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The synergistic effects derived from optimizing the chemical and structural features of electrocatalysts permit them to attain remarkable activity and stability. Herein, 1D/2D cobalt‐based nanohybrid (CoNH) electrodes are developed; the structural design consists of Co3O4 electrospun nanoribbons (NRs) deposited onto a carbon fiber paper substrate where Co3O4 nanosheets are subsequently grown via an electrodeposition step and UV/ozone treatment. The content of noncovalently functionalized carbon nanotubes within the Co3O4 NRs is first tuned to enhance their charge transfer properties and mechanical stability. The electrocatalytic activity of the electrodes is further improved by a phosphorus modification of the 1D NRs, resulting in the formation of NaCoPO4. The optimized 1D/2D CoNH electrode, i.e., ED‐0.09 wt% fCNTs/P‐CoNHs, displays a similar performance to that of platinum in 0.25 m Na2S/0.35 m Na2SO3 (Tafel slope ≈102 mV dec−1 for the former and ≈96 mV dec−1 for the latter) and outstanding stability for up to 48 h. The versatility and high activity of this electrode is also demonstrated according to tests in a conventional water splitting system (cell voltage 1.55V, to produce 10 mA cm−2) and a solar‐driven electrolyzer (1 m KOH). [ABSTRACT FROM AUTHOR]

Herein, a new energy cycle called the "hydrogen iodide (HI) cycle" is proposed that involves the repeated generation of solar hydrogen and battery power. Solar hydrogen generation using an HI solution allows for the use of a narrow‐bandgap photocatalyst. It is demonstrated that the addition of single‐walled carbon nanotubes (SWCNTs) effectively enhances solar hydrogen generation from HI solution with methylammonium lead iodide. Electron microscopy observations and spectroscopic experiments reveal that SWCNTs improve hydrogen generation by adsorbing byproduct iodine molecules. Additionally, a zinc‐iodine battery, utilizing paper I@SWCNTs recovered from the photocatalyst test cell and zinc metal, operates efficiently with an initial cell voltage of approximately 1.2 V. The battery's capacity, corresponding to the amount of encapsulated iodine molecules, indicates that SWCNTs can effectively adsorb the byproduct iodine molecules within the photocatalyst test cell. It is also discussed that the electrolyte solution after the discharge experiment should include iodide ions, indicating that the solution after battery discharge returns to the starting point of the "HI cycle." Raman measurements reveal that I@SWCNTs are transformed back into empty tubes during the discharge experiment. Therefore, SWCNTs can be repeatedly used in the new cyclic energy scheme referred to as the "HI cycle." [ABSTRACT FROM AUTHOR]

In the pursuit of sustainable hydrogen production via water electrolysis, paramount importance of electrocatalyst stability emerges as a defining factor for long‐term industrial viability. A thorough understanding and enhancement of stability not only ensure extended catalyst lifetimes but also pave the way for consistent and efficient hydrogen generation. This review focuses on the pivotal role of stability in determining the practical viability of oxygen evolution electrocatalysts (OECs) for large‐scale applications in water electrolysis for hydrogen production. The paper explores the pivotal role of stability over initial activity, citing examples and hypothetical scenarios. First, figures of merits for stability evaluation of the electrocatalyst are explained along with the available benchmarking protocols for stability evaluation. Further, the text delves into various strategies that can enhance the stability of the electrocatalyst which include self‐healing/regeneration pathway, oxygen evolution reaction (OER) mechanism optimization to achieve highly stable OER and stabilization of active metals atoms within the electrocatalyst to inhibit dissolution as a way forward for industrial application. The interplay of stability, activity, and cost is also explained to suit the industrial application of the electrocatalyst. Lastly, it outlines challenges, prospects, and future directions, presenting a guide for advancing OECs in the hydrogen generation landscape. [ABSTRACT FROM AUTHOR]

Construction of a "net‐zero‐emission" system through CO2 hydrogenation to methanol with solar energy is an eco‐friendly way to mitigate the greenhouse effect. Traditional CO2 hydrogenation demands centralized mass production for cost reduction with mass water electrolysis for hydrogen supply. To achieve continuous reaction with intermittent and fluctuating flow of H2 on a small‐scale for distributed application scenarios, modulating the catalyst interface environment and chemical adsorption capacity to adapt fluctuating reaction conditions is highly desired. This paper describes a distributed clean CO2 utilization system in which the surface structure of catalysts is carefully regulated. The Ni catalyst with unsaturated electrons loaded on In2O3 can reduce the dissociation energy of H2 to overcome the slow response of intermittent H2 supply, exhibiting a faster response (12 min) than bare oxide catalysts (42 min). Moreover, the introduction of Ni enhances the sensitivity of the catalyst to hydrogen, yielding a Ni/In2O3 catalyst with a good performance at lower H2 concentrations with a 15 times adaptability for wider hydrogen fluctuation range than In2O3, greatly reducing the negative impact of unstable H2 supplies derived from renewable energies. [ABSTRACT FROM AUTHOR]

