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In light of environmental problems such as the depletion of hydrocarbon resources and global warming, the use of environment-friendly power production has become crucial nowadays. Hydrogen can serve as a globally friendly energy source because the byproduct of hydrogen combustion is only water. By a hydrothermal approach, we synthesized barium manganese oxide (BaMnO 3) embedded on reduced graphene oxide (rGO) as a competent electrocatalyst for OER. We utilized X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive x-rays (EDX), Brunauer Emmette Teller (BET) and Raman to determine the crystal structure, morphology, elemental composition, surface area and lattice phenomena of the fabricated rGO/BaMnO 3 nanocomposite. The BaMnO 3 agglomerated nanoparticles were incorporated into the mesoporous hollow carbon nanosheets to form amorphous textured embedded rGO/BaMnO 3. This enhanced the intrinsic reactivity of rGO/BaMnO 3 nanocomposite for the oxygen evolution reaction (OER) in addition to increasing the effective surface area of the electrolyte. The electrochemical outcomes demonstrate that synthesized nanocomposite exhibited an impressive Tafel slope (36 mV dec−1), lowest overpotential (202 mV) and remarkable stability over 35 h. Therefore, the fabricated nanocomposite displayed exceptional efficiency in OER process as well as for numerous other future applications. [Display omitted] • RGO/BaMnO 3 nanocomposite was fabricated via facile hydrothermal technique. • Various analytical techniques were conducted to evaluate the material's properties. • The developed material exhibit OER process, which can be initiated by applied electrocatalyst at 0.50 V vs RHE using 1.0 ssM KOH solution. • The rGO/BaMnO 3 nanocomposite exhibits the minimal overpotential (202 mV) with low Tafel slope (36 mV dec−1). • RGO decorated BaMnO 3 (rGO/BaMnO 3) exhibiting remarkable stability of 35 h tested via chronoamperometry. [ABSTRACT FROM AUTHOR]

Photoelectrochemical (PEC) performance of photoanode is limited by the cascade-dynamic processes, mainly including light absorption, charge separation, and surface reaction. This work adopted a strategy of nanocones modification on FTO substrate (FTO-NC) to enhance light utilization and photoelectrons collection for improved PEC water splitting. Comparative studies showed that FTO-NC enhanced the light scattering, promoting the conversion process of photon to electron/hole and enlarging the effective surface area of BiVO 4 for surface reaction. Meanwhile, cooperative Mo-doping and Co-MOF decoration improved the bulk electron transportation in BiVO 4 , hole migration towards the electrode surface, and accelerated the water oxidation reaction of photogenerated holes. The photocurrent density of FTO-NC/BiVO 4 -Mo/MOFs reached 3.56 mA cm−2, 6.14 times that of pristine BiVO 4. The IPCE of FTO-NC/BiVO 4 -Mo/MOFs photoanode achieve 60% at 1.23 V vs. RHE, demonstrating a significantly enhanced light utilization performance. This work presents new insight into boosting cascade-dynamic processes through collaborative strategies for highly efficient PEC water-splitting. [Display omitted] • FTO-NC had high light scattering effect for increasing light absorption of BiVO 4. • The photocurrent of FTO-NC/BiVO 4 -Mo/MOFs was increased by 6.14 times than FTO-BiVO 4. • FTO-NC/BiVO 4 -Mo/MOFs showed 2.7-times higher η transfer than FTO-BiVO 4. [ABSTRACT FROM AUTHOR]

The electrocatalytic performance of MoNi‐based nanomaterials undergo selenization has garnered significant interest due to their modified electronic structure, while still posses certain challenges for obtained bimetallic selenides. Here, a novel MoNi‐based electrocatalyst of NiMoO4@Mo15Se19/NiSe2 core‐shell nanomaterials is constructed to promote the desorption of OOH* which can facilitate the water oxidation process. NiMoO4@Mo15Se19/NiSe2 core‐shell nanoarrays show that the "cores" are mainly NiMoO4 nanorods while the "shells" are the bimetallic selenides nanoflakes, which are super architectures that can expand more active sites and accelerate the electron transfer. Moreover, the hybridization interaction between Ni 3d, Mo 4d, and Se 4p orbitals leads to an asymmetric distribution of electric clouds, which decreases the adsorption energy and transformation of oxygen‐containing species. Electrochemical data displays that the overpotentials of NiMoO4@Mo15Se19/NiSe2 core‐shell nanomaterials are only 195 mV, 220 mV, and 224 mV for oxygen evolution reaction (OER) in alkaline freshwater, alkaline simulated seawater, and alkaline natural seawater. The current density decay is negligible after 100 h stability at about 1.46 V with a three‐electrode system in alkaline natural seawater. The low cost and the unique MoNi‐based bimetallic selenides in this work provide a more constructive solution for designing efficient and stable OER catalysts in the future. [ABSTRACT FROM AUTHOR]

Developing cost‐efficient trifunctional catalysts capable of facilitating hydrogen evolution reaction (HER), oxygen evolution reaction (OER), and oxygen reduction reaction (ORR) activity is essential for the progression of energy devices. Engineering these catalysts to optimize their active sites and integrate them into a cohesive system presents a significant challenge. This study introduces a nanoflower (NFs)‐like carbon‐encapsulated FeNiPt nanoalloy catalyst (FeNiPt@C NFs), synthesized by substituting Co2+ ions with high‐spin Fe2+ ions in Hofmann‐type metal‐organic framework, followed by carbonization and pickling processes. The FeNiPt@C NFs catalyst, characterized by its nitrogen‐doped carbon‐encapsulated metal alloy structure and phase‐segregated FeNiPt alloy with slight surface oxidization, exhibits excellent trifunctional catalytic performance. This is evidenced by its activities in HER (−25 mV at 10 mA cm−2), ORR (half‐wave potential of 0.93 V), and OER (294 mV at 10 mA cm−2), with the enhanced water oxidation activity attributed to the high‐spin state of the Fe element. Consequently, the Zn‐air battery and anion exchange membrane water electrolyzer assembled by FeNiPt@C NFs catalyst demonstrate remarkable power density (168 mW cm−2) and industrial‐scale current density (698 mA cm−2 at 1.85 V), respectively. This innovative integration of multifunctional catalytic sites paves the way for the advancement of sustainable energy systems. [ABSTRACT FROM AUTHOR]

The development of high‐performance photocatalytic systems for CO2 reduction is appealing to address energy and environmental issues, while it is challenging to avoid using toxic metals and organic sacrificial reagents. We here immobilize a family of cobalt phthalocyanine catalysts on Pb‐free halide perovskite Cs2AgBiBr6 nanosheets with delicate control on the anchors of the cobalt catalysts. Among them, the molecular hybrid photocatalyst assembled by carboxyl anchors achieves the optimal performance with an electron consumption rate of 300±13 μmol g−1 h−1 for visible‐light‐driven CO2‐to‐CO conversion coupled with water oxidation to O2, over 8 times of the unmodified Cs2AgBiBr6 (36±8 μmol g−1 h−1), also far surpassing the documented systems (<150 μmol g−1 h−1). Besides the improved intrinsic activity, electrochemical, computational, ex‐/in situ X‐ray photoelectron and X‐ray absorption spectroscopic results indicate that the electrons photogenerated at the Bi atoms of Cs2AgBiBr6 can be directionally transferred to the cobalt catalyst via the carboxyl anchors which strongly bind to the Bi atoms, substantially facilitating the interfacial electron transfer kinetics and thereby the photocatalysis. [ABSTRACT FROM AUTHOR]

