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Inspired by natural photosynthesis, bio-photoelectrochemical (BPEC) cells based on photo-enzyme coupled catalysis hold great promise for energy conversion and chemical valorization. Here, we report an integrated BPEC system comprising a glucose dehydrogenase (GDH) modified meso-tetrakis(4-carboxyphenyl)-porphyrin/titanium dioxide (TCPP/TiO2) dye-sensitized photoanode and a mesoporous carbon hollow spheres/carbon paper (MCHS/CP) cathode for light-driven glucose oxidation and hydrogen peroxide (H2O2) production, respectively. Such a proposed bifunctional BPEC cell delivers a maximum power output of 0.24 ± 0.03 mW cm−2 with an open circuit voltage of 0.76 ± 0.01 V and achieves efficient H2O2 accumulation (rate: 0.94 ± 0.02 mM cm−2 h−1). Overall, our proof-of-concept assembly leverages the ascendancy of biocatalysis, photoelectrocatalysis, and electrosynthesis to provide an optimized design for biotic/abiotic coupling and expand the functional versatility of green energy devices. [ABSTRACT FROM AUTHOR]

The exploration of solid-state lithium metal batteries (SLMBs) with high-performance hybrid polymer electrolytes is in demand for the development of novel energy-storage systems with enhanced safety and high theoretical energy densities. In this study, for the first time, we report the synthesis of P(dodecafluoroheptyl methacrylate-co-methyl methacrylate) (P(DFMA-co-MMA)) as a polymer matrix to provide adsorption sites for Li+. Moreover, succinonitrile was introduced to suppress polymer crystallization, and the long fluorocarbon chains connected in series provided long-range channels for Li+ transmission. The resultant long-chain-fluorocarbon-driven hybrid solid polymer electrolyte (LFSPE) membranes could afford an exceptional ion conductivity of 6.78 × 10−4 S cm−1 at 25 °C, with a wide electrochemical stable window (0–4.713 V vs. Li/Li+) and high lithium-ion transference number (0.47). The poly(diallyl dimethyl ammonium)-bis(trifluoromethanesulfonyl)imide (PDDA-TFSI) interlayer was exploited to inhibit the side reactions on the Li metal surface and promote homogeneous Li plating. Thus, steady Li plating/stripping in LFSPE could be achieved under an areal capacity of 0.2 mA h cm−2 for 2000 h. The LiFePO4 (LFP), LiCoO2 (LCO) and LiNi0.8Co0.1Mn0.1O2 (NCM811) cells using the modified SLMB design scheme exhibited excellent rate capacity (specific capacity of 138.8, 109.6 and 145.8 mA h g−1 at 1C, respectively) and long-term cycling stability (98.8% capacity retention after 500 cycles for LFP; 81.4% and 71.9% capacity retention after 300 cycles for LCO and NCM811, respectively). This work offers a novel and effective SLMB system with high safety based on a hybrid solid polymer electrolyte. [ABSTRACT FROM AUTHOR]

We report a new method to fabricate highly stretchable and highly conductive fluorescent ionogels via self-catalytic cross-linking of poly(ionic liquid (IL))-based copolymers containing epoxy groups in ILs without adding any conventional cross-linkers and chromophores. Here, the ILs serve as a solvent, electrolyte, and catalyst, while the product of the ring-opening reactions acts as cross-linking junctions. The results reveal that these systems are typical autocatalytic systems and that the IL anion type significantly influences the curing reaction kinetics. These ionogels exhibit excellent stretchability (>1200%), high ionic conductivity (>1 mS cm−1), and good temperature tolerance (−40 to 200 °C). Surprisingly, the special cross-linking structures make the ionogels show typical aggregation-induced emission behavior and possess tunable photoluminescence properties. Moreover, ionogel-based strain sensors exhibit fast response speed, excellent temperature tolerance and stability, and can monitor various human motions. Therefore, our study provides a facile method to utilize several distinct properties of ILs and PILs for designing multifunctional ionogels that serve as flexible conductive and fluorescent materials. [ABSTRACT FROM AUTHOR]

Self-powered biosensors (SPBs) based on enzymatic biofuel cells (EFCs) and microbial fuel cells (MFCs) have attracted considerable attention due to their obvious advantages such as simple configuration and ease of miniaturization, and potential applications including clinical diagnosis, environmental monitoring, industrial process control, etc. In this review, we will summarize the recent advances in SPBs, focusing on the use of EFC-SPBs as power sources in combination with microelectronic and electrochromic devices, and the applications of MFC-based SPBs as sensors for detecting toxicity, chemical oxygen demand (COD), biochemical oxygen demand (BOD) and assimilable organic carbon (AOC). The efforts in, for example, boosting the energy, reducing the cost, and improving the sensing performance in terms of sensitivity, accuracy and dynamic detection range are discussed. Finally, future prospects for the development of MFC-based SPBs are presented. [ABSTRACT FROM AUTHOR]

