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Developing new forms of flexible zinc–air (Zn–air) batteries is crucial to economic growth. Nevertheless, the absence of an oxygen evolution reaction catalyst with high catalytic efficiency and low-cost causes instability of Zn–air battery cycling and economic unviability, respectively. In this paper, a leaf-like N-doped carbon structure with CoS2 nanoparticles self-supported on carbon fiber paper (CoS2-CZ@CFP) was developed as an air electrode for Zn–air batteries, which not only uses nonprecious metal elements, but also has a self-supporting configuration, enhancing the contact between the catalyst and electrode while facilitating the transfer of electrons. Sulfur as the source gas was introduced into Co-doped metal–organic skeletons (Co-ZIFs) anchored on carbon fiber paper (CFP) for in situ vulcanizing transition metal Co, which successfully ensures the uniform distribution of sulfide particles in the carbon matrix, hence enriching active catalyst sites. The CoS2-CZ@CFP demonstrated an overpotential of 1.611 V at J = 50 mA cm−2, superior to RuO2@CFP (1.814 V). A Zn–air battery fabricated using the synthesized CoS2-CZ@CFP exhibited an extended life cycle of 117 h. This research paves the way for a novel method of designing self-supporting configurations of sulfides and carbon matrix composites as promising air electrodes applicable to Zn–air batteries. [ABSTRACT FROM AUTHOR]

It is significant to develop low-cost and highly efficient electrocatalysts for the hydrogen evolution reaction (HER) via electrochemical water splitting. Herein, we constructed P-doped NiCo2S4 nanowire arrays on carbon fiber paper (NiCo2S4−xPx/CFP) as a HER electrocatalyst in both acidic and alkaline media. Benefitting from P doping into NiCo2S4, the as-prepared NiCo2S4−xPx/CFP exhibits low HER overpotentials of 80 and 132 mV in acidic and alkaline media at a cathodic current density of 10 mA cm−2, respectively, which are far superior to counterparts of NiCo2S4 nanowire arrays on the carbon fiber paper (NiCo2S4/CFP). Meanwhile, the NiCo2S4−xPx/CFP presents excellent HER stability of 20 hours in acidic and alkaline media. From the results of density functional theory calculations, P doping can not only optimize the hydrogen adsorption energetics on each kind of atomic site of catalysts, but also strengthen the H2O molecule binding ability on the catalyst surface for the alkaline HER and favor kinetics of hydrogen adsorption and H2 formation on the catalyst surface for the acidic HER, eventually improving overall HER performances. The investigation of the HER mechanism modulated by P doping in our work offers novel inspiration to develop highly efficient ternary metal sulfides for the HER. [ABSTRACT FROM AUTHOR]

A well-designed support material between catalyst and substrate can always significantly enhance the performance of an electrode on water oxidation. In this work, a functional Ni and N-doped carbon layer (NNC) was designed on carbon paper (CP) via pyrolysis by using a controlled electrodeposited polyporphyrin as a precursor. Consequently, the fabricated NiFe-LDH/NNC/CP achieved a catalytic current density of 100 mA cm−2 at a small overpotential of 231 mV with a low Tafel slope of 26.0 mV dec−1, as well as high durability for more than 360 h. The insights are that N-doping reinforces the hydrophilicity and the catalyst binding capacity, while Ni-doping intensifies the conductivity. [ABSTRACT FROM AUTHOR]

Nowadays, the goal of carbon peaking and carbon neutrality has become a global consensus, and electrochemical CO2 reduction to provide high-value power fuel is one of the major technical approaches attracting significant research interests and application prospects. However, the inevitable hydrogen evolution reaction in water-based electrolyte systems crowds out the reactive sites of active metals, causing a low CO2 conversion efficiency. In this work, Zn nanosheets were prepared via electrodeposition on the surface of carbon paper and then modified with polytetrafluoroethylene (PTFE) to tune the wetting angle of the electrolyte. A CO faradaic efficiency of 90.2% was achieved for Zn NS-8% PTFE (contact angle: 136.8°) at the electrolytic voltage of −1.0 V vs. RHE along with an overall current density of −7.9 mA cm−2. Experimental results and molecular dynamics simulation revealed that PTFE weakened the aggregation of H2O molecules and was more beneficial for capturing and adsorbing CO2 molecules near the electrode surface. The active sites of hydrogen production were transformed into the reaction center for electrocatalytic CO2 reduction due to the hydrophobicity of the electrode, and the accumulation of the local CO2 concentration accelerated the kinetic activity for electrochemical conversion (CO2 to CO). This strategy of tuning the local environment offers an alternative approach for effective electrode manufacturing in liquid electrolytes. [ABSTRACT FROM AUTHOR]

The urea oxidation reaction (UOR), which possesses a low theoretical potential and superior kinetics, is an attractive substitute for the anodic oxygen evolution reaction (OER) in overall water splitting; however, the implementation of hydrogen production in overall urea splitting is impeded by the deficiency of highly efficient, durable and cost-effective catalysts. Herein, we fabricated an Ni2P–MoP2 heterostructure with a hierarchical structure grown on carbon paper (Ni–Mo–P/CP), which exhibited robust activity and outstanding durability for the electrocatalytic oxidation of urea. The Ni–Mo–P/CP catalyst possessed an ultralow potential of 1.39 V to obtain the current density of 100 mA cm−2, small Tafel slope (27 mV dec−1) and long-term durability with almost no decay within 15 h. The experimental characterization revealed that the optimized electronic structure and the synergistic effect of abundant exposed active sites in the Ni–Mo–P/CP catalyst contribute to the efficient UOR catalytic activity. This work enriches the candidate catalysts for the UOR and promotes the industrial development of hydrogen production. [ABSTRACT FROM AUTHOR]

Developing high-efficiency electrocatalysts for the hydrogen evolution reaction (HER) is of great importance. In this paper, dendrite-free Ni–Cu catalysts were synthesised via one-step pulse electrodeposition under a weak magnetic field (0.5 T). Regardless of the direction of the magnetic field, the ions were affected by the magnetohydrodynamic (MHD) effect, which greatly promoted the mass transfer and dispersion uniformity, and suppressed the uncontrollable agglomeration by electrodeposition. It was found that the nucleation mechanism changed from progressive nucleation under a 0 T magnetic field to instantaneous nucleation under a 0.5 T magnetic field. Large-scale (325 nm, 0 T) dendrite growth on the single-sided plane was successfully suppressed, and replaced by smaller (90 nm, 0.5 T) and uniformly distributed cluster growth around the carbon paper. In addition, the (111) plane was strengthened by the magnetic field. Electrochemical analysis showed that the Ni–Cu catalysts exposed more surface area and exhibited greatly enhanced catalytic activity, which only needed −57.3 mV to deliver the current density of 10 mA cm−2 with a small Tafel slope of 99.4 mV dec−1 in 1 M KOH. Overall, magneto-electrodeposition, especially under weak magnetic field conditions, provides great promise for the preparation of HER catalysts. [ABSTRACT FROM AUTHOR]