Hydrogen is a strong candidate for fueling the green energy transition. Hydrogen, like all stores of potential energy, can be dangerous if not handled properly. The most common, and rapidly growing, source of green hydrogen is electrolysis of water. Electrolyzers split the water molecule into hydrogen and oxygen molecules. Hydrogen is flammable while oxygen is an oxidizer. If hydrogen escapes, a hazardous condition can be generated, which may have significant safety consequences. As a result, a commonly employed safeguard is a gas detection system with automatic shutdowns. This paper presents an overview of the hazards of hydrogen generation through electrolysis, and then presents a case study of the design of a gas detection system for an electrolyzer facility. The design of the gas detection system included using gas detection mapping approaches recommended by ISA TR 84.00.07 for placement of the required detectors along with recommendations by IEC 61511 for the design of the associated automatic shutdown of the electrolyzer and return to a safe state. [ABSTRACT FROM AUTHOR]

Photocatalytic water splitting to obtain hydrogen energy can transform low‐density solar to high density, new and clean energy in a clean way, which is one of the ideal ways to solve the energy crisis and environmental pollution. In this paper, The CoxP/hollow porous C3N4 composite photocatalytic material was synthesized by simple methods. The photocatalytic hydrogen production rate of CoxP/hollow porous C3N4 reaches 1602 μmol g−1 h−1, which is 151 times of that of pure C3N4. The reasons for the high photocatalytic H2 evolution activity of CoxP/hollow porous C3N4 could be summarized as follows: (1) the hollow and porous structure of C3N4 shows higher light capture efficiency, larger specific surface area and more surface active sites. (2) metalloid CoxP loaded forms the Schottky contact with C3N4, which improves the photogenerated charges separation efficiency of C3N4, prolongs the photogenerated charges lifetime and improves the photocatalytic H2 evolution activity of C3N4. (3) The higher conductivity of metalloid CoxP and the lower overpotential of hydrogen production are other reasons for the higher activity of photocatalytic hydrogen production of CoxP/hollow porous C3N4. This work provides an important role for the design of efficient, stable, and efficient construction of photocatalysts for solar energy conversion. [ABSTRACT FROM AUTHOR]

Hydrogen gas is a prominent focus in pursuing renewable and clean alternative energy sources. The quest for maximizing hydrogen production yield involves the exploration of an ideal photocatalyst and the development of a simple, cost‐effective technique for its generation. Iron titanate has garnered attention in this context due to its photocatalytic properties, affordability, and non‐toxic nature. Over the years, different synthesis routes, different morphologies, and some modifications of iron titanate have been carried out to improve its photocatalytic performance by enhancing light absorption in the visible region, boosting charge carrier transfer, and decreasing recombination of electrons and holes. The use of iron titanate photocatalyst for hydrogen evolution reaction has seen an upward trend in recent times, and based on available findings, more can be done to improve the performance. This review paper provides a comprehensive overview of the fundamental principles of photocatalysis for hydrogen generation, encompassing the synthesis, morphology, and application of iron titanate‐based photocatalysts. The discussion delves into the limitations of current methodologies and present and future perspectives for advancing iron titanate photocatalysts. By addressing these limitations and contemplating future directions, the aim is to enhance the properties of materials fabricated for photocatalytic water splitting. [ABSTRACT FROM AUTHOR]

The hydrogen production from natural gas has advantages of low investment, low carbon emission, and high hydrogen production rate. This paper briefly describes the technical overview of hydrogen production from natural gas reforming and identifies its risk factors. According to the dangerous characteristics of high reaction temperature, easy leakage of reaction medium, flammability, and explosion in the process, the intrinsic safety of the process is discussed in combination with relevant research and industrial experience. The safety requirements of key equipment and materials are introduced in detail, followed by the optimization methods of process safety that can be taken in the engineering process. Besides, the accident prevention measures for emergency shutdown and fire explosion are summarized. Finally, the future research demands are put forward from the perspective of research and development, which is instructive for the safe hydrogen production from natural gas in the future. [ABSTRACT FROM AUTHOR]

Natural cellulose substances have been proven to be ideal structural templates and scaffolds for the fabrication of artificial functional materials with designed structures, psychochemical properties and functionalities. They possess unique hierarchically porous network structures with flexible, biocompatible, and environmental characteristics, exhibiting great potentials in the preparation of energy‐related materials. This minireview summarizes natural cellulose‐based materials that are used in batteries, supercapacitors, photocatalytic hydrogen generation, photoelectrochemical cells, and solar cells. When natural cellulose substances are employed as the structural template or carbon sources of energy materials, the three‐dimensional porous interwoven structures are perfectly replicated, leading to the enhanced performances of the resultant materials. Benefiting from the mechanical strengths of natural cellulose substances, wearable, portable, free‐standing, and flexible materials for energy storage and conversion are easily obtained by using natural cellulose substances as the substrates. [ABSTRACT FROM AUTHOR]