The catalytic oxidation of water and C(sp3)−H bonds enables the conversion of solar/electrochemical energy into chemical energy and alcohol fuel production, respectively, and therefore plays important roles in energy conversion/storage. These transformations are typically catalyzed by the highly active complexes of the earth‐abundant first‐row transition metals (Mn, Fe, Co, Ni, and Cu) with tetra‐amido macrocyclic ligands (TAMLs), although the related kinetics and thermodynamics remain underexplored. This review uses free energy relationships between kinetic and thermodynamic descriptors as normalized metrics to benchmark/compare these TAML‐based catalysts and assess the advances in their development. [ABSTRACT FROM AUTHOR]

We report two dinuclear rhenium(V) oxo complexes 1 and 2 types, [ReV(O)(Cl)3(L2−)ReV(O)(Cl)3][NBu4]2 (1, L2− = dianionic 2,5-dihydroxy 1,4-benzoquinone (DBQ2−)) and (2, L2− = dianionic chloranilic acid (CA2−) ligands), as a homogeneous electrocatalyst for water oxidation reactions in the acetonitrile–water mixture. The evolution of dioxygen gas at the anode was confirmed by a GC-TCD study. In controlled potential electrolysis (CPE), oxidation at 1.30 V (vs. Ag/AgCl) at neutral pH, 1 and 2 afforded 1+ [ReVI(O)(Cl)3(DBQ˙3−)ReVI(O)(Cl)3]− and 2+ [ReVI(O)(Cl)3(CA˙3−)ReVI(O)(Cl)3]− ions, respectively, via the redox induced electron transfer (RIET) process. Electrochemically generated species of 1+ and 2+ could be isolated in dry acetonitrile. 1+ and 2+ ions give strong EPR signals in fluid solution as well as under frozen glass conditions due to the [ReVI(O)(Cl)3(L˙3−)ReVI(O)(Cl)3]− ↔ [ReVI(O)(Cl)3(L2−)ReV(O)(Cl)3]− (where L2− = DBQ2− and CA2−) equilibrium. However, the continuation of the CPE study (1.30 V vs. Ag/AgCl) in the presence of acetonitrile–water mixture oxidised the in situ generated species of 1+ and 2+ to higher valent ReVI＝O species. These species (1+ and 2+) bound water through the water nucleophilic attack (WNA) to produce peroxide intermediate species of [ReV(OOH)(Cl)3(DBQ2−)ReV(OOH)(Cl)3] (A1) and [ReV(OOH)(Cl)3(CA2−)ReV(OOH)(Cl)3] (A2) for catalysts 1 and 2, respectively. Interestingly, A1 and A2 were authenticated and analysed by ESI mass spectrometry and infrared spectroscopy and were the active precursors of this water oxidation process. The extent of current generation under similar conditions suggested that complex 1 is superior to complex 2 for the water oxidation reaction. Notably, the maximum turnover frequency (TOFmax) of catalysts 1 and 2 were 2.1 and 1.6 s−1 at 0.27 V and 0.24 V over potential, respectively, which is very significant in WOR. [ABSTRACT FROM AUTHOR]

Highly efficient and stable catalysts for oxygen evolution reaction (OER) are urgently needed for water splitting. Here, a novel FeNiMnCuAl LDH catalyst decorated with Ag nanoparticles for OER was fabricated by the hydrothermal and chemical reduction method. The heterostructure catalyst exhibits a low over potential of 208 mV to achieve a current density of 10 mA cm−2 and a low Tafel slope of 60 mV dec−1. In addition, it has an excellent long-term stability for more than 50 h at a large current density of ∼100 mA cm−2. By combining the experiment and theoretical calculation, it shows that the increased conductivity and optimized energy barrier are responsible for the boosted intrinsic activity. This work not only provides a promising electrocatalyst but also broadens the application field of high-entropy materials. • A novel high-entropy heterostructure catalyst of Ag-FeNiMnCuAl LDH is reported. • Ag-FeNiMnCuAl LDH exhibits excellent OER activity (208 mV@10 mA cm−2). • The catalyst has an excellent stability for more than 50 h at ∼100 mA cm−2. • XPS analysis demonstrates the electronic interaction at the heterostructure interface. • An atomic-scale insight into the structure-property relation is revealed by DFT. [ABSTRACT FROM AUTHOR]

Photosynthetic hydrogen induced by Chlamydomonas reinhardtii presents a promising pathway for producing clean and renewable biofuel. Whereas, this process is transient owing to the repression of [FeFe]-hydrogenase by the oxygen co-evolved in photosystem II. Pulsed light is employed to prevent O 2 accumulation and the activation of Calvin-Benson-Bassham cycle for sustainable H 2. While light quality significantly influences photosynthesis, the optimal wavelength for pulsed light-induced H 2 production remains not fully elucidated. Continuous irradiation at 660–670 nm performs poorly in H 2 production due to the activation of PSII, which is responsible for water oxidation. However, in this study, O 2 was removed using a combination of pulsed light and sulfite treatment. Among six light regimes with different wavelengths, pulsed light peaking at 660 nm resulted in the highest photo-H 2 evolution, reaching approximately 180 mL L−1 within three days. This value was 1.4 times higher than that achieved under conventionally white pulsed light. Exposure to 660 nm red pulsed light not only sustained high activity of PSII and hydrogenase but also reduced the gene expression levels of ribulose-1,5-bisphosphate carboxylase/oxygenase and ferredoxin-NADP+ reductase, which was supposed to attenuate the competing effects of CBB cycle. This finding optimizes an efficient light source for pulsed light-induced H 2 production and demonstrates a great potential for refining pulsed light parameters to improve H 2 production in algae in the future. [Display omitted] • The effects of pulsed light wavelengths on H 2 photoproduction were investigated. • Red pulsed light at 660 nm exhibits the highest level of H 2 photoproduction ability. • Red pulsed light at 660 nm maintains the high activity of both PSII and H 2 ase. • Red pulsed light at 660 nm suppresses the activity of CBB cycle. [ABSTRACT FROM AUTHOR]

This paper introduces a facile method to develop core-shell nanocomposite Cu/(Cu 2 O/CuO) through gradually oxidation on Cu nanocomposite precursors. As-prepared catalyst exhibited excellent catalytic activity in the reaction of water oxidation reaction (WOR). Comparing with the reported catalyst, Cu/(Cu 2 O/CuO) posed one of the highest O 2 evolution around 7700 μmol g-1·h-1. By analyzing the composition of catalysts in each reaction stages, the evolution pathway of Cu towards Cu 2 O/CuO and the different roles of each component in catalytic water oxidation reactions were deeply studied. In presence of high conductive Cu element and excellent light absorption Cu 2 O, the photo generated electron and holes can be effectively separated and greatly improve the efficiency of the catalyst. The evolution process and synergistic effects of the three components play a crucial role in improving photocatalytic efficiency, which promoting the nanocomposite to be a highly efficient core-shell catalyst for WOR. This paper presents the evolution of a highly active photocatalytic water oxidation catalyst with no photosensitizers. [Display omitted] • Cu/(Cu 2 O/CuO) core-shell nanocomposite exhibits a a high oxygen production rate of 7700 μmol·g-1·h-1. • The relationship between the evolution of Cu to Cu 2 O/CuO and the photocatalytic efficiency was explored. • Cu/Cu 2 O core-shell plays a crucial role in charge separation and dramatically increasing the catalytic efficiency. [ABSTRACT FROM AUTHOR]