Benefiting from a high overpotential of the competitive hydrogen evolution reaction with a carbon paper cathode, the desired electrochemical reduction of imines was achieved with high faradaic efficiency by using H2O as a H-source. With this sustainable atom-economic strategy, a series of potentially versatile amines were obtained in medium-to-high yields (49–86%). [ABSTRACT FROM AUTHOR]

Searching and developing earth-abundant electrocatalysts with predominant activity and favorable stability are significant to resolve increasing environmental pollution and serious energy crisis. In this paper, Mo-based nanowire arrays (NWAs) were synthesized on carbon fiber paper (CFP), and then Ru–MoP NWAs/CFP was successfully assembled through impregnation of Ru and phosphorization. The as-obtained Ru–MoP NWAs/CFP exhibited excellent performance over a broad pH range. As a result, overpotentials of 39.0, 49.9, and 67.1 mV were required to reach the current density of 10 mA cm−2 in 0.5 M H2SO4, 1 M KOH, and 1 M PBS, respectively. The outstanding performance of Ru–MoP NWAs/CFP is mainly related to the introduction of Ru and P atoms, which may enhance the conductivity of the catalyst and develop additional HER active sites. Our work may afford a novel designing approach to develop high performance HER electrocatalysts. [ABSTRACT FROM AUTHOR]

Here, polyaniline (PANI) is reported loaded on carbon paper to modify the carbon paper-PANI-Pt electrode surface, tailoring the electrocatalytic capability towards the hydrogen evolution reaction and ethanol oxidation reaction. The reasons for the enhancement by the PANI layer are attributed to the hydrophilic electrode surface, uniform dispersion of Pt, and large electrochemical active surface. [ABSTRACT FROM AUTHOR]

Bimetallic two-dimensional (2D) metal–organic framework (MOF) materials display excellent electrocatalytic performance due to the synergistic effect between metals and the advantage of the 2D structure. In this work, Cu was introduced into the 2D Co-MOF structure, and a 2D book-like CuCo-MOF structure was fixed on carbon fiber paper (CFP) for direct electrochemical glucose detection and oxygen evolution reaction (OER). The materials showed good electrocatalytic glucose detection performance with a sensitivity as high as 6.861 mA mM−1 cm−2 and a detection limit as low as 0.12 μM. For the OER, when the current density is 10 mA cm−2, the overpotential (η) is 340 mV, and good stability is maintained for about 10 h without current attenuation. This work not only exploits a new 2D MOF structure containing Cu, but also expands the potential of Cu-containing MOF materials in the electrocatalytic OER, making a contribution to the field of energy conversion and biomolecular sensing. [ABSTRACT FROM AUTHOR]

The New Journal of Chemistry is a publication that features articles and papers on various topics in chemistry. The current issue includes papers on lithium-sulfur batteries, graphene, and carbon nanotubes, among others. The journal is published by The Royal Society of Chemistry and the Centre National de la Recherche Scientifique. The papers provide valuable insights and findings in their respective fields of research, covering topics such as compound synthesis, crystal structures, magnetic behavior, and the development of new materials for applications like photocatalysis and electrocatalysis. The journal also offers professional recognition and development opportunities for scientists. [Extracted from the article]

The document is a contents list for the journal CrystEngComm, which focuses on the design and understanding of solid-state and crystalline materials. The issue includes various articles and papers on topics such as organic charge transfer complexes, metal organic frameworks, mechanical properties of cocrystals, and scintillation crystals. The journal is published by The Royal Society of Chemistry, a leading chemistry community that reinvests its profits back into the chemistry community. [Extracted from the article]

The New Journal of Chemistry, published by the Royal Society of Chemistry, features articles on a wide range of topics in chemistry. The current issue covers subjects such as nanosized metals, liquid catalyzed growth of graphene, and photocatalytic CO2 reduction. The journal aims to provide innovative and cutting-edge reports that have a strong chemical component and broad appeal. This document is a compilation of research papers from the journal, covering topics such as electrocatalysts, nanocomposites, halogenation reactions, supramolecular assembly, and more. The papers explore various applications, including agriculture and waste digestion. [Extracted from the article]

As one of the effective methods for hydrogen production, water electrolysis has been widely studied. However, the high overpotential challenge faced by the anode and the limitation of the electron transfer rate in this process significantly inhibit the efficiency of hydrogen production, which has become the main obstacle to overcome in the current research. The use of thermodynamically more favorable organic compounds to oxidize at the anode instead of traditional water oxidation (OER) is an effective strategy to optimize the process of electrolytic hydrogen production. In this paper, Ni3S2 catalysts co-doped with non-noble metals Li and Mn were prepared on nickel foam and used for the glycerol oxidation reaction (GOR) coupled with the hydrogen evolution reaction (HER). In alkaline solution, Li, Mn–Ni3S2@NF exhibits good GOR and HER performance. Specifically, overpotentials of 1.58 V vs. RHE and 0.54 V vs. RHE are required to reach a current density of 200 mA cm−2, respectively, and the catalytic performance of the material remains good after a long-term test. Li, Mn–Ni3S2@NF as a bifunctional catalytic material oxidizes glycerol to formate, and its faradaic efficiency (FE) is as high as 91%, and the volume of hydrogen production is close to the theoretical value. In addition, the replacement of the OER by the GOR can reduce the energy consumption by about 17.44%. [ABSTRACT FROM AUTHOR]

Efficient alkaline hydrogen evolution electrodes must be used for hydrogen production in anion exchange membrane water electrolyzers (AEMWEs). Therefore, we fabricated a NiMnS catalyst with a Mn-rich surface, which was self-supported on Ti paper through one-step electrodeposition. Mn doping endowed the catalyst with a unique hollow morphology and lattice-distorted structure. Consequently, the NiMnS/Ti electrode exhibited a large number of exposed electrochemical surfaces and effective active sites and a high hydrogen evolution reaction (HER) activity. Specifically, in half-cell measurements, the NiMnS/Ti electrode exhibited an overpotential of 65 mV at 10 mA cm−2, which was lower than that of NiS/Ti (102 mV) and indicated its superior HER activity. When the proposed cathode was applied in an AEMWE single cell, the device achieved a high current density of up to 0.9 A cm−2 at a cell potential of 2.0 V. [ABSTRACT FROM AUTHOR]

