbO 2 nanoparticles in a dendritic arrangement, accelerates the generation of new phases and inhibits the growth of bulk PbSO 4. Moreover, the positive plate with nano-PbO 2 /GO exhibits good electrochemical activity to maintain the stability and reversibility of the electrode redox reaction. Finally, the initial discharge specific capacity of the LCBs with nano-PbO 2 /GO is increased to 153.85 mAh/g, and the HRPSoC cycle life is up to 15658 cycles at a 2 C discharge rate. Overall, the dual functions of nano-PbO 2 /GO greatly alleviate battery sulfation and provide a reference for improving the performance of LCBs by modifying the electrode structure. [Display omitted] • nano-PbO 2 doped graphene composites were successfully prepared. • nano-PbO 2 /GO has electrical conductivity and nucleation. • nano-PbO 2 / GO can deposit nano-PbO 2 and inhibit PbSO 4 growth. • Increased cycle life of batteries with the addition of nano-PbO 2 /GO. • The positive plate forms a micro-nanostructure to mitigate sulfation. [ABSTRACT FROM AUTHOR]

[Display omitted] • Cobalt ferrite was successfully coated on Ti/Ni/PbO x. • The stability of cobalt ferrite for OER was improved. • Ti/Ni/PbOx/CoFe 2 O 4 can be used as both anode and cathode in water splitting. • Innovative arrangement of cobalt ferrite can resist in 0.5 M NaCl + 1 M KOH. The advance of efficient, low-cost, and bifunctional catalysts for seawater splitting to produce hydrogen fuel is a challenge. However, by relying on transition metal-based compounds, a unique and attractive arrangement can be proposed. Here, a four-step process was used for the synthesis of the Ti/Ni/PbO x /CoFe 2 O 4 electrocatalyst. First, thin films of nickel (by cathodic electrodeposition) and lead dioxide (by anodic electrodeposition) were synthesized on the activated titanium substrate. Then, using nitrate solution, CoFe coating with a thickness of ∼ 5 µm was applied. Finally, the coating is oxidized to form cobalt ferrite (CoFe 2 O 4). The structure of the arrangement formed in each step was examined by X-ray diffraction (XRD), Raman, X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FE-SEM), and energy dispersive X-ray spectroscopy (EDS) and the electrocatalytic performances were evaluated in 1 M KOH and 1 M KOH + 0.5 M NaCl solutions by electrochemical methods such as linear sweep voltammetry (LSV), electrochemical impedance spectroscopy (EIS), small amplitude cyclic voltammetry (SACV), accelerated chronopotentiometry (CP), and multi-step CP. The Ti/Ni/PbO x /CoFe 2 O 4 electrode requires an overpotential less than 400 mV at 50 mA/cm2 with Tafel constant of 47.7 V/dec for OER. The results of the stability test in accelerated conditions and the alkaline solution containing chloride ions showed that the special arrangement of the cobalt ferrite electrocatalyst in this work improves its lifetime by more than 5 times compared to the normal cobalt ferrite. The synthesized Ti/Ni/PbO x /CoFe 2 O 4 as a bifunctional electrode requires only a potential of 1.53 V at a current density of 10 mA/cm2 for overall seawater splitting. The dual-purpose properties of the Ti/Ni/PbO x /CoFe 2 O 4 electrocatalyst can be considered for its wide use in the fields of sustainable and renewable energy. [ABSTRACT FROM AUTHOR]

• Electrochemical advanced oxidation processes use a PbO 2 anode and H 2 O 2 electrosynthesis cathode. • A cyclone reactor is a type of process intensification reactor. • The contributions of both PbO 2 anode and H 2 O 2 electrosynthesis cathode are discussed particularly. • Simulation provides a visualized perspective. • Pronounced signals of powerful radicals can be detected, including •OH, SO 4 •−, and 1O 2. Electrochemical advanced oxidation processes are promising tools for pollution abatement but most still lack practical engineering attempts and devices. A type of process intensification reactor for the electrochemical advanced oxidation processes is developed here. The cyclone continuous flow electrochemical reactor adopts a PbO 2 anode and H 2 O 2 electrosynthesis cathode together. A lab-scale cyclone continuous flow electrochemical reactor is fabricated and simulated, which is evaluated using the H-acid wastewater. The contributions of the PbO 2 anode and H 2 O 2 electrosynthesis cathode to pollutant degradation are discussed particularly. A 3-D model is developed to provide a visualized perspective on the reactor performances, including flow distribution, mass transfer, and current distribution. Pronounced signals of powerful radicals can be detected for the PbO 2 H 2 O 2 cyclone reactor, including •OH, SO 4 •−, and 1O 2. It exhibits excellent performances on mass transfer, electrical properties, organic degradation, and space-time yield. Such a strategy presents a promising engineering solution for scale-up and further development toward industrial application. [Display omitted] [ABSTRACT FROM AUTHOR]