A special membrane electrode assembly to measure operando X‐ray absorption spectra and resonant photoemission spectra of mesoporous templated iridium oxide films is used. These films are calcined to different temperatures to mediate the catalyst activity. By combining operando resonant photoemission measurements of different films with ab initio simulations these are able to unambiguously distinguish µ2‐O (bridging oxygen) and µ1‐O (terminal oxygen) in the near‐surface regions of the catalysts. The intrinsic activity of iridium oxide scales with the formation of µ1‐O (terminal oxygen) is found. Importantly, it is shown that the peroxo species do not accumulate under reaction conditions. Rather, the formation of µ1‐O species, which are active in O−O bond formation during the OER, is the most oxidized oxygen species observed, which is consistent with an O−O rate‐limiting step. Thus, the oxygen species taking part in the electrochemical oxidation of water on iridium electrodes are more involved and complex than previously stated. This result highlights the importance of employing theory together with true and complementary operando measurements capable of probing different aspects of catalysts surfaces during operation. [ABSTRACT FROM AUTHOR]

A new cooperative photoredox catalytic system, [RuII(trpy)(bpy)(H2O)][3,3′-Co(8,9,12-Cl3-1,2-C2B9H8)2]2, 5, has been synthesized and fully characterized for the first time. In this system, the photoredox catalyst [3,3′-Co(8,9,12-Cl3-1,2-C2B9H8)2]− [Cl6-1]−, a metallacarborane, and the oxidation catalyst [RuII(trpy)(bpy)(H2O)]2+, 2 are linked by non-covalent interactions. This compound, along with the one previously synthesized by us, [RuII(trpy)(bpy)(H2O)][(3,3′-Co(1,2-C2B9H11)2]2, 4, are the only examples of cooperative molecular photocatalysts in which the catalyst and photosensitizer are not linked by covalent bonds. Both cooperative systems have proven to be efficient photocatalysts for the oxidation of alkenes in water through Proton Coupled Electron Transfer processes (PCETs). Using 0.05 mol% of catalyst 4, total conversion values were achieved after 15 min with moderate selectivity for the corresponding epoxides, which decreases with reaction time, along with the TON values. However, with 0.005 mol% of catalyst, the conversion values are lower, but the selectivity and TON values are higher. This occurs simultaneously with an increase in the amount of the corresponding diol for most of the substrates studied. Photocatalyst 4 acts as a photocatalyst in both the epoxidation of alkenes and their hydroxylation in aqueous medium. The hybrid system 5 shows generally higher conversion values at low loads compared to those obtained with 4 for most of the substrates studied. However, the selectivity values for the corresponding epoxides are lower even after 15 min of reaction. This is likely due to the enhanced oxidizing capacity of CoIV in catalyst 5, resulting from the presence of more electron-withdrawing substituents on the metallacarborane platform. [ABSTRACT FROM AUTHOR]

Herein, we report two autologous phosphates for electrocatalytic water oxidation. Although they have many similarities, the four-coordinated Co sites in Co3(PO4)2 showed higher activity than the six-coordinated Co sites in Co3(OH)2(HPO4)2. This was because the four-coordination CoII possessed a high turnover frequency and could be easily transformed into high-valent active cobalt (hydr)oxide species. [ABSTRACT FROM AUTHOR]

The oxygen evolution reaction (OER) is a crucial energy-storing and energy-changing half-process in water splitting. It is critical to expand the availability of renewable energy reservoirs, and effective electrodes must be robust and possess a high level of catalytic activity. However, it is difficult to eliminate overpotential and improve the performance of OER. In this study, Erbium (Er)-doped samarium oxide (Sm 2 O 3) was synthesized by a facile co-precipitation technique. Using X-ray diffraction analysis, it was determined that a Sm 2 O 3 cubic structure was formed when sharp peaks were observed. Using Fourier-transform infrared (FTIR spectroscopy) and scanning electron spectroscopy (SEM) pictures, the existence of Sm 2 O 3 crystals was detected and surface geometry was observed. Energy dispersive X-ray (EDX) and X-ray photoelectron spectroscopy (XPS) confirm the successful Er doping in Sm 2 O 3. The OER activities of pure Sm 2 O 3 and Sm 2 O 3 coupled with Er were determined using electrochemical. In comparison to pure Sm 2 O 3 , a high amount of Er-doped Sm 2 O 3 possessed a low overpotential (365 mV for the OER) and a small Tafel slope (47 mV/dec). Consequently, OER became extremely active, metal oxide's structure and catalytic capabilities were altered by inclusion of rare earth metals. Erbium is an essential component when doped in Sm 2 O 3 that improves the performance of OER. Among all 2% Er doped Sm 2 O 3 is an excellent material for energy conversion. [ABSTRACT FROM AUTHOR]

For an efficient hydrogen production, electrochemical ethanol oxidation is a great alternative to the oxygen evolution reaction (OER) due to the generation of value‐added products. In this electrosynthetic contribution, the properties of ethanol oxidation are investigated with regard to the influence of pH, temperature and potential using RuO2‐based catalysts. Results show acetic acid as main reaction product with yields of up to 29 % and Faraday efficiencies of ≥71 %. Increasing the potential marginally from 1.40 V vs. RHE to 1.45 V vs. RHE promoted parasitic OER and, therefore, yield (≥10 %) and Faraday efficiency (≥56 %) of the organic products decreased. Doping RuO2 electrodes with TiO2 shows promising results in suppressing OER during ethanol oxidation. Additionally, the catalyst allows moderate OER potentials in water electrolysis, making the catalyst a switchable material. [ABSTRACT FROM AUTHOR]

Constructing heterostructural photoanodes is attractive for elevating the photoelectrochemical (PEC) performance, however, it is a long‐standing challenge to achieve highly efficient interfacial charge transfer. Herein, a CoFe metal‐thiolate framework (CoFe MTF)/Fe2O3 photoanode connected by an interfacial Fe─O─N/S bond is designed to modulate the behavior of charge carriers and improve water oxidation performance. It is disclosed that this interfacial bond functions as a direct charge transfer bridge between shallow trap states of Fe2O3 and CoFe MTF, leading to prolonged carrier recombination lifetimes (85 ns for CoFe MTF/Fe2O3 compared to 37 ns for Fe2O3) and enhanced charge transfer efficiency. Alternatively, a robust interfacial electric field is established in the CoFe MTF/Fe2O3 p–n heterojunction, facilitating efficient charge transfer. As expected, the CoFe MTF/Fe2O3 photoanode exhibits significant enhancement in water oxidation, resulting in a three‐fold increase in photocurrent density compared to pristine Fe2O3. This study highlights the significance of designing interfacially bonded heterostructural photoelectrodes to regulate the transfer characters of charge carriers. [ABSTRACT FROM AUTHOR]

Heteroatom doping can tune the band structure of semiconductors and enhance their carrier transfer capacity for improving the performance of photoelectrochemical water oxidation. Nevertheless, the introduction of dopants is not always beneficial. In this study, magnesium (Mg) is adopted to dope ZnIn2S4 nanosheet array photoanodes to form a type‐II band structure and reduce bulk recombination, but concurrently introduced deleterious oxygen (O) defects slow down the surface catalytic reaction kinetics. Furthermore, a facile heat treatment strategy is proposed to transform these O defects into Mg─O bonds. First‐principles calculations and electrochemical characterization indicate that the presence of Mg─O bonds provides abundant active sites and efficiently accelerates the surface oxygen evolution reaction by precisely realigning the rate‐determining step from OH* to O* (step 2) to OOH* to O2 (step 4), thereby retarding charge trapping and recombination. As a result, such a photoanode achieves a remarkable performance with a photocurrent as high as 4.91 mA cm−2 at 1.23 V versus reversible hydrogen electrode, and the onset potential shifts negatively about 340 mV. This work provides a new defect modulation idea for converting detrimental defects to favorable ones, and it can be expected to have wide applications in the fields of energy, catalysis, and optoelectronics, etc. [ABSTRACT FROM AUTHOR]