The use of a methanesulfonic acid (MSA) electrolytic system is recommended as a green method for hydrometallurgical recovery of metallic Pb from waste lead-acid batteries (LABs), contributing to the sustainable protection of the ecosystem. Nevertheless, the system's high energy consumption is a current issue due to the substantial overpotential of the oxygen evolution reaction (OER) and competitive anodic oxidation of Pb2+. Herein, we propose an IrFe/nitrogen-doped pyrolytic carbon black (IrFe/NCBp) composite as a novel OER catalyst for the MSA electrolytic system, which demonstrates advanced OER catalytic efficiency and selectivity for H2O oxidation. This can be ascribed to the catalyst's thoughtful design, which enhances the number and uniformity of Ir and Fe species via increasing the specific surface area and employing NCBp as a sustainable substrate. The optimized IrFe/NCBp composite exhibits superior OER performance, with a low 252 mV@10 mA cm−2 overpotential and a 62 mV dec−1 Tafel slope, and excellent durability in a 1 M MSA electrolyte for 30 h operation compared to commercial Ir/C. In contrast to carbon paper (CP) and commercial Ir/C anodes, the anodic reaction of IrFe/NCBp is primarily OER-driven (97%) in 1 M MSA and 0.2 M Pb2+ electrolyte for Pb recovery. This effectively circumvents the high potential oxidation of Pb2+ into PbO2, reducing the electrolytic voltage to 488 kWh for the recovery of 1 ton Pb metal. This work provides a green, low-carbon footprint solution for the MSA electrolytic system, thereby promoting the commercialization of the hydrometallurgical Pb recovery. [ABSTRACT FROM AUTHOR]

In this paper, a novel Pt/CoP/C photo-electro synergistic catalyst was successfully synthesized by a hydrothermal method combined with phosphorus doping treatment. The addition of Vulcan XC-72R is in favor of effectively preventing agglomeration of active catalytic sites, resulting in more uniform and smaller Pt and CoP nanoparticles. The as-obtained Pt/CoP/C shows excellent photo-electro catalytic performance for the HER with simulated solar light irradiation. The optimal hydrogen production is 5384.18 mmol h−1 g−1, which is obviously higher than that of the commercial catalyst (20 wt% Pt/C: 4608.52 mmol h−1 g−1). The research results show that introducing cobalt phosphide into the Pt catalyst can improve the electrocatalytic activity and stability for the HER; in particular, the existence of Co3O4 in Pt/CoP/C leads to an efficient photo-electro catalysis under irradiation, which significantly improves the catalytic activity of Pt. The results above provide a novel strategy for the rational design of cost-effective Pt-based composites towards a fast HER. [ABSTRACT FROM AUTHOR]

Platinum-based catalysts exhibit outstanding electrocatalytic performance in the hydrogen evolution reaction (HER). However, platinum-based catalysts face significant challenges due to their rarity and high cost. This paper endeavors to shed light on a promising alternative: polyoxometalate (POM)-based catalysts, which possess significant potential for the synthesis of non-noble metal-based catalysts for the HER. Utilizing POMs as raw materials to assemble POM-derived materials, including POM-derived crystalline materials, metal sulfides, phosphides, carbides, nitrides, and so on, has emerged as an effective approach for the synthesis of hydrogen evolution electrocatalysts. This approach offers advantages in both stability and electrocatalytic performance. This comprehensive review navigates through latest progress in the assembly strategy and HER performance of POM-based crystal materials, alongside discussion on transition metal compounds derived from POMs, such as carbides, phosphides, and sulfides. Besides, future developments in POM-derived electrocatalyst regulation of the electrochemical HER are prospected. [ABSTRACT FROM AUTHOR]

Hybrid water electrolysis (HWE) is a promising pathway for the simultaneous production of high-value chemicals and clean H2 fuel. Unlike conventional electrochemical water splitting, which relies on the oxygen evolution reaction (OER), HWE involves the anodic oxidation reaction (AOR). The AORs facilitate the conversion of organic or inorganic compounds at the anode into valuable chemicals, while the cathode carries out the hydrogen evolution reaction (HER) to produce H2. Recent literature has witnessed a surge in papers investigating various AORs with organic and inorganic substrates using a series of transition metal-based catalysts. Over the past two decades, metal–organic frameworks (MOFs) have garnered significant attention for their exceptional performance in electrochemical water splitting. These catalysts possess distinct attributes such as highly porous architectures, customizable morphologies, open facets, high electrochemical surface areas, improved electron transport, and accessible catalytic sites. While MOFs have demonstrated efficiency in electrochemical water splitting, their application in hybrid water electrolysis has only recently been explored. In recent years, a series of articles have been published; yet there is no comprehensive article summarizing MOFs for hybrid water electrolysis. This article aims to fill this gap by delving into the recent progress in MOFs specifically tailored for hybrid water electrolysis. In this article, we systematically discuss the structure–property–performance relationships of various MOFs utilized in hybrid water electrolysis, supported by pioneering examples. We explore how the structure, morphology, and electronic properties of MOFs impact their performance in hybrid water electrolysis, with particular emphasis on value-added chemical generation, H2 production, potential improvement, conversion efficiency, selectivity, faradaic efficiency, and their potential for industrial-scale applications. Furthermore, we address future advancements and challenges in this field, providing insights into the prospects and challenges associated with the continued development and deployment of MOFs for hybrid water electrolysis. [ABSTRACT FROM AUTHOR]

In this paper, we provide a novel electrode switch (ES) method to improve the stability of the alkaline electrolyzer toward water splitting. The voltage of the alkaline electrolyzer consisting of commercial Ni mesh electrodes utilizing the ES mode exhibits extreme stability because highly active Ni oxide(hydroxide) with oxygen defects is in situ formed during the hydrogen evolution reaction (HER) polarization process. [ABSTRACT FROM AUTHOR]

Designing a robust bifunctional water splitting catalyst at low cost is of great importance for water splitting. Herein, the in situ-generated MoS2/NiS2 nanosheet heterostructures by cobalt incorporation on carbon paper (Co–MoS2/NiS2/CP) are first obtained by applying a scalable chemical vapor vulcanization approach. Based on the synergistic effects of cobalt element doping and the construction of MoS2/NiS2 heterostructures, the much enhanced electrocatalytic performance for full water electrolysis is clearly revealed. In particular, the electronic structure of MoS2/NiS2 heterostructures was further effectively modified by cobalt incorporation along with the electron density of catalytic sites, which both promote the Volmer step to speed up alkaline hydrogen evolution reaction (HER) and optimize the oxygen-containing intermediate adsorption to enhance oxygen evolution reaction (OER). Consequently, Co–MoS2/NiS2/CP heterostructures presented low overpotentials (HER: η10 = 109 mV; OER: η10 = 323 mV) in the basic solution. Furthermore, Co–MoS2/NiS2/CP was designed as a two-electrode alkaline electrolytic configuration for full water electrolysis. This strategy experimentally illustrates the feasibility of designing a conventional electrocatalyst for water electrolysis via the cooperative effects of metal doping and heterostructured engineering. [ABSTRACT FROM AUTHOR]