The e-waste generation is growing faster than the possibilities of its appropriate recycling or disposal. Improving the efficiency of the metal recovery process electrochemical stage could drive more proper recycling of this waste. This work presents a novel proposal to simultaneously recover metal ions in both electrodes using electrochemical methods to take advantage of electrical charges at the cathode and anode. The simultaneous recovery process here implemented makes use of a leached solution from electronic waste (e-waste) with a high copper concentration and low nickel, iron, silver, and lead content. It was envisaged from the thermodynamic analysis of the leached solution through speciation diagrams. This analysis allows for predicting the potentials at which selective cathodic deposits or codeposits can be obtained with the simultaneous formation of metal oxides at the anode. The information from the thermodynamic study was experimentally corroborated by cyclic voltammetry, and the simultaneous electrochemical process of metal ions was subsequently addressed. At a potential corresponding to 0.195 V vs. NHE, it was possible to obtain a codeposit of copper-silver with simultaneous recovery of lead oxide on the anode. [ABSTRACT FROM AUTHOR]

• The thickness and quality of the films were improved in the photovoltaic devices. • The thin film with 0.3% of tetrabutyl phosphonium iodide generated a yield of 14%. • Hydrophobic chains play an important role in the stability of devices. • 75% of performance was maintained by 200 h at 40% relative humidity. • In this study interactions interfacial were observed by theoretical calculations. Ionic liquids (ILs) are gradually becoming relevant within the efforts towards more stable perovskite solar cells, either by their incorporation into the perovskite active layer or as an interfacial additive. In this work, we synthesized the ionic liquid tetrabutylphosphonium iodide and applied it as an additive at the interface between the electron selective contact – mesoporous – TiO 2 and the perovskite CH 3 NH 3 PbI 3 active layer. Specific conditions of tetrabutylphosphonium iodide (B 4 PI) interfacial modification resulted in an improved device stability and a reduction of the hysteretic behavior suggesting a possible passivation of trap states and/or mitigation of ionic migration phenomena. [ABSTRACT FROM AUTHOR]

Carrier density of electrodeposited methylammonium lead iodide perovskite (CH 3 NH 3 PbI 3) can be modulated inside the 1017 to 1020 cm−3 range by carefully selecting the experimental parameters used during the last two chemical conversion steps of their synthesis. This finding has been made possible by performing systematically Mott-Schottky (MS) plots in aqueous solution on various semi-conducting CH 3 NH 3 PbI 3 perovskite samples. These latter were produced by a three-step synthesis method combining an electrodeposition step with two consecutive chemical conversion steps. In a first step, the galvanostatic electrodeposition of a lead dioxide (PbO 2) thin film is carried out. This latter is then converted into lead (II) iodide (PbI 2) by immersion in a HI/ethanol solution, this latter being then itself turned in a third and last step into the well-known CH 3 NH 3 PbI 3 perovskite by a new immersion step in a methylammonium iodide (MAI)/isopropanol solution. This very simple and highly reproducible synthesis method allows the production of perovskite thin films on large surfaces, unlike many other synthesis methods of perovskite thin films. In parallel to the determination of p-type character, carrier concentration and flat band potential of the perovskite samples using Mott-Schottky plots, their chemical composition, their morphology and their crystallinity were characterized by using scanning electron microscopy (SEM) and X-Ray Diffraction (XRD) and compared with those of the products obtained at the end of each of the two first steps, i.e. PbO 2 and PbI 2 respectively. Interestingly, it was shown that the final product is not always a pure p-type perovskite thin film as various amounts of lead (II) iodide (PbI 2) can be detected depending on the experimental parameters used during the two consecutive chemical conversion steps. The main result of this study is that the dopant concentration of perovskite thin films was shown to be inversely proportional to the amount of the remaining PbI 2 impurities detected in the bulk of perovskite thin films. • CH 3 NH 3 PbI 3 perovskite thin films were synthesized using electrodeposition and two chemical conversion steps. • They are p-type semiconductors with a bandgap energy close to 1.57 eV. • They all contain a PbI 2 fraction that depends on the two immersion durations. • When the PbI 2 % decreases, the carrier concentration increases over three decades. • Our synthesis method is promising for the fast and large scale production of tunable perovskites. [ABSTRACT FROM AUTHOR]