Paired electrolysis offers an auspicious strategy for the generation of high‐value chemicals, at both the anode and cathode, in an integrated electrochemical reactor. Through efficient electron utilization, routine product misuse at overlooked electrodes can be prevented. Here, an original paired electrosynthetic system is reported that can convert CO2 to ethylene (C2H4) at the cathode, and water to hydrogen peroxide (H2O2) at the anode under a single pass of electric charge. Amongst various investigated copper (Cu) nanomorphologies, the bespoke mixed Cu nanowire/nanoparticle catalyst recorded a peak C2H4 Faraday efficiency (FE) of 60% following 370 h of electrolysis at 200 mA cm−2, while the tailored boron‐doped diamond (BDD) anode accumulated an unprecedented ≈1% w/w of H2O2 in 4 m K2CO3 upon applying 300 mA cm−2 for 10 h. When paired, the dual C2H4‐H2O2 electrochemical cell attains a combined FE of 120% for 50 h at 200 mA cm−2, a combined energy efficiency (EE) of 69%, and a 50% decrease in the overall electrical energy consumption (EEC) compared to the individual electrosynthesis of C2H4 and H2O2. [ABSTRACT FROM AUTHOR]

Improving activity and stability of Ruthenium (Ru)-based catalysts in acidic environments is eager to replace more expensive Iridium (Ir)-based materials as practical anode catalyst for proton-exchange membrane water electrolyzers (PEMWEs). Here, a bicontinuous nanoreactor composed of multiscale defective RuO2 nanomonomers (MD-RuO2-BN) is conceived and confirmed by three-dimensional tomograph reconstruction technology. The unique bicontinuous nanoreactor structure provides abundant active sites and rapid mass transfer capability through a cavity confinement effect. Besides, existing vacancies and grain boundaries endow MD-RuO2-BN with generous low-coordination Ru atoms and weakened Ru-O interaction, inhibiting the oxidation of lattice oxygen and dissolution of high-valence Ru. Consequently, in acidic media, the electron- and micro-structure synchronously optimized MD-RuO2-BN achieves hyper water oxidation activity (196 mV @ 10 mA cm−2) and an ultralow degradation rate of 1.2 mV h−1. A homemade PEMWE using MD-RuO2-BN as anode also conveys high water splitting performance (1.64 V @ 1 A cm−2). Theoretical calculations and in-situ Raman spectra further unveil the electronic structure of MD-RuO2-BN and the mechanism of water oxidation processes, rationalizing the enhanced performance by the synergistic effect of multiscale defects and protected active Ru sites. Developing stable water oxidation catalysts is of great importance for proton-exchange membrane water electrolyzers. Here the authors report a bicontinuous nanoreactor composed of multiscale defected RuO2 nanocrystals for robust acidic water oxidation reactivity. [ABSTRACT FROM AUTHOR]

Water oxidation on magnetic catalysts has generated significant interest due to the spin-polarization effect. Recent studies have revealed that the disappearance of magnetic domain wall upon magnetization is responsible for the observed oxygen evolution reaction (OER) enhancement. However, an atomic picture of the reaction pathway remains unclear, i.e., which reaction pathway benefits most from spin-polarization, the adsorbent evolution mechanism, the intermolecular mechanism (I2M), the lattice oxygen-mediated one, or more? Here, using three model catalysts with distinguished atomic chemistries of active sites, we are able to reveal the atomic-level mechanism. We found that spin-polarized OER mainly occurs at interconnected active sites, which favors direct coupling of neighboring ligand oxygens (I2M). Furthermore, our study reveals the crucial role of lattice oxygen participation in spin-polarized OER, significantly facilitating the coupling kinetics of neighboring oxygen radicals at active sites. [ABSTRACT FROM AUTHOR]

α‐Fe2O3 with suitable band structure, good chemical stability, and easy preparation, is a potential photoanode material. However, the key to enhance the performance of α‐Fe2O3 photoanode is to improve the transport characteristics of bulk carriers. It is expected to form a Schottky barrier to improve the carrier separation efficiency by embedding metal nanoparticles into the matrix, but the process is still challenging. Herein, a strategy of forming the Schottky barrier is shown to improve bulk carrier transport dynamics by embedding laser‐generated Pt nanocrystals in α‐Fe2O3 photoanode, which achieves photocurrent densities of up to 1.16 mA cm−2 at 1.23 VRHE (from original 0.21 mA cm−2). This work provides another way to promote the carrier transfer and separation of α‐Fe2O3, which is of great significance to improve the photoelectrochemical water splitting performance. [ABSTRACT FROM AUTHOR]

Bismuth vanadate (BiVO4) is reported as a key material in photoelectrocatalysis owing to high theoretical efficiency, relatively narrow band gap of 2.4 eV, and favorable conduction band edge position for hydrogen evolution. However, the sluggish hole transport dynamics lead to slow photogenerated charge separation and transport efficiencies, which result in charge recombination due to aggregation. Herein, a novel hole transport layer of copper(I) thiocyanate (CuSCN) with the aim of significantly enhancing the efficiency of charge transport and stability of BiVO4 photoanodes is reported. The introduction of the hole transport layer could provide an appropriate intermediate energy level for photogenerated hole transfer and avoid charge recombination and trapping. After a photoassisted electrodeposition process of NiCoFe‐Bi catalysis, the obtained photoanode achieves a photocurrent density of 5.6 mA cm−2 at 1.23 V versus reversible hydrogen electrode under AM 1.5 G simulated solar radiation, and an applied bias photon to current efficiency of 2.31%. With the CuSCN layer, BiVO4 photoanode presented impressive stable photocurrent during 50 h continuous illumination. Meanwhile, the unbiased tandem device of the NiCoFe‐Bi/CuSCN/BiVO4 photoanode and the Si solar cell exhibit a solar‐to‐hydrogen efficiency of 5.75% and excellent stability for 14 h. [ABSTRACT FROM AUTHOR]

We report on the first peptoid‐based catalyst for visible light driven water oxidation, the complex TPT2Co. Peptoids are N‐substituted glycine oligomers, and TPT is a peptoid trimer incorporating terpyridine ligand, an ethanolic group as a proton acceptor and a non‐catalytic benzyl group. We explored the ability of TPT2Co to perform as a catalyst for water oxidation in phosphate buffer at pH 9.5, in the presence of the photosensitizer [Ru(bpy)3]2+ and the sacrificial electron acceptor Na2S2O8. We demonstrated that TPT2Co can catalyze water oxidation by a blue LED with an intensity of only 1.5 mW/cm2 towards oxygen production at pH 9.5 with a maximal TON of 28.1 in 45 min. The stability of TPT2Co during the light‐driven water oxidation as well as its ability to stabilize the photosensitizer were confirmed by a combination of UV‐Vis, IR and ESI‐MS analysis. [ABSTRACT FROM AUTHOR]