Rational design and controllable synthesis of transition metal multi-anionic structures to cooperatively catalyze the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER) remain a great challenge due to the requirements of high current density and long-term durability for water splitting. Herein, a self-supported sheet-on-sheet hierarchical interface was synthesized via a facile corrosion engineering strategy, where the Ni3S2 microsheet arrays were pre-grown on nickel foam and they provided abundant surface active sites to grow FeOOH nanosheets vertically. The obtained FeOOH/Ni3S2 heterostructure exhibited well-defined dimensions and intimate interface contact with oxygen and a sulfur anion structure, which can modulate the electronic structure of interfacial active sites. Hence, the optimized FeOOH/Ni3S2 required overpotentials of 345 mV and 269 mV to achieve a current density of 100 mA cm−2 for the HER and the OER, respectively. Moreover, it required a voltage of 1.855 V to achieve overall water splitting at a current density of 100 mA cm−2. The interfacial electronic interaction and multi-anionic hierarchical structure not only facilitate the electron transfer between the FeOOH/Ni3S2 surface and intermediate species but also accelerate the kinetic rate. This paper provides a new avenue to design multi-anionic hierarchical structures as cost-effective and highly stable electrocatalysts for practical overall water splitting. [ABSTRACT FROM AUTHOR]

The shortage of freshwater resources in the world today has limited the development of water splitting, and our eyes have turned to the abundant seawater. The development of relatively low-toxicity and high-efficiency catalysts is the most important area in seawater electrolysis. In this paper, the preparation of NiS2@Co4S3@FeS via a hydrothermal method on nickel foam has been studied for the first time. In the process of vulcanization, Fe will first generate FeS by virtue of its high affinity for vulcanization. Once Fe is vulcanized, the residual sulfur will be used to generate NiS2, while the vulcanization of Co requires a higher sulfur concentration and reaction temperature; thus, Co4S3 will be generated last. NiS2@Co4S3@FeS is confirmed to have excellent hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) catalytic properties in alkaline seawater. Its unique structure allows it to expose more reaction centres, and the synergies between the multiple metals optimize the charge distribution of the material and accelerate the OER and HER kinetics. NiS2@Co4S3@FeS requires overpotentials of only 122 mV and 68 mV for the OER and HER when reaching 10 mA cm−2, which is superior to most catalysts reported to date for seawater electrolysis, and the material displays acceptable stability. In an electrolytic cell composed of both positive and negative electrodes, when the current density is 10 mA cm−2, the NiS2@Co4S3@FeS material displays a low overpotential of only 357 mV for seawater splitting. Density functional theory shows that the FeS electrode has the optimum Gibbs free energy of H to accelerate reaction kinetics, and the synergistic catalysis of the NiS2, Co4S3 and FeS materials promotes the hydrogen production activity of the NiS2@Co4S3@FeS electrode. This work proposes a novel idea for designing environmentally friendly seawater splitting catalysts. [ABSTRACT FROM AUTHOR]

Urea electrolysis can be used to treat wastewater containing urea and alleviate the energy crisis, so it is one of the best ways to solve environmental and energy problems. This paper reports the synthesis of M doped NiVS (M = Co, Ce and Cr) composites by a simple hydrothermal process for the first time. What is noteworthy is that the Ce-NiVS material as a catalytic electrode requires only 141 mV overpotential for the hydrogen evolution reaction (HER) and 1.291 V potential for the urea oxidation reaction (UOR) at a current density of 10 mA cm−2 in 1.0 M KOH and 0.5 M urea mixed alkaline solution. Using Ce-NiVS/NF as both the anode and cathode for urea electrolysis, a current density of 10 mA cm−2 is driven by a voltage of only 1.55 V, which is better than most previous catalysts. Experimental results demonstrate that the excellent catalytic activity of Ce-NiVS materials is due to the formation of a large number of active sites and the improvement of conductivity due to doping with Ce. Density functional theory calculation shows that the VS4 material has a small Gibbs free energy of hydrogen adsorption, which plays a major role in the hydrogen production process, and Ce-NiS has a higher density of states (DOS) near the Fermi level, indicating that Ce-NiS has better electronic conductivity. The synergistic catalysis of VS4 and Ce-NiS promoted the hydrogen production performance of the Ce-NiVS material. This work provides guidance for the optimization and design of low-cost electrocatalysts to replace expensive precious metal-based electrocatalysts for overall urea electrolysis. [ABSTRACT FROM AUTHOR]

The development of a bifunctional ruthenium-based electrocatalyst that can efficiently and economically drive both the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) remains challenging because ruthenium species can undergo severe agglomeration during preparation which can significantly reduce the catalytic activity. Constructing supported metal catalysts can not only improve the stability of Ru but also improve the catalytic performance by adjusting the electronic structure, which is an effective way to solve the current challenges. In this paper, Ru-loaded MoO2/MoO3 heterostructures (Ru–MoOx) with oxygen vacancies were successfully synthesized by controlling the annealing temperature. This special structure can effectively tune the electronic structure, enhance the electrical conductivity and increase the active sites, thus improving the catalytic activity of the catalyst. Performance studies have shown that Ru–MoOx exhibits excellent HER and OER performance in alkaline media. And it is not surprising that the overall water decomposition performance of Ru–MoOx is also excellent, requiring only a cell voltage of 1.54 V to reach 10 mA cm−2. [ABSTRACT FROM AUTHOR]

The development of high-performance and cost-effective electrocatalysts for the oxygen evolution reaction (OER) is critical to renewable energy conversion and storage technologies. Among of them, metal organic frameworks (MOFs) have been proved to be effective substitutes for precious metals. In this paper, a series of mixed NiCoFe-MOFs with low crystallinity were synthesized by a simple one-step solvothermal method, which can be used as a direct electrocatalyst for the OER. Notably, the flower-like nanocatalyst NiCoFe-MOF-2 exhibits a hierarchical pore network and a large specific surface area (149.6 m2 g−1), which results in an adjustable electronic structure, effective mass transfer, and abundant exposed active sites. In addition, due to the synergy between the three metals Fe, Co and Ni, NiCoFe-MOF-2 can exhibit excellent electrocatalytic OER performance, with a low overpotential of 321 mV at 10 mA cm−2, superior to commercial RuO2 (379 mV), a Tafel slope of 48 mV dec−1 and long-term stability. The result may stimulate more designs of MOF-derived catalysts with multi-scale structures and multi-components designed for various electrochemical energy conversion devices. [ABSTRACT FROM AUTHOR]