The degradation of the herbicide fenuron was investigated using a new porous bifunctional electrode where the electrooxidation takes place on one side and the photocatalysis on the other side. The characterization of the synthetized bifunctional electrode (PbO 2 /SnO 2 -Sb 2 O 3 /Ti//Ti/TiO 2 ) was performed by scanning electron microscopy, energy dispersive X-ray spectrometry and X-ray diffraction analysis and showed that the anodic side (Ti/SnO 2 -Sb 2 O 3 /PbO 2 ) is covered with a tetragonal β-PbO 2 film and that the photocatalytic side (Ti/TiO 2 ) consists of an anatase phase of TiO 2 . The single application of electrooxidation achieved 87.8% fenuron degradation and 84.1% chemical oxygen demand (COD) removal while heterogeneous photocatalysis resulted in only 59.2% and 39.7% fenuron concentration decay and COD removal, respectively. On the other hand, the photocatalytically-assisted electrooxidation (photo-electrooxidation) performed on the bifunctional electrode provided higher performances of fenuron degradation (97.5%) and mineralization (97.4%). Investigation of operating parameters highlighted the positive effect of increase in current density. Conversely, an increase in fenuron concentration led to a decrease in degradation rate and COD removal. It was also found that the COD removal and mineralization efficiency are higher in a neutral medium. [ABSTRACT FROM AUTHOR]

The study presents a novel lead dioxide reduction process which combined with flue-gas desulfurization technology to recover lead from lead-paste in the spent lead-acid batteries. With three different reducing agents, i.e. hydrogen peroxide(H 2 O 2 ), sodium sulfite(Na 2 SO 3 ) and sodium bisulfite(NaHSO 3 ), reduction of lead dioxide(PbO 2 ) under the same condition were studied comparatively. Synthesizing each kind of factors, NaHSO 3 was selected as the optimum lead dioxide reducing agent, and sodium sulfate(Na 2 SO 4 ) was generated as by-product in the process. A regeneration process of NaHSO 3 combined with flue-gas desulfurization technology was studied by mechanism analysis and simulation study, Na 2 SO 4 reacted with calcium oxide(CaO) and sulfur dioxide(SO 2 ) from the exhausted gas to recycle NaHSO 3 . The new process presented in this study provides a practicable and clean method to recycle the lead from the used batteries. [ABSTRACT FROM AUTHOR]

In this work, PbO 2 electrodes were prepared by pulse reverse current (PRC) electrodeposition. The effect of different duty cycles was investigated, which confirms that PRC deposition is an effective technique to optimize PbO 2 electrodeposition. Surface morphologies and crystal structures of the PbO 2 electrodes were characterized, and the voltammetric study was conducted to elucidate their electrochemical behavior. PRC deposition markedly changed the crystal structural and morphologic features of the resulting PbO 2 electrodes, giving rise to the increased content of β phase and a rough surface morphology. High-performance liquid chromatography (HPLC) was employed to monitor the galvanostatic electrolysis of benzoic acid (BA) occurring over the PbO 2 electrodes. A pseudo first-order reaction was found to well fit these BA degradation reactions, and the highest degradation efficiency was observed for the PbO 2 electrode made from 95% duty cycle. Concurrently, main aromatic intermediates and carboxylic acids generated in the BA degradation were identified, and a probable pathway was proposed for the BA degradation course on the PbO 2 anode. [ABSTRACT FROM AUTHOR]