[Display omitted] • High-valence Mo atoms embedded in FeNi (oxy)hydroxides are realized by boronation. • MoFeNi ultrathin nanoflakes promote mass diffusion and electron transfer for OER. • Mo can modulate electronic structure and optimize intermediates adsorption energy. • AEM electrolyser produce hydrogen continuously for several hours at 500 mA cm−2. The incorporation of high-valence transition metal atoms into FeNi (oxy)hydroxides may be a promising strategy to regulate the intrinsic electronic states, thereby reducing the thermodynamic barrier and accelerating oxygen evolution reaction (OER). Here, a high-valence Mo atoms doping route is proposed by an efficient self-reconstruction strategy to prepare MoFeNi (oxy)hydroxides for efficient alkaline OER. By using borides (MoNiB) as sacrificial template and Mo source, FeNi (oxy)hydroxides nanoflakes embedded with high-valence Mo atoms (MoFeNi) is successfully synthesized, which can modulate the electron coordination to improve the intrinsic catalytic activity. Remarkably, the obtained MoFeNi exhibits extremely low overpotential (η 100 = 252 mV and η 500 = 288 mV) and small Tafel slope (18.35 mV dec-1). The robust catalyst can run stably for hours at 500 mA cm−2. Characterization results and theoretical calculations confirmed that the addition of high-valence Mo effectively modulated the intrinsic electronic structure of metal sites and optimized the adsorption/desorption energy of the intermediates, accelerating OER reactions kinetics. By coupling MoFeNi anode with Pt/C cathode, anion exchange membrane (AEM) electrolyser can operate stably at 500 mA cm−2 with about less than 2.2 V. This research introduces a novel approach to develop ideal electrocatalysts through the incorporation of high-valence molybdenum species. [ABSTRACT FROM AUTHOR]

The sluggish kinetics of the oxygen evolution reaction (OER) is generally undesirable for advanced green hydrogen production through renewable energy unless the employment of efficient catalysts. Perovskite-type oxide materials have been recognized as promising alternatives to overcome the kinetic limitations of OER. Nonetheless, despite extensive research endeavors, the electrochemical activity and durability of versatile perovskite candidates still fall short of expectations. Herein, a novel perovskite cobaltite BaCo 0.6 Fe 0.2 W 0.2 O 3-δ (BCFW0.2), enlightened by tungsten incorporation strategy, is proposed as a reliable electrocatalyst for OER. Characterization analyses unravel that the manipulation of tungsten substitution in BCFW0.2 leads to the formation of high-symmetry crystal structure and more reactive oxygen species, which in turn promotes favorable oxygen catalytic behavior. Accordingly, the BCFW0.2 catalyst exhibits significantly lower overpotential of 273 mV at a current density of 10 mA cm−2 and remarkably smaller Tafel slope of 42.34 mV dec−1 relative to its un-doped counterpart, as well as considerable operational durability under various current densities. The mechanism of lattice oxygen activation in BCFW0.2 is also explored. This study paves a constructive avenue for the rational design of high-performance perovskite-based derivative catalysts. [Display omitted] • A novel single-hexagonal perovskite electrocatalyst BaCo 0.6 Fe 0.2 W 0.2 O 3-δ (BCFW0.2) is well-developed. • Tungsten substitution contributes to formation of high-symmetry crystal structure and more reactive oxygen species. • BCFW0.2 achieves exceptional activity and durability for water oxidation, significantly surpassing pristine BCF counterpart. • Oxygen evolution mechanism of BCFW0.2 is probably associated with the LOM pathway. [ABSTRACT FROM AUTHOR]

Among the most active oxygen evolution reaction (OER) catalysts, mixed metal oxides based on Ni, Fe, and Co metals are recognized as economical yet excellent replacements for RuO2 and IrOx. However, tuning and searching for optimal compositions of multi–element–compound electrocatalysts is a big challenge in catalysis research. Conventional materials screening experiments and theoretical simulations are labor–intensive and time–consuming. Machine learning offers a promising paradigm for accelerating electrocatalyst research and simultaneously understanding composition–activity correlation. Herein, we introduce an Explainable AI (XAI) framework for predicting the electrocatalytic performance of OER catalysts. By integrating the robust Random Forest (RF) model for machine learning with the Shapley Additive Explanations (SHAP) method for model explanation, we achieved accurate predictions of the overpotential for various compositions of (Ni−Fe−Co−Ce)Ox catalysts (R2=0.8221). More importantly, we obtained valuable insights into how each metal and their interactions influence the overpotential of the catalysts. Our results highlight the versatility of the RF model with SHAP in identifying the optimal composition of (Ni−Fe−Co−Ce)Ox catalysts for electrocatalytic oxygen evolution, showing its potential applicability across various catalyst synthesis methods. Finally, we anticipate that this work will lead to exciting possibilities in designing highly active multi–element compound electrocatalysts with the aid of explainable AI. [ABSTRACT FROM AUTHOR]

Developing ruthenium‐based heterogeneous catalysts with an efficient and stable interface is essential for enhanced acidic oxygen evolution reaction (OER). Herein, we report a defect‐rich ultrathin boron nitride nanosheet support with relatively independent electron donor and acceptor sites, which serves as an electron reservoir and receiving station for RuO2, realizing the rapid supply and reception of electrons. Through precisely controlling the reaction interface, a low OER overpotential of only 180 mV (at 10 mA cm−2) and long‐term operational stability (350 h) are achieved, suggesting potential practical applications. In situ characterization and theoretical calculations have validated the existence of a localized electronic recycling between RuO2 and ultrathin BN nanosheets (BNNS). The electron‐rich Ru sites accelerate the adsorption of water molecules and the dissociation of intermediates, while the interconnection between the O‐terminal and B‐terminal edge establishes electronic back‐donation, effectively suppressing the over‐oxidation of lattice oxygen. This study provides a new perspective for constructing a stable and highly active catalytic interface. [ABSTRACT FROM AUTHOR]

This article presents the development of efficient catalysts for electrocatalytic water oxidation by synthesizing CoNi-LDH/HNT (cobalt–nickel layered double hydroxide/halloysite nanotube) binary composites. Four novel CoNi-LDH/HNT nanocomposites were fabricated on nickel foam substrates by electrodepositing CoNi-LDH nanostructures onto HNT-modified nickel foam. The electrocatalytic activities of these nanocomposites were evaluated in the alkaline oxygen evolution reaction (OER). Incorporating HNTs as a support material significantly enhanced the performance of pristine CoNi-LDH in the OER. Through the manipulation of the Co/Ni molar ratio in the LDH, a nanocomposite with optimal performance was achieved (denoted as CoNi/H-2). This nanocomposite demonstrated superior electrocatalytic activity in the alkaline OER. Specifically, it exhibited an overpotential of 183 mV (at 10 mA cm−2) and a Tafel slope of 68.2 mV decade−1. CoNi/H-2 also showed robust electrochemical stability over 24 hours under harsh OER conditions, maintaining a current density of 53 mA cm−2, while experiencing minimal activity loss. Significantly, the nanocomposite yielded an impressive current density of 475 mA cm−2 with an overpotential of only 308 mV. This study underscores the potential of HNTs as a cost-effective and abundant material for designing efficient catalysts for OER. [ABSTRACT FROM AUTHOR]

Perovskites have become promising alternatives to precious metal-catalyzed oxygen evolution reaction (OER). Herein, we report the synthesis of several perovskite nanofibers, specifically La 0.6 Sr 0.4 Co x Ni 1- x O 3- δ (LSCN), and investigate their electrocatalytic water oxidation activity in alkaline electrolytes. La 0.6 Sr 0.4 Co 0.8 Ni 0.2 O 3- δ (LSCN-0.8) is selected and immersed in an aqueous NaBH 4 solution for 1 h for surface reconstruction. The perovskite nanofibers' electrocatalytic OER activity and stability are rigorously evaluated using a standard three-electrode system. Results reveal that even a slight Co substitution for Ni content within the LSCN perovskite structure has a notable impact on electrocatalytic activity. Moreover, LSCN-0.8 exhibits an overpotential of 363 mV at 20 mA cm−2 in 1 M KOH. However, significant improvement is observed after the surface reconstruction process. The optimized LSCN-0.8 (now called LSCN-2) displays the lowest OER overpotential (320 mV) under the same conditions. Furthermore, the LSCN-2 nanostructure demonstrates exceptional electrode stability, as evidenced by only a slight decrease in electrocatalytic performance during 5000 cycles of linear sweep voltammetry. [ABSTRACT FROM AUTHOR]