The development of noble-metal-free electrocatalysts with high catalytic efficiency, low cost, and high durability in pH-universal media is encountering a bottleneck in practical applications. In this paper, Ni@MoN-700 coral hybrids were prepared using hydrogen evolution reaction (HER) catalysts, which were synthesized by a high-temperature reduction of NiMoO4 nanorods with urea. It was found that the annealing temperature seriously affects the surface morphology and chemical composition of the catalysts. Besides, structural reorganization occurred during the HER, which involved the joining of pyrrolic N, metal nitrogen, Mo3+, and Mo6+, governing the HER performance. Also, during the HER, Ni and Mo could synergistically improve the overall catalytic activity of the catalysts, via electronic interactions. These advantages endow Ni@MoN-700 with exceptional endurance and great HER activity, with a low overpotential of 30 mV and 76 mV at 10 mA cm−2 in alkaline and acidic media. These characteristics are similar to those of Pt under alkaline conditions. NiMoN catalysts show unusual activity and long-term stability, indicating a wide range of potential applications. [ABSTRACT FROM AUTHOR]

Efficient electrocatalysts are in great demand for renewable energy storage systems. Herein, we propose an ultrafast heating strategy to fabricate an efficient Ir/CP-UH catalyst for the oxygen evolution reaction (OER). Experimental results demonstrated that the ultrasmall Ir nanoparticles (≈1–3 nm) and clusters (<1 nm) were highly dispersed on the carbon paper support after a short thermal shock (∼5 s). The catalyst showed a low overpotential of 260 mV at 10 mA cm−2 and remarkable mass activity of about 13.8 times higher than that of the current state-of-the-art commercial Ir/C catalyst. This ultrafast heating strategy can also be applied to other catalyst systems for OER and other electrochemical reactions. [ABSTRACT FROM AUTHOR]

Electrocatalytic water splitting is considered to be one of the most promising technologies for large-scale sustained production of H2. Developing non-noble metal-based electrocatalytic materials with low cost, high activity and long life is the key to electrolysis of water. Transition metal sulfides (TMSs) with good electrical conductivity and a tunable electronic structure are potential candidates that are expected to replace noble metal electrocatalysts. In addition, self-supported electrodes have fast electron transfer and mass transport, resulting in enhanced kinetics and stability. In this paper, TMS self-supported electrocatalysts are taken as examples and their recent progress as hydrogen evolution reaction (HER) electrocatalysts is reviewed. The HER mechanism is first introduced. Then, based on optimizing the active sites, electrical conductivity, electronic structure and adsorption/dissociation energies of water and intermediates of the electrocatalysts, the article focuses on summarizing five modulation strategies to improve the activity and stability of TMS self-supported electrode electrocatalysts in recent years. Finally, the challenges and opportunities for the future development of TMS self-supported electrodes in the field of electrocatalytic water splitting are presented. [ABSTRACT FROM AUTHOR]

Electrochemical water splitting offers the potential for environmentally friendly hydrogen and oxygen gas generation. Here, we present the synthesis, characterization, and electrochemical analyses of four organic polymers where metalloporphyrins are the active center nodes. These materials were obtained from the polymerization reaction of poly(p-phenylene terephtalamide) (PPTA) with the respective amino-functionalized metalloporphyrins, where M = Fe, 1; Co, 2; Ni, 3; Cu, 4. Scanning and transmission electron microscopy images (SEM and TEM) show that these polymers exhibit a layer-type morphology, which is attributed to hydrogen bonding and π–π stacking between the metalloporphyrin nodes. The synthesized materials were characterized by X-ray photoelectron spectroscopy (XPS), X-ray powder diffraction (XRD), energy-dispersive X-ray spectroscopy (EDX), UV-Vis spectroscopy, and Fourier-transform infrared spectroscopy (FT-IR). Among the materials studied, the cobalt-based polymer, 2, demonstrates a bifunctional electrocatalytic activity for oxygen (OER) and hydrogen (HER) evolution reactions with overpotentials (η10) of 337 mV and 435 mV, respectively. The Fe, 1, and Ni, 2, polymers are less active for HER with maximum current densities (jmax) of 12.6 and 19.1 mA cm−2 and η10 678 mV, 644 mV. Polymer 2 achieves a jmax of 37.7 mA cm−2 for HER and 133 mA cm−2 for OER. The copper-based material, 4, on the other hand, shows selectivity towards HER with an overpotential (η) of 436 mV and a maximum current density (j) of 45.5 mA cm−2. The bifunctional electrocatalytic performance was tested in the overall water-splitting setup, where polymer 2 requires a cell voltage of 1.64 V at 10 mA cm−2. This work presents a novel approach to heterogenized molecular systems, providing materials with exceptional structural characteristics and enhanced electrocatalytic capabilities. [ABSTRACT FROM AUTHOR]

Herein, an A3-type and an A2B-type meso-thiophene-substituted CoIIIcorrole are prepared and their electronic structures are investigated. Interestingly, these two CoIIIcorroles are facilely polymerized under electrochemical conditions and rationally controlled by polymerizing cycles, speed, molecular structure as well as co-polymerizations. In addition, these conductive CoIIIcorrole–polymers exhibit a significant increase and tunable electrochemically catalyzed hydrogen evolution behaviours with the best overpotential E = 0.091 V (j = 10 mA cm−2) in aqueous media. [ABSTRACT FROM AUTHOR]

In recent years, as a green renewable energy production technology, electrochemical water splitting has demonstrated high development potential. Many materials have been reported as successful catalysts in the water-splitting field. However, it is still a huge challenge to produce bifunctional electrocatalysts for the efficient and sustainable generation of hydrogen and oxygen simultaneously. Herein, we successfully developed oxygen vacancies abundant CuCo layered double oxide (Ov-CuCo-LDO) hollow nanotube arrays (HNTAs) loaded on nickel foam as advanced electrocatalysts for total water splitting. When the current density was 10 mA cm−2, the Ov-CuCo-LDO HNTAs exhibited outstanding onset overpotentials of 53.9 and 72.5 mV for the hydrogen evolution and oxygen evolution reactions (HER and OER) in alkaline medium, respectively, because of the bimetallic synergistic effect between the cobalt and copper and the unique hollow porous structure. In addition, an as-assembled Ov-CuCo-LDO‖‖Ov-CuCo-LDO electrolytic cell showed a small potential of 1.55 V to deliver a current density of 10 mA cm−2. Moreover, it also showed remarkable durability after long-term overall water splitting for more than 20 h. The research results in this paper are of great interest to practical applications of the water decomposition process, providing clear and in-depth insights into preliminary robust and efficient multifunctional electrocatalysts for overall water splitting. [ABSTRACT FROM AUTHOR]