An amorphous Co–Mo–B film on a Ti mesh (Co–Mo–B/Ti) is fabricated via one-step electrodeposition exhibiting a dramatically enhanced hydrogen evolution reaction (HER) performance in alkaline media. To attain a current density of 20 mA cm−2, such Co–Mo–B/Ti demands only an overpotential of 110 mV, 190 mV lower than that of the counterpart Co–B/Ti, with strong electrochemical durability to maintain its catalytic activity for at least 32 h. [ABSTRACT FROM AUTHOR]

Energy-efficient electrochemical water splitting is one important way to produce hydrogen fuel but still faces many challenges. In this communication, we report that an amorphous Ni–P alloy shell electrodeposited on a CuO nanowire array supported on copper foam (CuO@Ni–P NA/CF) can be used for efficient water splitting in alkaline media. As a 3D catalytic electrode, it exhibits excellent activity both for the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER) with overpotentials of 106 mV for HER and 275 mV for OER to achieve a current density of 30 mA cm−2 in 1.0 M KOH. This bifunctional electrode enables a high-performance alkaline water electrolyzer to achieve a current density of 30 mA cm−2 at a cell voltage of 1.71 V. [ABSTRACT FROM AUTHOR]

Co phosphides, although highly active for the hydrogen evolution electrocatalysis in acids, still deliver inferior performance in alkalis, limiting their application in alkaline water electrolysis. Building an effective Co phosphide/(hydroxide)oxide interface could be a viable way to improve the hydrogen evolution activity of Co phosphide catalysts under alkaline conditions, which however remains unexplored and challenging. In this communication, we report the facile development of a CoP–CeO2 hybrid nanosheet film on Ti mesh (CoP–CeO2/Ti) from easily made Co3O4–CeO2via a selective phosphidation strategy. In 1.0 M KOH, such CoP–CeO2/Ti achieves a geometrical catalytic current density of 10 mA cm−2 at a pretty low overpotential of 43 mV, 27 mV less than that for CoP/Ti. Remarkably, our CoP–CeO2/Ti also shows superior durability over CoP/Ti, suggesting that CeO2 greatly stabilizes the CoP catalyst. Density functional theory calculations demonstrate that CoP–CeO2 possesses a lower water dissociation free energy and a more optimal hydrogen adsorption free energy than CoP. This selective phosphidation strategy is universal in engineering the transition metal phosphide/oxide interface for applications. [ABSTRACT FROM AUTHOR]

Exploitation of efficient and earth-abundant electrocatalysts for the oxygen evolution reaction (OER) is of great importance. Herein, we report that the formation of an amorphous Mn–Co–P shell on MnCo2O4 can boost its OER activity in alkaline media. The core–shell Mn–Co–P@MnCo2O4 nanowire array on Ti mesh (Mn–Co–P@MnCo2O4/Ti) shows excellent electrochemical catalytic activity and requires an overpotential of 269 mV to drive 10 mA cm−2 in 1.0 M KOH, which is 93 mV less than that for the MnCo2O4 nanoarray. Notably, this catalyst also shows strong long-term electrochemical durability with its activity being maintained for at least 100 h and achieves a high turnover frequency of 1.06 s−1 at an overpotential of 450 mV. [ABSTRACT FROM AUTHOR]

It is highly attractive to develop efficient hydrogen-evolving electrocatalysts under neutral conditions. In this communication, we report an amorphous FeMoS4 nanorod array on carbon cloth (FeMoS4 NRA/CC) prepared by hydrothermal treatment of an FeOOH nanorod array on carbon cloth (FeOOH NRA/CC) in (NH4)2MoS4 solution. As a 3D electrode for hydrogen evolution electrocatalysis, this FeMoS4 NRA/CC demonstrates superior catalytic activity and strong long-term electrochemical durability in 1.0 M phosphate buffered saline (pH: 7). It needs an overpotential of 204 mV to drive a geometrical current density of 10 mA cm−2, which is 450 mV less than that for FeOOH NRA/CC. Density functional theory calculations suggest that FeMoS4 has a more favourable hydrogen adsorption free energy than FeOOH. [ABSTRACT FROM AUTHOR]