The document is a contents list for the journal "Chemical Communications" published in 2024. It includes a range of articles on various topics such as cross-coupling of alcohols, the structure of CO2 in silica adsorbents, transdermal delivery of insulin, and the design of Zn2+ complexes for chemo-selective hetero-coupling of alcohols. The journal is published by The Royal Society of Chemistry, a leading chemistry community. The document also mentions approved training courses offered by the society. [Extracted from the article]

N-doped NiFe(B) (oxy)hydroxide can promote the catalytic activity for an alkaline oxygen evolution reaction (OER) significantly, but fabrication is difficult. Herein, we introduced a B-induction route to the N-NiFe(B) (oxy)hydroxide monolithic electrode under a relatively low temperature. We observed an excellent catalytic performance benefiting from an optimal electronic structure, enlarged surface area and improved hydrophilicity. Moreover, this mild protocol could be extended to fabricate an S-doped NiFe-based catalyst. This research could aid large-scale manufacture. [ABSTRACT FROM AUTHOR]

Electrosynthesis of H2O2 via both pathways of anodic two-electron water oxidation reaction (2e-WOR) and cathodic two-electron oxygen reduction reaction (2e-ORR) in a diaphragm-free bath can not only improve the generation rate and Faraday efficiency (FE), but also simplify the structure of the electrolysis bath and reduce the energy consumption. The factors that may affect the efficiency of H2O2 generation in coupled electrolytic systems have been systematically investigated. A piece of fluorine-doped tin oxide (FTO) electrode was used as the anode, and in this study, its catalytic performance for 2e-WOR in Na2CO3/NaHCO3 and NaOH solutions was compared. Based on kinetic views, the generation rate of H2O2 via 2e-WOR, the self-decomposition, and the oxidative decomposition rate of the generated H2O2 during electrolysis in carbonate electrolytes were investigated. Furthermore, by choosing polyethylene oxide-modified carbon nanotubes (PEO-CNTs) as the catalyst for 2e-ORR and using its loaded electrode as the cathode, the coupled electrolytic systems for H2O2 generation were set up in a diaphragm bath and in a diaphragm-free bath. It was found that the generated H2O2 in the electrolyte diffuses and causes oxidative decomposition on the anode, which is the main influent factor on the accumulated concentration in H2O2 in a diaphragm-free bath. [ABSTRACT FROM AUTHOR]

Photoanode‐driven photoelectrocatalytic (PEC) reduction of CO2 is an ideal way for solving problems such as the greenhouse effect and environmental crisis. In this study, a one‐step hydrothermal method is successfully used for the preparation of BiVO4 films doped with different mass fractions of Mo. In the results, it is shown that when Mo is doped at 1.5 wt%, photocurrent densities of up to 4.11 mA cm−2 are obtained, 3.36 times greater than those of undoped BiVO4, and there is a marked cathodic shifting of water oxidation reaction initiation potential. Subsequently, coupling it with the BiOBr nanosheet cathode, the generated CH3OH rate reaches 45.67 μmol L−1 h−1 cm−2 at a low applied voltage of 1.2 VRHE, with a Faraday efficiency of 60.68% for PEC CO2 reduction. This work is important for Bi‐based thin‐film self‐assembly coupled with PEC CO2 systems. [ABSTRACT FROM AUTHOR]

Aerobic photooxidation in the aqueous phase is a promising field, but it faces the challenge of water-induced photocatalyst deactivation. In this work, we prepared three TADF-based photocatalysts with enhanced hydrophobicity to protect the excited state against water. Efficient aerobic photooxidation of sulfides into sulfoxides was realized in water owing to their extended triplet state lifetimes. The recyclability and oxidation mechanism of the photocatalyst were also discussed. [ABSTRACT FROM AUTHOR]

Developing high connectivity (>8) three‐dimensional (3D) covalent organic frameworks (COFs) towards new topologies and functions remains a great challenge owing to the difficulty in getting high connectivity organic building blocks. This however represents the most important step towards promoting the diversity of COFs due to the still limited dynamic covalent bonds available for constructing COFs at this stage. Herein, highly connected phthalocyanine‐based (Pc‐based) 3D COFs MPc‐THHI‐COFs (M=H2, Ni) were afforded from the reaction between 2,3,9,10,16,17,23,24‐octacarboxyphthalocyanine M(TAPc) (M=H2, Ni) and 5,5′,5′′,5′′′,5′′′′,5′′′′′‐(triphenylene‐2,3,6,7,10,11‐hexayl)hexa(isophthalohydrazide) (THHI) with 12 connecting sites. Powder X‐ray diffraction analysis together with theoretical simulations and transmission electron microscopy reveals their crystalline nature with an unprecedented non‐interpenetrated shp topology. Experimental and theoretical investigations disclose the broadened visible light absorption range and narrow optical band gap of MPc‐THHI‐COFs. This in combination with their 3D nanochannels endows them with efficient photocatalysis performance for H2O2 generation from O2 and H2O via 2e− oxygen reduction reaction and 2e− water oxidation reaction under visible‐light irradiation (λ >400 nm). This work provides valuable result for the development of high connectivity functional COFs towards diverse application potentials. [ABSTRACT FROM AUTHOR]

Ballast water released from ships have been known to contaminate water bodies and soils and introduce invasive species into the immediate environment, if not properly treated or if not treated at all. There is therefore a need to design several strategies in preventing and/or ameliorating this and to establish the effectiveness of each strategy. This paper therefore investigates the effectiveness of the use of fenton oxidation in the remediation of ballast water contaminated soil. Soil samples were collected from Otorho Abraka and stimulated with ballast water in a laboratory scale experiment. The soil samples were mixed with solutions containing hydrogen peroxide and ferrous ions at varying concentrations. The reaction proceeded for twelve (12) weeks, then the samples were analyzed for removal of contaminants. There was pH reduction from 5.10 to 4.00, but increase in the total organic carbon from 2.80% to 3.40%. Total phosphorus was between 7.20 - 453mg/l, while total nitrogen ranged from 1.70mg/l to 2.10mg/l. There was also an increase in heavy metal content. Soil texture was slightly affected with Fenton reagent. The result showed a significant reduction in the concentration of pollutants with time, since more hydroxyl radicals reacted with the contaminants. Its efficiency and kinetics was established as firstorder reaction. [ABSTRACT FROM AUTHOR]

The water oxidation half-reaction at anodes is always considered the rate-limiting step of overall water splitting (OWS), but the actual bias distribution between photoanodes and cathodes of photoelectrochemical (PEC) OWS cells has not been investigated systematically. In this work, we find that, for PEC cells consisting of photoanodes (nickel-modified n -Si [Ni/ n -Si] and α-Fe2O3) with low photovoltage (V ph < 1 V), a large portion of applied bias is exerted on the Pt cathode for satisfying the hydrogen evolution thermodynamics, showing a thermodynamics-controlled characteristic. In contrast, for photoanodes (TiO2 and BiVO4) with V ph > 1 V, the bias required for cathode activation can be significantly reduced, exhibiting a kinetics-controlled characteristic. Further investigations show that the bias distribution can be regulated by tuning the electrolyte pH and using alternative half-reaction couplings. Accordingly, a volcano plot is presented for the rational design of the overall reactions and unbiased PEC cells. Motivated by this, an unbiased PEC cell consisting of a simple Ni/ n -Si photoanode and Pt cathode is assembled, delivering a photocurrent density of 5.3 ± 0.2 mA cm−2. [ABSTRACT FROM AUTHOR]