In this paper, NiCo2S4 was coated on the surface of WS2 of a 1T/2H mixed phase by a two-step hydrothermal method to form an in situ core–shell structure. The unique S-scheme heterojunction of the NiCo2S4@WS2 core–shell composite photocatalyst improved the easy recombination of carriers caused by the narrow band gap of NiCo2S4 and WS2, and improved the photocatalytic hydrogen production performance. The loading ratio of NiCo2S4@WS2, the addition of Eosin Y, and the pH value of TEOA were optimized. Under the optimal conditions, the hydrogen production rate reached 5.814 mmol g−1 h−1, which is about 8.55 times and 3.35 times the hydrogen evolution rates of NiCo2S4 and WS2, respectively. The composite catalyst exhibits excellent charge separation efficiency in photoelectrochemistry, PL and BET tests, carrier transport rate and large specific surface area that can provide more active sites, which are the main factors for the improvement of the hydrogen evolution performance. This paper demonstrates new design strategies to drive efficient photocatalytic hydrogen production by building in situ core–shell structures and optimizing the carrier transport paths, which will yield new insights. [ABSTRACT FROM AUTHOR]

In this paper, the structural characteristics and catalytic mechanism for hydrogen evolution of ammonia borane of non-metal (N, S) doped CoP catalysts were studied in detail by density functional theory (DFT) calculations. Specifically, we first investigated the structure of the cobalt phosphide catalyzed ammonia borane models. In addition, based on the most stable structures, the mechanism of the hydrogen evolution reaction of ammonia borane catalyzed by three catalysts was studied, and four feasible reaction paths for the hydrogen evolution reaction of ammonia borane catalyzed by three catalysts were discussed. By comparing the activation energies of the control steps of different reaction paths, the optimal reaction paths for the hydrogen evolution of ammonia borane catalyzed by three different catalysts were determined. The catalytic activities of the three catalysts for the hydrogen evolution of ammonia borane were compared. We found that the N-doped catalyst was beneficial to improve the catalytic activity of CoP for the catalytic hydrogen evolution of ammonia borane, while the catalytic activity of S-doped CoP for the catalytic hydrogen evolution of ammonia borane is relatively weak. These results reveal the relationship between the physical properties of CoP (and its non-metal-doped variants) and their catalytic activity. Finally, these findings can be used to explain the underlying mechanism reported in previous experimental studies from a microscopic perspective. [ABSTRACT FROM AUTHOR]

Cocatalysts are usually applied in the photocatalytic water splitting process to accelerate the kinetics of the hydrogen evolution reaction (HER). Specifically, the transition metal nitride (Mo2N) featuring a unique local surface plasmon resonance (LSPR) effect has exhibited great potential to function as a HER cocatalyst. However, the low metallicity of Mo2N hampers its ability to improve charge separation. To address this issue, transition metal atom doping (Co and Cu) engineering was used to modulate the electronic structure of Mo2N nanosheets to achieve a higher electrical conductivity and a lower hydrogen adsorption free energy (‖ΔGH*‖), thereby favoring the HER kinetics. Density functional theory (DFT) calculations and experimental results showed that Co-doping and Cu-doping mainly take place at Mo sites in the crystal structure of Mo2N to form stable structures of Co doped Mo2N (Co–Mo2N) and Cu doped Mo2N (Cu–Mo2N). Compared with pristine Mo2N, both Cu–Mo2N and Co–Mo2N demonstrated a much improved cocatalytic effect over g-C3N4 in promoting charge separation, accelerating HER kinetics and enhancing light absorption. The Co–Mo2N with the highest conductivity and lowest ‖ΔGH*‖ illustrated the best cocatalytic effect, and the H2 production performance (367.8 μmol g−1 h−1) of Co–Mo2N/g-C3N4 achieved was 10 and 5 times higher than those of Mo2N/g-C3N4 and Cu–Mo2N/g-C3N4. This paper provides significant guidance in the design and development of efficient cocatalysts for the HER application. [ABSTRACT FROM AUTHOR]

Constructing a suitable heterojunction structure while maintaining a tight interface to promote the separation of photogenerated electrons is of great significance for improving the photocatalytic activity. In this paper, a new PANI/NH2-MIL-101(Fe) II-scheme heterojunction was prepared by a hydrothermal method. PANI with a porous structure was firstly obtained by the template method, and then PANI fragments were loaded on the surface of NH2-MIL-101(Fe) crystals under hydrothermal conditions to obtain a PANI/NH2-MIL-101(Fe) photocatalyst. The photocatalytic degradation of TC under simulated sunlight can reach 90% within an hour, and the maximum hydrogen evolution rate is 7040 μmol g−1 h−1 under visible light. The enhanced catalytic performance of PANI/NH2-MIL-101(Fe) was attributed to the appropriate matching of the VB and CB of PANI and NH2-MIL-101(Fe), and secondly, the coordination bonds formed between PANI and NH2-MIL-101(Fe) provided a channel for charge separation and transfer. Finally, a possible mechanism of the photocatalytic system was proposed through a free radical capture experiment and characterization analysis. More importantly, the experiment proved that the heterojunction formed by PANI and NH2-MIL-101(Fe) can achieve the effect of complementing each other, which provides a feasible idea and method for the design of efficient heterojunction photocatalysts. [ABSTRACT FROM AUTHOR]

Increasing fossil fuel demands and growing concerns of global climate change have stimulated interest in the development of electrocatalysts to produce H2 as an alternative zero-emission fuel from the electrolysis of water via hydrogen evolution reaction (HER). Precious or non-precious catalysts are typically loaded on high surface area carbon materials, and these supports play a critical role in both thermodynamics and kinetics of the HER. In this paper, we evaluate the electrocatalytic activity of a molecular hydrogen evolving catalyst, diacetyl-bis(4-methyl)-3-thiosemicarbazone Ni(II) (Ni-ATSM), on three different carbon surfaces: glassy carbon, carbon paste and pencil graphite. The overpotential for each modified electrode was benchmarked at a current density of −10 mA cm−2. Carbon paste electrodes showed highest overpotentials (495 mV) compared to the other electrode surfaces. Polished pencil and glassy carbon modified electrodes performed similarly (η = 395 mV for GCE and η = 400 mV for pencil). Pencil electrodes etched in acetone overnight prior to Ni-ATSM deposition produced lowest overpotentials (η = 354 mV). Etching results in an increase in electroactive surface area and substantial decrease in the charge transfer resistance of the graphitic interface from 275 Ω to 50 Ω, verified using electrochemical impedance spectroscopy (EIS). Our studies demonstrate pencil graphite may serve as versatile, disposable, cost effective, and reproducible electrode surface for the evaluation of heterogeneous HER catalysts. Moreover, pencils can be easily cut with table saw to generate new surface for easy characterization of the surface such as electrochemistry, imaging and spectroscopy. [ABSTRACT FROM AUTHOR]