The ionic liquid (IL) 1‐octyl‐3‐methylimidazolium bromide/FeCl3 [OMIM]Br/FeCl3 was prepared with three molar ratios of [OMIM]Br/FeCl3 (0.5 : 1, 1 : 1, and 2 : 1), and fully characterized through 1H and 13C NMR, Fourier‐transform IR, and Raman spectroscopic techniques. The optical properties of the prepared [OMIM]Br/FeCl3 ILs were revealed via diffuse reflectance and photoluminescence spectra. The photocatalytic activity of [OMIM]Br/FeCl3 ILs as homogenous photocatalysts were investigated towards hydrogen generation from methanol/water mixtures under visible light irradiation. The FeCl3‐based IL with [OMIM]Br/FeCl3 molar ratio of 1 : 1 exhibited the highest visible light photocatalytic activity with a hydrogen productivity of 243.2 mmol h−1 g−1 and a hydrogen purity of 95.5 %; such a high hydrogen yield and purity was reported for the first time. It was proposed that [OMIM] Br acted as an electron acceptor, which delayed the electron‐hole pair recombination of FeCl3. Also, [OMIM] Br could capture the produced carbon dioxide that is released with hydrogen gas. Additionally, [OMIM] Br/FeCl3 could be reused six times with nearly the same photocatalytic activity. These outstanding credits in terms of hydrogen generation rate and purity plus the economic feasibility, through several cycles of reuse, could certify such an IL as a promising photocatalyst for employment in water splitting. This paper suggests ways forward for research to develop the use of ILs as efficient and effective photocatalysts for hydrogen generation via water splitting. [ABSTRACT FROM AUTHOR]

In this paper, the properties and evolution during the calcination process of hydrolysis by−products from the reaction between Al−based composites and water for hydrogen generation were systematically investigated. The results showed that the main phases of by−products included AlOOH and InSn4. The amorphous product possessed a large Brunauer−Emmett−Teller (BET) surface area with 276.77 m2/g and high porosity properties with 0.37 cm3/g. The phase transformation of by−products from AlOOH to γ−Al2O3, δ−Al2O3, and α−Al2O3 occurred during the calcination process. It appears that the by−products can be used as raw materials for the preparation of Al2O3 with different crystal structures. Discussion on the properties and evolution of hydrolysis by−products are beneficial to product reuse and recovery. In this way, the cost reduction of hydrogen production via Al−water reaction can be realized, promoting the sustainable development of hydrogen production from Al−water reaction. [ABSTRACT FROM AUTHOR]

In this paper, density functional theory (DFT) was used to study the reaction mechanism of the production of hydrogen peroxide from oxygen and water catalyzed by graphene supported metal (Al, Zn, and Fe) catalysts. By comparing the supported stability of metal at different sites on graphene surface, the optimal support sites are determined and then a stable catalyst model is selected. Two different reaction paths for the synthesis of hydrogen peroxide and a competitive reaction path for the generation of hydrogen are discussed, the microscopic reaction mechanism of the synthesis of hydrogen peroxide catalyzed by water and oxygen is investigated in detail. The stable structures of reactants, intermediates, and products in each path are optimized. By comparing the activation energies of different reaction paths, the optimal reaction paths are obtained, and the possibility of side reaction products is predicted. At the same time, the electron density, band structure, and density of states characteristics of these graphene supported metal catalysts are studied. The correlation between the physical properties of the three catalysts and their catalytic performances is analyzed. It is predicted that Al, Zn, and Fe catalysts supported by graphene may have the ability to directly generate hydrogen peroxide in industrial wastewater treatment. [ABSTRACT FROM AUTHOR]

Due to the amendment of sewage sludge ordinance in Germany, phosphorus must be recovered from sewage sludge in the future. Previously developed phosphorus recycling processes are not economically viable due to high material and energetic expenditures. Gasification of dried sewage sludge enables the energetic utilization of sewage sludge and provides the energy for phosphorus recovery. The present paper focuses on thermodynamic modeling of the gasification system to demonstrate the potential for holistic utilization of dried sewage sludge as phosphorus fertilizer. The results shows that an energy self‐sufficient, optimized process can be realized for recovery of phosphorus by gasification and subsequent thermo‐chemical treatment of dried sewage sludge. [ABSTRACT FROM AUTHOR]

Inadvertent generation of hydrogen from ambient temperature metal‐water chemical and electrochemical reactions have been responsible for a surprising number of hydrogen explosions. This paper describes three sets of incidents involving different metals in applications that are normally considered free of explosion hazards. The first set of incidents involves wet alkaline incinerator ash with an aluminum content of at least 2%. The second set of incidents involves copper conductor electrochemical reactions in subsea electrical cable. The third set involves electrochemical corrosion reactions in galvanized dry sprinkler pipe. In all three applications, test data are discussed to elucidate the specific reactions and potential preventive and mitigation measures. [ABSTRACT FROM AUTHOR]