Present study proposed the preparation, characterization and application of cobalt (Co), neodymium (Nd), and cerium (Ce) modified lead (PbO 2 ) electrodes. Morphological and structural properties of as-prepared electrodes were determined by SEM, XRD, and XPS. Linear sweep voltammetry (LSV) and accelerated life test were used to determine the electrocatalytic activity and stability of as-prepared electrodes. Higher oxygen evolution potentials (OEP) and longer service life were used to confirm the maximum electrocatalytic activity of Nd and Ce PbO 2 electrodes. The electro-oxidation ability was examined with Acid Orange 7 (AO 7) treatments. Cyclic voltammetry (CV), UV–visible, and fluorescence spectrophotometric analysis of AO 7 treatment were confirmed that Nd and Ce PbO 2 have excellent oxidation ability, higher AO 7 removal efficiency and higher total organic carbon (TOC) with a good correlation of instantaneous current efficiency (ε inst ) and higher hydroxyl radical ( • OH) generation rate, respectively. The effect of removal parameters was optimized with Ce PbO 2 electrode. Results of AO 7 and TOC removal were reached up to 100% and 93.7%, respectively, after 180 min of electrolysis at the optimum condition of 0.2 M Na 2 SO 4 concentration, 100 mg L –1 initial dye concentration, solution pH 7.0 and 20 mA cm –2 applied current density. Reusability and safety test analysis were used to detect the best results of AO 7 degradation with Ce PbO 2 electrode. Mass spectroscopy and ion chromatography (IC) were used to detect the formation of intermediates by-products. Finally, based on the detection of reaction by-products, a plausible degradation pathway including radical reactions, ring opening and de-nitrification was proposed. [ABSTRACT FROM AUTHOR]

A hydrophobic networked PbO 2 electrode was deposited on mesh titanium substrate and utilized for the electrochemical elimination towards paracetamol drug. Three dimensional growth mechanism of PbO 2 layer provided more loading capacity of active materials and network structure greatly reduced the mass transfer for the electrochemical degradation. The active electrochemical surface area based on voltammetric charge quantity of networked PbO 2 electrode is about 2.1 times for traditional PbO 2 electrode while lower charge transfer resistance (6.78 Ω cm 2 ) could be achieved on networked PbO 2 electrode. The electrochemical incineration kinetics of paracetamol drug followed a pseudo first-order behavior and the corresponding rate constant were 0.354, 0.658 and 0.880 h −1 for traditional, networked PbO 2 and boron doped diamond electrode. Higher electrochemical elimination kinetics could be achieved on networked PbO 2 electrode and the performance can be equal to boron doped diamond electrode in result. Based on the quantification of reactive oxidants (hydroxyl radicals), the utilization rate of hydroxyl radicals could reach as high as 90% on networked PbO 2 electrode. The enhancement of excellent electrochemical oxidation capacity towards paracetamol drug was related to the properties of higher loading capacity, enhanced mass transfer and hydrophobic surface. The possible degradation mechanism and pathway of paracetamol on networked PbO 2 electrode were proposed in details accordingly based on the intermediate products. [ABSTRACT FROM AUTHOR]

The soluble lead flow battery (SLFB) is a promising energy storage system. In comparison to conventional flow batteries, the membrane-less and single-flow design of SLFBs is potentially much more economical to scale up for utility-scale applications. However, SLFB lifespan reported so far is less than 200 cycles under normal flow conditions. This study reports a method for significantly extending the cycle life and expanding capacity of SLFBs. By adding an adequate amount of sodium ethanoate to the electrolyte, lead dioxide (PbO 2 ) deposition stability is materially improved and shed PbO 2 particles are substantially reduced. Lifespan of ethanoate-added SLFBs is shown to extend by over 50%, and under optimal condition exceeds 500 cycles at over 65% energy efficiency. This improvement in SLFB performance is primarily attributed to the stabilization of both the electroplated PbO 2 layers and proton activity at the electrodeposit-electrolyte interphase. We demonstrate a novel and economical approach for advancing performance of membrane-less flow batteries that involve redox reactions associated with acidity variation and operate through electrodeposition. [ABSTRACT FROM AUTHOR]