Compared with the noble metal Pt, the non-noble metal Cu as a cocatalyst exhibits a low hydrogen-evolution activity owing to its weak Cu–H bond (11 kcal mol−1), which inhibits hydrogen adsorption on Cu atoms for the hydrogen-evolution reaction of photocatalysts. Considering that the introduction of Ni with a strong Ni–H bond into Cu is beneficial for strengthening the H-adsorption ability of Cu, in this paper, the low-cost transition-metal Ni was directly introduced into Cu to form CuNi alloy nanodots as photocatalytic cocatalysts to enhance the hydrogen-evolution rate of TiO2. The CuNi alloy nanodots (2–3 nm) were photodeposited on the surface of a reduced graphene oxide (rGO)-modified TiO2 photocatalyst to generate CuNi-rGO/TiO2 by the pre-adsorption of Cu2+ and Ni2+ ions on graphene oxide (GO). Photocatalytic hydrogen-production data manifested that the CuNi-rGO/TiO2 photocatalyst achieved the highest hydrogen-production rate (10 411 μmol h−1 g−1), which was 53.7, 38.7, 1.8, and 2.2 times higher than that of pure TiO2, rGO/TiO2, Cu-rGO/TiO2, and Ni-rGO/TiO2, respectively. Density-functional-theory (DFT) calculations and mechanistic investigation showed that the introduction of Ni into Cu to form CuNi alloy nanodots improved the H-adsorption ability of Cu and optimized the H-adsorption free energy close to zero (0.046 eV) for boosting the hydrogen production rate of TiO2. This research presents a promising design of bimetallic alloy structures as H2-production cocatalysts for efficient photocatalysts. [ABSTRACT FROM AUTHOR]

While Pt is considered the best catalyst for the electrocatalytic hydrogen evolution reaction (HER), it is evident that non-noble metal alternatives must be explored. In this regard, it is well known that the binding sites for non-noble metals play a pivotal role in facilitating efficient catalysis. Herein, we studied Fe(II) complexes with bidentate 2-(2'-pyridyl)benzoxazole (LO), 2-(2'-pyridyl)benzthiazole (LS), 2-(2'-pyridyl)benzimidazole (LNH), and 2-2'-bipyridyl (Lpy) ligands - by adding trifluoroacetic acid (TFA) to their acetonitrile solution - in order to examine how their reactivity towards protons under reductive conditions could be impacted by the non-coordinating heteroatoms (S, O, N, or none). By applying this ligand series, we found that the reduction potentials relevant for HER correlate with ligand basicity in the presence of TFA. Moreover, DFT calculations underlined the importance of charge distribution in the ligand-based LUMO and LUMO+1 orbitals of the complexes, dependent on the heterocycle. Kinetic studies and controlled potential electrolysis - using TFA as a proton source - revealed HER activities for the complexes with LNH, LO, and LS of kobs = 0.03, 1.1, and 10.8 s-1 at overpotentials of 0.81, 0.76, and 0.79 V, respectively, and pointed towards a correlation between the kinetics of the reaction and the noncoordinating heteroatoms of the ligands. In particular, the activity was associated with the [Fe(LS/O/NH)2(S)2]2+ form (S = solvent or substrate molecule), and the rate-determining step involved the formation of [Fe(H-H)]+, during the weakening of Fe-H and CF3CO2-H bonds, according to the experimental and DFT results. [ABSTRACT FROM AUTHOR]

Efficient hydrogen evolution reaction (HER) electrocatalysts are crucial for renewable energy storage and conversion. Pt remains the most efficient HER catalyst, but its widespread application is hindered by cost and resource constraints. In this study, we investigate the HER electrocatalytic activities of free-metal SiC monolayers through doping and strain engineering. Through density functional theory (DFT) calculations, we explore the effects of B, N, S, and P doping on the HER performance of SiC. Our results reveal that B and P doping enhance the catalytic activity, with P doping showing the most promising activity due to its smaller ΔGH* values. Furthermore, we apply tensile strain to modulate the HER activity of P-doped SiC, achieving further improvements. We also construct composite structures of P-doped SiC with graphene, enhancing conductivity and catalytic performance. Our findings provide valuable insights into tailoring the HER catalytic properties of SiC monolayers, offering a pathway towards sustainable hydrogen production. [ABSTRACT FROM AUTHOR]

In this work, a high density of dispersed Co9S8 nanoparticles (NPs) loaded in carbon aerogels as bi-catalysts (Co9S87.5NP/CA catalysts) were successfully prepared by virtue of the seeded-growth method that is widely used for the synthesis of noble metal NPs. It is found that the optimal molar ratio of Co2+-to-Fe3+ ions for the formation of a high density of dispersed Co9S8 NPs with average sizes of 90 nm is determined to be 7.5 (represented by the superscript number) at the fixed concentration of tannic acid (TA) ([TA] : [Fe3+] = 1 : 1). Moreover, the concentration of Fe3+ precursors is the key that can guarantee the formation of dispersed Co9S8 NPs by the overgrowth of in situ Fe SA-NCs as seeds by the spatial confinement effect during the pyrolysis. Thanks to the multiple valence states of elemental Co in the Co9S8 NPs and their good dispersity in the as-prepared Co9S87.5NP/CA catalysts, the half-wave potential (E1/2) and the overpotential at 10 mA cm−2 (η10) towards the alkaline oxygen reduction reaction (ORR) and the acidic hydrogen evolution reaction (HER) can be improved up to 0.891 V and 177 mV, respectively. [ABSTRACT FROM AUTHOR]