As a new 2D carbon hybrid material, graphdiyne has attracted much attention due to its good conductivity, adjustable electronic structure, and special electron transfer enhancement properties. It has great potential in the field of hydrogen evolution by photocatalytic water splitting due to its special properties. In this paper, layered graphdiyne is prepared by crosscoupling method, using CuI instead of typical copper film as catalyst. Graphdiyne/CuI is used to modify Mn0.2Cd0.8S (MCS) solid solution for the first time, which greatly improves the optical properties and hydrogen production performance of the photocatalyst. The S‐scheme heterojunction constructed between graphdiyne and MCS greatly improves the transfer rate of photoinduced electrons. In addition, the results of fluorescence spectra and photoelectrochemical tests show that the nanocomposites have longer carrier lifetime, lower recombination rate, faster carrier migration rate, and lower hydrogen evolution overpotential. Therefore, the hydrogen evolution rate of the MnCdS/graphdiyne/CuI with the best performance can reach 9.904 mmol g−1 h−1, which is 4.02 times of that of pure MCS. This work not only proposes the possible mechanism of photocatalytic hydrogen production but also provides an important strategy for the application of graphdiyne in the field of photocatalytic hydrogen production. [ABSTRACT FROM AUTHOR]

Chemical hydrogen storage ammonia borane has attracted extensive attention as a method of efficient utilization of hydrogen energy. The high‐efficiency catalysts are the main factor restricting the hydrogen production of ammonia borane. In this paper, the synergistic effect of Co and CoOx supported on graphene (named Co−CoOx@GO‐II) promotes the efficient hydrogen production of ammonia borane, and its catalytic hydrogen production rate can reach 5813 mL min−1 gCo−1 at 298 K, the corresponding TOF is 15.33 min−1. After five stability tests, Co−CoOx @GO‐II maintained 65% of its original catalytic performance. The synergy of metal and metal oxide and the defects in the atomic arrangement ensure the catalytic activity, the large specific surface area of graphene ensures the dispersion and fixation. This strategy may provide a possibility to design high‐performance transition metal catalysts. [ABSTRACT FROM AUTHOR]

This paper presents the modeling and energy management system (EMS) of a hybrid marine‐hydrogen power generation system. The proposed system aims to convert the static nature of the tidal energy into an active system by using a hydrogen energy storage system. The system of the tidal energy converter (TEC) considers the fixed pitch direct drive technology while the hydrogen system consists of 1.0 MW (megawatt) proton exchange membrane electrolyzer. A MATLAB/Simulink based model has been developed for studying and evaluating the effectiveness of the proposed EMS. The developed model depends on scaling up a 50 W proton exchange membrane (PEM) electrolyzer model to 1 MW scale by adapting the model parameters for providing the same key performance indicators (KPIs). The EMS aims to convert all the TEC generated energy into hydrogen with considering the efficient and safe operation of the different system components. Thus, the loss minimization (efficiency maximization) of the tidal turbine generator is integrated as one of the EMS goals to evaluate its effect on hydrogen production. The generator of the TEC is controlled by two different strategies for estimating the surplus hydrogen that could be produced. The strategies are the maximum torque/ampere and the loss minimization. [ABSTRACT FROM AUTHOR]

Waste organic biomass is regarded as the most suitable renewable source for conversion to produce biofuels and biochemicals. Owing to its high‐energy potential and abundancy, lignocellulosic biomass can be utilized to produce alternative energy in the form of gaseous and liquid biofuels. Microbial conversion of waste biomass is the most successful technology for the generation of biohydrogen through dark fermentation. Different biological hydrogen production technologies along with process parameters are described in this review paper with the focus on dark fermentation. The production of biohydrogen from various substrates is summarized along with the integrated mode of dark fermentation and photofermentation. Hydrogen generation through biological water‐gas shift reaction is also highlighted. [ABSTRACT FROM AUTHOR]

Novel phase of nano materials that break the traditional structural constraints are highly desirable, particularly in the field of mechanocatalysis, offering versatile applications ranging from energy to medical diagnosis and treatment. In this work, a distinct layered barium dititanate (BaTi2O5) nanocrystals using a pH‐modulated hydrothermal method is successfully synthesized. These nanocrystals exhibit outstanding hydrogen generation capability (1160 µmol g−1 h−1 in pure water) and demonstrate remarkable performance in organic dye degradation using ultrasonication. The crystal structure of this newly discovered BaTi2O5 phase, is determined by a combination of synchrotron Powder Diffraction refinement and X‐ray adsorption techniques, including X‐ray Absorption Near Edge Structure (XANES) and Extended X‐ray Absorption Fine Structure (EXAFS). Density Functional Theory calculations revealed that the newly‐discovered BaTi2O5 phase demonstrates dipole moments along the z‐axis, distributed in an antiparallel direction within a single unit cell. These inherent dipoles induce a surface polarization and a ferroelectric‐flexoelectric response under mechanical stimuli when the materials go to nano dimension. With a band alignment well‐suitable for hydrogen and reactive oxygen species generation, this BaTi2O5 phase demonstrates promising potential for Mechanocatalysis. The discovery of this distinct phase not only enriches the material candidates for mechanocatalysis but also provides valuable insights. [ABSTRACT FROM AUTHOR]