With the growing popularity of "green chemistry," the selective oxidation of alcohols using water as a reaction medium and oxygen as an oxidant has increased significantly in the last few years. However, the solubility of organic substances and oxygen in water is relatively poor and generates such a large mass transfer resistance, which seriously reduces the efficiency of aqueous phase reaction. This work employed the construction of TEMPO nanoreactors based on thermoresponsive polymers to lower mass transfer resistance and promote the selective oxidation of alcohol. Compared with free TEMPO, it was discovered that the tethered organocatalyst's reactivity in water under air atmosphere was extraordinarily high within the nanostructure. Moreover, the nanoreactors can be easily recovered by increasing the temperature after the reaction, which can recycle up to five times while still being highly active. This work would offer some fresh perspectives on carrying out environmentally friendly reactions and demonstrate an inventive method for multiphase reaction intensification. [ABSTRACT FROM AUTHOR]

In this work, a coupling system consisting of bismuth vanadate (BiVO4) and cobalt-based polyoxometalates (Co-POMs) was developed to enhance the oxygen evolution reaction. Crystallization-driven self-assembly and the wet chemical synthesis method were deployed in synthesizing Co-POMs and monoclinic–tetragonal mixed–phase BiVO4, respectively. The introduction of Co-POMs into a BiVO4-containing mixture significantly enhanced the water oxidation reaction, with a more than twofold increment in the total amount of oxygen evolved. For instance, 461.2 µmol of oxygen was evolved from the system containing 20 mg of Co-POMs compared to 195 µmol of oxygen produced from a pristine BiVO4 system. This extraordinary improvement in the oxygen evolution reaction indicates the existence of a positive synergic effect between BiVO4 and Co-POMs, in which Co-POMs could act as effective cocatalysts to extract photogenerated charge carriers generated by BiVO4 and improve the charge transfer process. However, the amount of oxygen produced was slightly reduced to 440.7 µmol with an increase in AgNO3 loading from 30 mg to 60 mg. This unforeseen phenomenon could be elucidated by the shielding effect of silver particles, in which a higher AgNO3 loading led to a more prominent shielding effect. The presence of silver nanoparticles on post-reaction BiVO4 was confirmed by TEM and XPS analysis. This newly established process scheme provides an insight into the development of an efficient photocatalytic oxygen evolution system in realizing future commercial applications toward green energy production. [ABSTRACT FROM AUTHOR]

Water splitting is considered a renewable and eco−friendly technique for future clean energy requirements to realize green hydrogen production, which is, to a large extent, hindered by the oxygen evolution reaction (OER) process. In recent years, two−dimensional (2D) carbon−based electrocatalysts have drawn sustained attention owing to their good electrical conductivity, unique physicochemical properties, and excellent electrocatalytic performance. Particularly, it is easy for 2D carbon−based materials to form nanocomposites, which further provides an effective strategy for electrocatalytic applications. In this review, we discuss recent advances in synthetic methods, structure−property relationships, and a basic understanding of electrocatalytic mechanisms of 2D carbon−based electrocatalysts for water oxidation. In detail, precious, non−precious metal−doped, and non−metallic 2D carbon−based electrocatalysts, as well as 2D carbon−based confined electrocatalysts, are introduced to conduct OER. Finally, current challenges, opportunities, and perspectives for further research directions of 2D carbon−based nanomaterials are outlined. This review can provide significant comprehension of high−performance 2D carbon−based electrocatalysts for water-splitting applications. [ABSTRACT FROM AUTHOR]

[Display omitted] • NiFe-codoping tactic is used to regulate the amorphous/crystalline heterophases. • Electronic structure has been effectively regulated for the catalyst. • Adsorption ability of catalyst for oxygenated intermediates is optimized in OER. • The content of oxygen vacancies in catalyst has been improved to boost OER. Oxygen evolution reaction (OER) is a crucial half-reaction in water splitting, generating hydrogen for sustainable development, but it is often subject to sluggish kinetics. Abundant transition metal-based OER electrocatalysts have been utilized to expedite the process. However, traditional amorphous catalysts suffer from low conductivity, while the activity of crystalline catalysts is also unsatisfactory. Herein, an amorphous/crystalline heterostructured Co-based hydroxide/tungstate was meticulously constructed and further tailored using a NiFe codoping method (NiFeCoW). Following NiFe codoping, the electronic structure had been modulated, subsequently altering the adsorption toward intermediates. From the electrochemical measurements, the NiFeCoW catalyst demonstrated superior electrocatalytic activity for OER in alkaline media, with a minimal overpotential of 297 mV at 10 mA cm−2 and a cell voltage of 1.57 V for water splitting. This study provides valuable guidance for regulating the amorphous/crystalline heterophase in catalysts through bimetallic modulating engineering. [ABSTRACT FROM AUTHOR]

BiVO 4 photoanode shows severe recombination of photogenerated carriers, which limits its water oxidation performance for photoelectrochemical (PEC) water splitting. In this paper, the surface of BiVO 4 photoanode was modified through the coupling of phosphotungstic acid (H 3 O 40 PW 12 ·xH 2 O, denotes as PWO) with CoOOH to address such drawbacks. At 1.23 V RHE , the photocurrent density of BiVO 4 /PWO/CoOOH photoanode reaches 2.80 mA/cm2, which is 2.59-fold that of bare BiVO 4 photoanode. Moreover, the initial onset potential of BiVO 4 /PWO/CoOOH photoanode is also negatively decreased by 270 mV than that of bare BiVO 4 photoanode. Detailed structural and electrochemical characterizations demonstrate that the decoration of PWO serves as an intermediate layer to promote the transport of holes from BiVO 4 to CoOOH, while the deposition of CoOOH acts as a protective layer as well as cocatalyst to reduce the photocorrosion and improve the PEC activities of BiVO 4. The synergistic coupling of PWO and CoOOH not only makes efficient bulk and surface charge separation, but also takes full advantage of photo-generated holes on the surface, which accelerates water oxidation kinetics, ultimately achieving an improvement in PEC water oxidation. PWO and CoOOH, which widens the range of light absorption and effectively enhances the capacity of light absorption, can therefore induce BiVO 4 to produce more photogenerated charge. Meanwhile, CoOOH facilitates the kinetics of water oxidation. The synergistic effect of PWO and CoOOH improves the PEC performance of BiVO 4. [Display omitted] • BiVO 4 /PWO/CoOOH composite photoanode is reasonably designed and synthesized. • BiVO 4 /PWO/CoOOH photoanode shows excellent stability for PEC. • BiVO 4 /PWO/CoOOH electrode exhibited a high PCD of 2.8 mA/cm2 at 1.23 V RHE. • Synergistic effects of PWO and CoOOH deposition improved the performance. [ABSTRACT FROM AUTHOR]