The hydrogen evolution reaction (HER), as a pivotal half-reaction, significantly hinders the advancement of energy conversion efficiency. Metal electrodeposition on catalysts has been demonstrated to effectively enhance the HER reactivity. Here, Ni3S2–Fe–Ni with a multilayer structure was obtained by the electrodeposition of Ni3S2 with dopants Fe/Ni, in which a number of active sites were achieved and the intrinsic conductivity of the catalyst was well improved. Elemental analyses revealed the multilayer structure consisting of Ni3S2, NiS, and Fe. The Ni3S2–Fe–Ni catalyst exhibited impressive electrochemical performance due to optimization of its structure with the overpotentials of the HER and OER of only 83 and 190 mV. Notably, at a higher current density of 100 mA cm−2, the overpotentials for the HER and OER are only 339 and 365 mV. As a bifunctional electrocatalyst, its total splitting voltage was only 1.55 V. The catalysis performance remained nearly unchanged even after 48 h of stability testing. Finally, density functional theory (DFT) calculations revealed that the potential barriers in each reaction step of the OER are evenly distributed, and optimizing the Ni3S2 structure with iron and nickel atoms reduced the reaction energy barriers during the electrochemical process, improving the OER/HER performance. [ABSTRACT FROM AUTHOR]

Cocatalyst loading is of critical importance in efficient photocatalytic water splitting over perovskite oxynitrides. Perovskite CaTaO2N was synthesized for enhancing photocatalytic hydrogen evolution via decoration of a Pt cocatalyst by impregnation–reduction and photodeposition methods. The Pt-loaded CaTaO2N photocatalyst evolves 6.4 μmol H2 per hour, with an apparent quantum yield as high as 0.67% at a wavelength of 420 nm. Decorating the cocatalyst with uniform dispersion and intimate contact onto the surface of narrow-bandgap perovskite oxynitrides is an efficient method to upgrade photocatalytic hydrogen evolution from water splitting. [ABSTRACT FROM AUTHOR]

The pursuit of developing highly potent and environmentally friendly photocatalysts for water dissociation is crucial for the advancement and storage of unlimited solar energy, although it remains a massive challenge. Herein, we conducted a screening process for the photocatalytic water splitting capabilities of a multitude of members from the extensive MA2N4 family. Using first-principles calculations, we found MoSi2N4, WSi2N4 and WGe2N4 structures with excellent potential for photocatalytic applications. To be specific, these members possess semiconductor characteristics, featuring suitable band gap structures and pronounced optical absorption capabilities in the UV-visible light spectrum. Our findings suggest that with nitrogen vacancies present on the surface, MoSi2N4, WSi2N4, and WGe2N4 all demonstrate near-zero Gibbs free energy in driving the hydrogen evolution reaction. Simultaneously, MoSi2N4, WSi2N4, and WGe2N4 can spontaneously catalyze the overall water splitting reaction under light illumination at pH values of 4, 12, and 8, respectively. This investigation provides fresh perspectives in terms of designing highly efficient photocatalysts. [ABSTRACT FROM AUTHOR]

Element doping and construction of heterojunction composites are the most common ways to enhance g-C3N4, which are very attractive in achieving high photocatalytic activity. In this study, 2D nanosheet structured BCN was obtained by doping B atoms with graphite carbon nitride. Subsequently, Ti MOFs were loaded on BCN to obtain a Z-scheme heterojunction composite TBCN through calcination. Under simulated sunlight, the photocatalytic hydrogen production rate of the TBCN heterostructure was 1242 μmol h−1 g−1, which was 2.2 times higher than that of BCN and 9.34 times higher than that of bulk graphite carbon nitride (GCN). Experimental results showed that the construction of a Z-scheme heterojunction composite (TBCN) could effectively adjust the material band gap position, expand the light absorption range, enhance electron transfer and inhibit electron–hole recombination, which are crucial for efficient photocatalysis. This study not only provides a strategy for constructing heterojunction composites in the field of g-C3N4 photocatalytic hydrogen evolution, but also deeply analyzes the electron migration direction and the reasons for enhancing carrier separation in the Z-type heterojunction scheme, thus providing potential guidance for future research. [ABSTRACT FROM AUTHOR]

Covalent triazine frameworks (CTFs) containing S heteroatom are promising materials for applications in photocatalysis due to their donor–acceptor-type structures, which can improve the mobility of carriers in polymers. Herein, a series of composites (TTBT-COF@PEGx, x = 10, 20, and 30) were prepared based on CTF containing S heteroatom and polyethylene glycol (PEG) by a two-step reaction. The results show that the photocatalytic hydrogen evolution rate of TTBT-COF@PEG30 is 1.51 times that of pristine TTBT-COF. This significant improvement was attributed to PEG in the pores, which resulted in a stable layered structure, reuced distortion and deformation of the skeleton, and rapid separation and transportation of photogenerated electron holes. [ABSTRACT FROM AUTHOR]

The strategies for optimizing the morphology/structure and regulating the active sites of materials are effective ways to improve their electrocatalytic performance in the hydrogen evolution reaction (HER) and electrooxidation reaction. Herein, we demonstrate a facile strategy for constructing a NiO/NiCo2O4 porous nanowire catalyst on nickel foam (NiO/NiCo2O4/NF) as a bifunctional electrocatalyst to enhance the electrocatalytic performance for coupling the HER with the glucose oxidation reaction (GOR). Benefiting from the unique 1D porous nanowire structure and enhanced interfacial synergistic effect of the bicomponent catalyst, optimized NiO/NiCo2O4/NF-300 exhibited remarkable electrocatalytic activities for the GOR and HER with low potentials of 1.128 V and 0.212 V, respectively, at 100 mA cm−2. Moreover, the GOR exhibited a high yield of 72% for formic acid. This study provides a promising and simple strategy for the construction of 1D NiO/NiCo2O4 porous nanowire electrocatalysts with rich heterogeneous interfaces and paves a facile pathway for accelerating biomass electrochemical reaction-assisted hydrogen production. [ABSTRACT FROM AUTHOR]

The photocatalytic hydrogen evolution half-reaction (HER) is a promising technology for meeting future energy demands. An excellent photocarrier separation is essential for the HER. Here, a CdS/ZnS composite (CZS) with a dual photocarrier separation channel has been synthesized using the epitaxial growth method to achieve this aim. XRD and TEM show that pre-adsorption of S2− on the CdS surface facilitates the conversion of CdS into ZnS with a larger solubility product, implying a good carrier transport channel between CdS and ZnS. Based on XPS, PL, and photo-deposition experiments, a dual-channel photocarrier separation mechanism has been proposed, which is the source of the great photocarrier separation, and thus the hydrogen evolution rate of the CZS-2 sample (22.05 mmol g−1 h−1) becomes 18.5 and 73.5 times higher than those of CdS and ZnS. The apparent quantum yield (AQY) of CZS-2 at 420 nm is 4.68%. [ABSTRACT FROM AUTHOR]