In this review, the transformative role of polymer nanocomposites in hydrogen production from challenging water sources is explored. Their catalytic efficiency and unique properties are highlighted, making them vital for overcoming complexities in hydrogen generation. Polymer nanocomposites demonstrate exceptional adaptability to various water compositions, including wastewater and saline water, enhancing efficiency, stability, and compatibility. In this review, the significance of these nanomaterials in the sustainable energy landscape is underscored, showcasing their ability to outperform conventional methods. Key breakthroughs in catalytic efficiency and adaptability are emphasized, illustrating their crucial role in clean hydrogen production. Looking forward, in this review, potential applications of polymer nanocomposites in diverse fields, from industrial processes to energy sector advancements, are identified. This synthesis of findings not only enhances the understanding but also sets the stage for the widespread adoption of polymer nanocomposites in meeting the global demand for sustainable hydrogen production. [ABSTRACT FROM AUTHOR]

Transition metal dichalcogenides (TMDs) have garnered attention as potential catalysts for water splitting owing to their unique structures, diverse electronic properties, and composition from earth‐abundant elements. While certain TMD catalysts, notably MoS2, have shown promising activity for hydrogen evolution reactions (HER), achieving performance comparable to traditional platinum catalysts remains a challenge. While significant effort has been invested into understanding the effect of TMD's structural properties, such as defectiveness and crystalline phases, recent work has emphasized the role of extrinsic factors on HER. This review summarizes the current understanding of the impact of commonly overlooked electrocatalytic effects that exhibit an enhanced importance in TMD‐based HER. By combining recent advances in theoretical modeling and experimental work, we review the dominating effects of extrinsic factors including electronic resistance, interfacial barriers, surface roughness, oxidation, and valence impurities. Our work aims to provide insights into optimizing TMDs as highly efficient catalysts for HER, facilitating future advancements in hydrogen generation technology. [ABSTRACT FROM AUTHOR]

The application of formic acid (FA) as a safe, renewable and promising hydrogen‐storage material has received considerable attention. However, exploring efficient heterogeneous catalysts for selective dehydrogenation of FA remains a challenging topic. In this paper, a super nanoteragonal ZrO2(The crystallite size reached even 150 nm) is synthesized by calcining Zr‐based metal‐organic framework. Because the unique microstructures of the material which possess the electron‐rich property and surface basicity, the resulting PdAg@ZrO2/C catalyst exhibits excellent activity (Turnover frequency 9206 h−1 at 50 °C) for the decomposition of FA. These results may contribute to the design of efficient catalysts for dehydrogenation of FA and extended applications of tetragonal zirconia polycrysta without the dopants or reduction of the crystallite size. A super nanoteragonal ZrO2 was found in our research. The unique microstructures of the material which possess the electron‐rich property and surface basicity, the resulting PdAg@ZrO2/C catalyst exhibits excellent activity (Turnover frequency 9206 h−1 at 50 °C) for the decomposition of FA. [ABSTRACT FROM AUTHOR]

Our group has developed a series of molecular electrocatalysts for hydrogen generation based on triazenido–metal complexes (cobalt, copper, etc.). In this paper, we first present the electrocatalytic performance of a new dinuclear silver complex, [Ag2(L)2], formed by the reaction of the triazenido ligand 1‐[(2‐carboxymethyl)benzene]‐3‐[(2‐methoxy)benzene]triazene (HL) with AgNO3. At room temperature, the silver complex shows photoluminescence at 653 nm. The electrocatalytic systems based on this silver complex can afford 106.57 and 1536.36 moles of hydrogen per mole of catalyst per hour from acetic acid at an overpotential (OP) of 991.6 mV and from a neutral aqueous buffer (pH = 7.0) at an OP of 837.6 mV, respectively. Electrochemical investigations show that both silver ion and triazenido ligand play a role in determining the catalytic activities of the electrocatalytic system. [ABSTRACT FROM AUTHOR]