Oxygen evolution reaction (OER) is a well-known gas-involved reaction in which oxygen bubbles are formed and adhered on anode surface to lead to a sharp decline of performance. Iridium oxide (IrO 2) is the catalyst for water oxidation and is often used as a benchmark material. However, the factors affecting the bubbles detachment of IrO 2 are still unclear. Herein, we found that: 1. Nafion®, one of the main components of PEM membrane and usually used as electrode binder, can significantly increase the hydrophobicity of the electrode surface and is unfavorable to bubble detachment. 2. IrO 2 itself has good hydrophilicity but is not enough for efficient bubble separation, and no obvious linear relationship between bubble detachment performance and the particle size. 3. For improving bubble separation, irregularly rough surfaces should be avoided to prevent cavities trapping effect and multiple unnecessary bubble adhesion sites, both of which play the roles in stabilizing bubbles. In contrast, the uniformity and regularity of electrode surface should be paid more attention, as evidenced by comparing the surface morphology between drop-casting and pyrolysis in IrO 2 and RuO 2. • Nafion® can significantly enhance the hydrophobicity of the electrode surface and can't conducive to bubbles detachment. • Smaller particles tendency to facilitate bubbles detachment. • Amorphous IrO 2 can cause poor bubbles separation performance probably due to the surface of abundance g-OH. • Surface uniformity can enhance bubbles separation which is beneficial to the efficiency of the OER. [ABSTRACT FROM AUTHOR]

The sluggish electro-kinetics of electron-driven water oxidation restricts the electrocatalyst-assisted electrical to life-valued product conversion applications. Herein, for the first time, self-assembled nanochain network, iron-doped cobalt oxide (Fe–CoO) embedded boron-doped carbon nanotubes (B-CNT), is synthesized via a facile self-assembly-hydrolysis strategy followed by Ostwald-ripening assisted crystal-growth approach. Due to its unique features, such as porous nanochain, low dimensional network, heteroatom distribution, and electronic modulated-rich active sites, it can synergistically accelerate the complicated multistep 4e− electron transfer kinetics, which guarantees Fe–CoO@B-CNT delivering extraordinary OER activity. Herein, a very low Tafel (54.6 mV/dev) and the overpotential of 260 mV to achieve a partial current density of 10 mAcm−2 in alkaline medium. Thus outperforms noble-metal and most cobalt/carbon-based electrocatalysts; furthermore, the hybrid delivers outstanding physicochemical stability over 48 h deprived of degradation. This work gives new insights into the rational designing and self-assembling fabrication of a hetero-atom doped hierarchical nanochain network with high conductivity and abundant active sites to significantly boost water oxidation activity. [Display omitted] • Facile amine hydrolysis method is followed to construct Fe–CoO@B-CNT nanoframework. • Scalable, low-cost and earth-abundant catalyst is succeeded for robust alkaline OER. • Doping, synergism, mesopores, and nanostructures facilitate barrier-free electrokinetics. • The nanoframework shows the lowest overpotential of 260 mV with low Tafel values 54.6 mV/dec. • Non-precious 3D porous nanoarchitecture overtakes benchmark RuO 2 electrocatalysts. [ABSTRACT FROM AUTHOR]

The electrocatalytic synthesis of C–N coupling compounds from CO2 and nitrogenous species not only offers an effective avenue to achieve carbon neutrality and reduce environmental pollution, but also establishes a route to synthesize valuable chemicals, such as urea, amide, and amine. This innovative approach expands the application range and product categories beyond simple carbonaceous species in electrocatalytic CO2 reduction, which is becoming a rapidly advancing field. This review summarizes the research progress in electrocatalytic urea synthesis, using N2, NO2−, and NO3− as nitrogenous species, and explores emerging trends in the electrosynthesis of amide and amine from CO2 and nitrogen species. Additionally, the future opportunities in this field are highlighted, including electrosynthesis of amino acids and other compounds containing C–N bonds, anodic C–N coupling reactions beyond water oxidation, and the catalytic mechanism of corresponding reactions. This critical review also captures the insights aimed at accelerating the development of electrochemical C–N coupling reactions, confirming the superiority of this electrochemical method over the traditional techniques. [ABSTRACT FROM AUTHOR]

Peroxymonosulfate (PMS, HSO5-) is an increasingly popular oxidant for groundwater remediation via in situ chemical oxidation (ISCO). However, it is desired to evaluate the effect of phosphate on the PMS oxidation of organics in detail due to the saline characteristics of groundwater. In this study, ofloxacin (OFX) as a typical antibiotic was chosen as a model pollutant. The results indicated that 64% of OFX was degraded by PMS in the presence of HPO42- (PMS/HPO42- system), and the efficiency increased from 64% to 80% when the HPO42- concentration was increased from 0.1 mol/L to 0.3 mol/L. The corresponding pseudo-first-order reaction constants were 0.0086 and 0.02 min-1, respectively. In comparison, PO43- and H2PO4- showed almost no reactivity. Electron spin response (ESR) analysis and quenching tests proved that SO4·- and 1O2 were the main oxidizing species for OFX degradation in PMS/HPO42- system. Hence, HPO42- was the most effective form in PMS activation and its performance was highly pH and ionic strength sensitive. Given the ambient pH and phosphate concentration in saline groundwater, a considerable amount of HPO42- can be produced, which then serves as a homogeneous PMS activator in ISCO process. This finding provides new insights into ISCO process using PMS. [ABSTRACT FROM AUTHOR]

BiVO4 is one of the most promising photoanode materials for photoelectrochemical (PEC) solar energy conversion, but it still suffers from poor photocurrent density due to insufficient light‐harvesting efficiency (LHE), weak photogenerated charge separation efficiency (ΦSep), and low water oxidation efficiency (ΦOX). Herein, we tackle these challenges of the BiVO4 photoanodes using systematic engineering, including catalysis engineering, bandgap engineering, and morphology engineering. In particular, we deposit a NiCoOx layer onto the BiVO4 photoanode as the oxygen evolution catalyst to enhance the ΦOX of Fe‐g‐C3N4/BiVO4 for PEC water oxidation, and incorporate Fe‐doped graphite‐phase C3N4 (Fe‐g‐C3N4) into the BiVO4 photoanode to optimize the bandgap and surface areas to subsequently expand the light absorption range of the photoanode from 530 to 690 nm, increase the LHE and ΦSep, and further improve the oxygen evolution reaction activity of the NiCoOx catalytic layer. Consequently, the maximum photocurrent density of the as‐prepared NiCoOx/Fe‐g‐C3N4/BiVO4 is remarkably boosted from 4.6 to 7.4 mA cm−2. This work suggests that the proposed systematic engineering strategy is exceptionally promising for improving LHE, ΦSep, and ΦOX of BiVO4‐based photoanodes, which will substantially benefit the design, preparation, and large‐scale application of next‐generation high‐performance photoanodes. [ABSTRACT FROM AUTHOR]

A series of nanocrystalline iron oxide samples (M1–M5) which differ from each other in average crystallite size (from 26 to 37 nm) was studied. The raw material was nanocrystalline iron with an average crystallite size equal to 21 nm promoted with hardly reducible oxides: Al2O3, CaO, K2O (in total, max. 10 wt%). Nanocrystalline iron was subjected to oxidation with water vapor to achieve different oxidation degrees (α = 0.16–1.00). Metallic iron remaining in the samples after the oxidizing step was removed by etching. Magnetic resonance spectra of all samples were obtained at room temperature. All resonance lines were asymmetric and intense. These spectra were fitted by Lorentzian and Gaussian functions. All spectral parameters depend on the preparation method of the nanoparticles. We suppose that the Lorentz fit gives us a spectrum from larger agglomerated sizes whereas the Gaussian fit comes from much smaller magnetic centers. For the nanocrystalline samples with the largest size of iron oxide nanocrystallites, the highest value of total integrated intensity was obtained, indicating that at smaller sizes, they are more mobile in reorientation processes resulting in more settings of anti-parallel magnetic moments. The magnetic anisotropy should also increase with the increase in size of nanocrystallites. [ABSTRACT FROM AUTHOR]