Developing earth-abundant electrocatalysts for efficient full water splitting under benign conditions is highly desired but still a significant challenge. In this communication, we report the development of a Mn–Co-based nanowire array as a complementary catalyst for efficient water splitting in near-neutral media. The Mn–Co–borate nanowire array on carbon cloth (Mn–Co–Bi/CC) was prepared via oxidative polarization of a MnCo2O4 nanowire array (MnCo2O4) in potassium borate (K-Bi), behaving as an efficient electrocatalyst for water oxidation with an overpotential of 366 mV to drive a catalytic current density of 10 mA cm−2 in 0.5 M K-Bi (pH: 9.2). MnCo2O4/CC exhibits outstanding hydrogen evolution activity requiring an overpotential of 293 mV at 10 mA cm−2 in 0.5 M K-Bi. The two-electrode electrolyser using Mn–Co–Bi/CC as the anode and MnCo2O4/CC as the cathode drives 10 mA cm−2 at a cell voltage of 1.97 V with strong long-term electrochemical durability and 100% faradaic efficiency. [ABSTRACT FROM AUTHOR]

The sluggish kinetics of the oxygen evolution reaction has severely hindered the energetic convenience of electrolytic water splitting. Herein, we demonstrate that a CoS2 nanoarray on Ti mesh (CoS2/TiM) behaves as an efficient and durable catalyst for the hydrazine oxidation reaction in 1.0 M KOH with 100 mM hydrazine, which requires the potential of 125 mV to achieve 100 mA cm−2. The high hydrogen-evolving activity of CoS2/TiM makes it a bifunctional catalyst for energy-saving electrolytic hydrogen generation by replacing water oxidation with hydrazine oxidation. To drive 100 mA cm−2, its two-electrode electrolyzer demands a low cell voltage of only 0.81 V and it exhibits remarkable long-term electrochemical durability and nearly 100% Faradic efficiency for hydrogen evolution. [ABSTRACT FROM AUTHOR]

Electrochemical water splitting has been considered as a promising strategy for hydrogen production, but the sluggish anodic oxygen evolution reaction (OER) limits the efficiency of overall water splitting. In this communication, we report a facile strategy to realize energy-saving hydrogen generation by replacing OER with a thermodynamically more favorable aloe extract (AE) oxidation reaction (AOR). An Fe-doped CoP nanosheet array (Fe-CoP/CC) is used as a bifunctional catalyst for both AOR and hydrogen evolution reaction (HER). The Fe-CoP/CCFe-CoP/CC couple requires a cell voltage of 1.51 V to drive 20 mA cm−2 in 1.0 M KOH containing AE; however, a cell volatge of 1.63 V is required to drive the same current density in the absence of AE. Fe-CoP/CC also exhibits strong long-term electrochemical durability and nearly 100% faradaic efficiency. [ABSTRACT FROM AUTHOR]

It is of great importance but still remains a key challenge to develop non-noble-metal bifunctional catalysts for efficient full water splitting under mild pH conditions. In this communication, we report the in situ electrochemical development of an ultrathin Ni–Bi layer on a metallic Ni3N nanosheet array supported on a Ti mesh (Ni3N@Ni–Bi NS/Ti) as a durable 3D core/shell structured nanoarray electrocatalyst for water oxidation at near-neutral pH. The Ni3N@Ni–Bi NS/Ti demands overpotentials of 405 and 382 mV to deliver a geometrical catalytic current density of 10 mA cm−2 in 0.1 and 0.5 M K–Bi (pH: 9.2), respectively, superior in activity to Ni3N NS/Ti and most reported non-precious metal catalysts under benign conditions. It also performs efficiently for the hydrogen evolution reaction requiring an overpotential of 265 mV for 10 mA cm−2 and its two-electrode electrolyser affords 10 mA cm−2 at a cell voltage of 1.95 V in 0.5 M K–Bi at 25 °C. [ABSTRACT FROM AUTHOR]

Exploitation of efficient water oxidation electrocatalysts under benign conditions is of great importance but remains a huge challenge. In this communication, we report the preparation of a cobalt-borate nanosheet array on a Ti mesh (Co-Bi/Ti) successfully converted from an electrodeposited α-Co(OH)2 nanosheet array in potassium borate (K-Bi) via in situ electrochemical tuning. The Co-Bi/Ti shows high electrocatalytic activity toward water oxidation with an overpotential of 469 mV to achieve a current density of 10 mA cm−2 in 0.1 M K-Bi, with long-term electrochemical stability with a turnover frequency of 0.15 s−1 at an overpotential of 600 mV. [ABSTRACT FROM AUTHOR]