Hydrogen (H2) has emerged as a clean and versatile energy carrier to power a carbon‐neutral economy for the post‐fossil era. Hydrogen generation from low‐cost and renewable biomass by virtually inexhaustible solar energy presents an innovative strategy to process organic solid waste, combat the energy crisis, and achieve carbon neutrality. Herein, the progress and breakthroughs in solar‐powered H2 production from biomass are reviewed. The basic principles of solar‐driven H2 generation from biomass are first introduced for a better understanding of the reaction mechanism. Next, the merits and shortcomings of various semiconductors and cocatalysts are summarized, and the strategies for addressing the related issues are also elaborated. Then, various bio‐based feedstocks for solar‐driven H2 production are reviewed with an emphasis on the effect of photocatalysts and catalytic systems on performance. Of note, the concurrent generation of value‐added chemicals from biomass reforming is emphasized as well. Meanwhile, the emerging photo‐thermal coupling strategy that shows a grand prospect for maximally utilizing the entire solar energy spectrum is also discussed. Further, the direct utilization of hydrogen from biomass as a green reductant for producing value‐added chemicals via organic reactions is also highlighted. Finally, the challenges and perspectives of photoreforming biomass toward hydrogen are envisioned. [ABSTRACT FROM AUTHOR]

Photoelectrochemical (PEC) hydrogen generation is a promising technology for green hydrogen production yet faces difficulties in achieving stability and efficiency. The scientific community is pushing toward the development of new electrode materials and a better understanding of the underlying reactions and degradation mechanisms. Advances in photocatalytic materials are being pursued through the development of heterojunctions, tailored crystal nanostructures, doping, and modification of solid‐solid and solid‐electrolyte interfaces. Operando and in situ techniques are utilized to deconvolute the charge transfer mechanisms and degradation pathways. In this review, both materials development and Operando characterization are covered for advancing PEC technologies. The recent advances made in the PEC materials are first reviewed including the applied improvement strategies for transition metal oxides, nitrites, chalcogenides, Si, and group III‐V semiconductor materials. The efficiency, stability, scalability, and electrical conductivity of the aforementioned materials along with the improvement strategies are compared. Next, the Operando characterization methods and cite selected studies applied for PEC electrodes are described. Operando studies are very successful in elucidating the reaction mechanisms, degradation pathways, and charge transfer phenomena in PEC electrodes. Finally, the standing challenges and the potential opportunities are discussed by providing recommendations for designing more efficient and electrochemically stable PEC electrodes. [ABSTRACT FROM AUTHOR]

Green hydrogen fuel generation via the photoelectrochemical (PEC) approach has attracted considerable attention recently for its sustainability and eco‐friendliness. Photoelectrocatalysts are the key component of the PEC process. To produce green hydrogen by this approach at a reasonable rate from water splitting and waste valorization, proper design and electronic structure modulation of the photoelectrocatalysts are of utmost importance. Therefore, in this review, we discuss the materials selection, design, and engineering of photoanode materials to efficiently harvest and convert solar energy into green hydrogen fuel and value‐added chemicals. In this regard, we introduce the fundamentals and the mechanistic insights of the PEC solar energy conversion and storage technologies, which would provide knowledge to novices to gain insight into this field while designing a new photoanode. Moreover, we mention the importance of various semiconducting materials and their surface/interface engineering aspects to improve the PEC properties for selective water oxidation to value‐added chemicals and waste valorization coupled with green hydrogen generation. Finally, we discuss the conclusions and prospects of this technology by highlighting the major challenges and its potential for commercialization. [ABSTRACT FROM AUTHOR]

A highly efficient, stable, easily recyclable carbon‐based [g‐C3N4/C]//[TiO2/C] Janus nanofibers heterostructure photocatalyst (gT‐JNHP) was first designed and constructed through the combination of conjugative electro‐spinning with subsequent calcination procedure. gT‐JNHP with novel Janus structure consists of two sides: one side is g‐C3N4/C nanofiber that absorbs visible light (VL), and the other side is TiO2/C nanofiber that can capture ultraviolet light (UL), and the two strands of nanofibers are tightly combined together to form the unique heterostructure Janus nanofiber, which can make full use of sunlight (SL). gT‐JNHP presents better remarkably boosted photocatalytic performance in comparison with the counterpart g‐C3N4/C, TiO2/C, or their mechanical mixture, and the degradation efficiencies of methylene blue in gT‐JNHP‐2, respectively, are 95.1% (160 min) and 98.6% (140 min), as well as hydrogen evolution rates reach up to 12.40 and 16.72 mmol h–1 g–1 under VL and simulated SL, respectively, thereby displaying the excellent dual functions of high‐efficient hydrogen release and removal of organic contaminant. The outstanding photocatalytic property is ascribed to the joint effect among the unique Janus‐typed heterostructure, catalyst components, and electrically conductive carbon fiber, achieving close contact between the interfaces, effective separation of photo‐excited carriers, strong light capture ability, and many more exposed active sites, etc. Feasible photocatalytic mechanisms are advanced. Moreover, gT‐JNHP owns the characteristics of flexible self‐standing, easy recycling, and superb durability. The constructing mechanisms of Janus nanofibers and gT‐JNHP are discussed in detail, and the novel fabricating techniques are established. The designing idea and construction techniques adopted in this paper are popularized for research and development of other peculiar uni‐dimensional dual‐functional nanofibrous photocatalysts. [ABSTRACT FROM AUTHOR]

The first Pd2+ containing polyoxoniobate [Pd(cyclam)]5{H3Nb6O19}2 ⋅ 26H2O (I) was prepared at room temperature. In the structure, two hexaniobate clusters are surrounded by a bi‐capped cube formed by Pd2+ centered complexes. This motif is arranged in a layer‐like fashion with crystal water molecules located between cations and anions. Temperature resolved in‐situ X‐ray diffraction experiments demonstrate that successive removal of the crystal water molecules leads to formation of several crystalline intermediate phases. Water sorption investigations show that thermally removed H2O can be successfully reintegrated proceeding via two distinct steps. The catalytic performance for the light‐driven hydrogen evolution reaction (HER) was investigated in a sacrificial system and fluorescein Na+ salt as sensitizer yielding a high value of 90 μmol/h H2. Surprisingly, a composite Pd@Na7[HNb6O19] ⋅ 15H2O is in‐situ formed during the catalytic reaction by cation exchange with simultaneous reduction of Pd2+ nanoparticles decorating the hexaniobate support. The recovered catalyst was even more active producing 157 μmol/h H2 with an apparent quantum efficiency of 1.85 %. Photocatalytic experiments performed with ex‐situ generated Pd nanoparticles deposited on Na7[HNb6O19] ⋅ 15H2O show much lower activities indicating a synergistic effect of the in‐situ generated Pd@Na7[HNb6O19] ⋅ 15H2O catalyst. [ABSTRACT FROM AUTHOR]

Vacancy defects engineering is a valid strategy to enhance the separation efficiency of photo‐generated charges. Herein, a zinc vacancy mediated S‐scheme ZnCdS/ZnS composite derived from ZnCdS/MOF‐5 was constructed in‐situ through the sacrificial reagent of Na2S/Na2SO3 aqueous solution in visible‐light irradiation. The MOF‐5 converted to ZnS (ZnS−VZn) with abundant zinc vacancies which were proved by the XPS and PL results. ZnS−VZn has two‐photon absorption performance, which immensely enhanced the visible light absorption capacity for the photocatalysts. The photo‐generated electrons of ZnS−VZn on the Zn‐vacancy defect would regroup with the holes in the valence band (VB) of ZnCdS via ohmic contact which is induced by Zn‐vacancy defects. Therefore, the photoexciton of ZnCdS can be able to separate effectively and eliminate the useless electrons and holes. The ZnCdS/ZnS(20) sample revealed an outstanding photocatalytic hydrogen generation rate of 12.31 mmol h−1g−1 with a turnover number (TON) of 64.61, which is about 82.06 and 21.98 times greater than that of neat ZnS−VZn and ZnCdS. This work gives an insight into the design of the zinc vacancy‐engineered S‐scheme photocatalyst of ZnCdS/ZnS for highly efficient photocatalysis. [ABSTRACT FROM AUTHOR]

We present the fabrication of core‐shell‐satellite Au@SiO2‐Pt nanostructures and demonstrate that LSPR excitation of the core Au nanoparticle can induce plasmon coupling effect to initiate photocatalytic hydrogen generation from decomposition of formic acid. Further studies suggest that the plasmon coupling effect induces a strong local electric field between the Au core and Pt nanoparticles on the SiO2 shell, which enables creation of hot electrons on the non‐plasmonic‐active Pt nanoparticles to participate hydrogen evolution reaction on the Pt surface. In addition, small SiO2 shell thickness is required in order to obtain a strong plamon coupling effect and achieve efficient photocatalytic activities for hydrogen generation. [ABSTRACT FROM AUTHOR]

In the field of photocatalysis, building a heterojunction is an effective way to promote electron transfer and enhance the reducibility of electrons. Herein, the S‐scheme heterojunction photocatalyst (CoS2/Zn0.5Cd0.5S) of CoS2 nanospheres modified Zn0.5Cd0.5S solid solution was synthesized and studied. The H2 evolution rate of the composite catalyst reached 25.15 mmol g−1 h−1, which was 3.26 times that of single Zn0.5Cd0.5S, whereas pure CoS2 showed almost no hydrogen production activity. Moreover, CoS2/Zn0.5Cd0.5S had excellent stability and the hydrogen production rate after six cycles of experiments only dropped by 6.19 %. In addition, photoluminescence spectroscopy and photoelectrochemical experiments had effectively proved that the photogenerated carrier transfer rate of CoS2/Zn0.5Cd0.5S was better than CoS2 or Zn0.5Cd0.5S single catalyst. In this study, the synthesized CoS2 and Zn0.5Cd0.5S were both n‐type semiconductors. After close contact, they followed an S‐scheme heterojunction electron transfer mechanism, which not only promoted the separation of their respective holes and electrons, but also retained a stronger reduction potential, thus promoting the reduction of H+ protons in photocatalytic experiments. In short, this work provided a new basis for the construction of S‐scheme heterojunction in addition to being used for photocatalytic hydrogen production. [ABSTRACT FROM AUTHOR]