The exploration of high-performance and cost-effective water oxidation catalysts operating under mild conditions is still urgent and challenging. In this communication, a nickel-borate nanoarray supported on carbon cloth (Ni-Bi/CC) has been fabricated through oxidative polarization of a nickel oxide nanoarray on CC (NiO/CC) in a borate electrolyte (pH 9.2). As a 3D electrode, this Ni-Bi/CC exhibits superior catalytic activity for water oxidation in 0.1 M potassium borate (K-Bi) solution, yielding a geometrical catalytic current density of 10 mA cm−2 at an overpotential of 470 mV. Notably, this electrode also demonstrates outstanding long-term electrochemical durability for 25 h with 100% Faradaic efficiency. [ABSTRACT FROM AUTHOR]

Electrode design is of significant importance in the construction of enhanced electrochemical sensing platforms, and nanoarrays are an attractive architecture in molecule detection with large specific surface area and easy access for target molecules. In this communication, we report on the development of a ternary NiCoP nanosheet array on a Ti mesh (NiCoP/Ti) as a non-noble metal efficient catalyst electrode for electro-oxidation of glucose in alkaline electrolytes. As an electrochemical sensor for glucose detection, NiCoP/Ti shows a fast response time of less than 3 s, a low detection limit of 0.13 μM (S/N = 3), and a high sensitivity of 14 586 μA mM−1 cm−2. This sensor is also stable with high selectivity, specificity and reproducibility, and its application for real sample analysis is also demonstrated successfully. [ABSTRACT FROM AUTHOR]

Large quantities of solutions containing oxalic acid and nitric acid are produced from nuclear fuel reprocessing, but oxalic acid must be removed before nitric acid and plutonium ions can be recovered in these solutions. The degradation of oxalic acid with Pt/SiO 2 as a catalyst in nitric acid solutions has the characteristics of a fast and stable reaction, recyclable catalyst, and no introduction of impurity ions into the system. This method is one of the preferred alternatives to the currently used reaction of KMnO 4 with oxalic acid but lacks theoretical support. Therefore, this study attempts to clarify the reaction mechanism of the method. First, there was no induction period for this catalytic reaction, and no evidence was found that the nitrous acid produced in the solution could have an effect on oxalic acid degradation. Furthermore, oxidation intermediates (structures of Pt-O) were formed through this reaction between NO 3 - adsorbed on the active sites and Pt on the catalyst surface, but H + greatly promoted the reaction. Additionally, oxalic acid degradation through the oxidative dehydrogenation reaction occurred between oxalic acid molecules (HOOC-COOH) and Pt-O, with ·OOC-COOH, which is easily self-decomposable especially in acidic solution, generated simultaneously, and finally CO 2 was produced., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Exploitation of efficient and earth-abundant electrocatalysts for the oxygen evolution reaction (OER) is of great importance. Herein, we report that the formation of an amorphous Mn-Co-P shell on MnCo 2 O 4 can boost its OER activity in alkaline media. The core-shell Mn-Co-P@MnCo 2 O 4 nanowire array on Ti mesh (Mn-Co-P@MnCo 2 O 4 /Ti) shows excellent electrochemical catalytic activity and requires an overpotential of 269 mV to drive 10 mA cm -2 in 1.0 M KOH, which is 93 mV less than that for the MnCo 2 O 4 nanoarray. Notably, this catalyst also shows strong long-term electrochemical durability with its activity being maintained for at least 100 h and achieves a high turnover frequency of 1.06 s -1 at an overpotential of 450 mV.

It is highly attractive to develop efficient hydrogen-evolving electrocatalysts under neutral conditions. In this communication, we report an amorphous FeMoS 4 nanorod array on carbon cloth (FeMoS 4 NRA/CC) prepared by hydrothermal treatment of an FeOOH nanorod array on carbon cloth (FeOOH NRA/CC) in (NH 4 ) 2 MoS 4 solution. As a 3D electrode for hydrogen evolution electrocatalysis, this FeMoS 4 NRA/CC demonstrates superior catalytic activity and strong long-term electrochemical durability in 1.0 M phosphate buffered saline (pH: 7). It needs an overpotential of 204 mV to drive a geometrical current density of 10 mA cm -2 , which is 450 mV less than that for FeOOH NRA/CC. Density functional theory calculations suggest that FeMoS 4 has a more favourable hydrogen adsorption free energy than FeOOH.

Bimetallic Pt-Pd nanoicosahedrons (NIs) with multiple {111} twins were obtained through a facile one-pot hydrothermal synthesis in a high shape selectivity of 82%. The {111}-enclosed NIs exhibited superior electrocatalytic activities to {111}-enclosed Pt-Pd nanotetrahedrons as well as commercial Pt catalysts (Pt black and Pt/C) for methanol oxidation., (This journal is © The Royal Society of Chemistry 2012)

An effective synthetic strategy is demonstrated for preparing highly ordered crystallized mesoporous TiO(2) by introducing rare earth in the synthesis process; the obtained product exhibits near-infrared photocatalytic activity.