Photocatalytic hydrogen evolution is a promising method to convert solar energy. Here, the heterojunction structure of g‐C3N4/CdS was modified by NiCoP prepared by one‐step method for the first time, and the photocatalyst NiCoP‐g‐C3N4/CdS was successfully designed and prepared, which can effectively separate and transfer photogenerated electrons and efficient hydrogen evolution under visible light. Moreover, NiCoP‐g‐C3N4/CdS photocatalyst has abundant surface‐active sites, and its photocatalytic hydrogen evolution performance has been greatly improved. When NiCoP content was 5 % in NiCoP‐g‐C3N4/CdS, the catalytic activity was the highest, and the hydrogen production rate reached an astonishing 55.63 mmol h−1 g−1, which was 23.35 times that of CdS (2.38 mmol h−1 g−1) and 11.51 times that of g‐C3N4/CdS (4.84 mmol h−1 g−1). In addition, NiCoP‐g‐C3N4/CdS photocatalyst has excellent stability for hydrogen production. The materials were characterized and analyzed by XRD, SEM, TEM, XPS, UV‐Vis DRS, FTIR, UPS, N2 adsorption‐desorption process and electrochemical test etc. At the same time, the possible mechanism of NiCoP‐g‐C3N4/CdS photocatalytic hydrogen production reaction is proposed. This study provides a new idea for the rational design of heterojunction photocatalyst and transition metal phosphide cocatalyst. [ABSTRACT FROM AUTHOR]

Hydrogen is one of the most promising sustainable energy carriers for its high gravimetric energy density and abundance. Nowadays, hydrogen production and storage are the main constraints for its commercialization. As a current research focus, hydrogen production from methanol‐water reforming, especially at low temperature, is particularly important. In this study, a novel reaction path for low‐temperature methanol reforming through synergistic catalysis was developed. Alcohol dehydrogenase (ADH) and coenzyme I (nicotinamide adenine dinucleotide, NAD+) were employed for methanol catalytic dehydrogenation at low temperature, which could generate formaldehyde and reductive coenzyme I (NADH). Covalent triazine framework‐immobilized ruthenium complex (Ru‐CTF) was prepared afterwards. On one hand, the catalyst exhibited high activity for the formaldehyde–water shift reaction to generate hydrogen and carbon dioxide. On the other hand, the NADH dehydrogenation was also catalyzed by the Ru‐CTF, producing NAD+ and hydrogen. Additionally, the catalyst also showed high biocompatibility with ADH. Through the synergistic effect of the above two main processes, methanol could be converted into hydrogen and carbon dioxide stably at low temperature for more than 96 h. The hydrogen production rate was dependent on the pH of the reaction solution as well as the ADH dosage. A hydrogen production rate of 157 mmol h−1 mol−1Ru was achieved at the optimum pH (8.1). Additionally, the hydrogen production rate increased linearly with the ADH dosage, reaching 578 mmol h−1 mol−1Ru when the ADH dosage was 180 U at 35 °C. This research could not only help overcome the difficulties for methanol reforming near room temperature but also give new inspiration for designing new reaction pathways for methanol reforming. [ABSTRACT FROM AUTHOR]

Booming of photocatalytic water splitting technology (PWST) opens a new avenue for the sustainable synthesis of high‐value‐added hydrogenated and oxidized fine chemicals, in which the design of efficient semiconductors for the in‐situ and synergistic utilization of photogenerated redox centers are key roles. Herein, a porous polymeric carbon nitride (PPCN) with a crystalline backbone was constructed for visible light‐induced photocatalytic hydrogen generation by photoexcited electrons, followed by in‐situ utilization for olefin hydrogenation. Simultaneously, various alcohols were selectively transformed to valuable aldehydes or ketones by photoexcited holes. The porosity of PPCN provided it with a large surface area and a short transfer path for photogenerated carriers from the bulk to the surface, and the crystalline structure facilitated photogenerated charge transfer and separation, thus enhancing the overall photocatalytic performance. High reactivity and selectivity, good functionality tolerance, and broad reaction scope were achieved by this concerted photocatalysis system. The results contribute to the development of highly efficient semiconductor photocatalysts and synergistic redox reaction systems based on PWST for high‐value‐added fine chemical production. [ABSTRACT FROM AUTHOR]

The rapidly growing global need for environmentally friendly energy solutions has inspired extensive research and development efforts aimed at harnessing the potential of hydrogen energy. Hydrogen, with its diverse applications and relatively straightforward acquisition, is viewed as a promising energy carrier capable of tackling pressing issues, such as carbon emissions reduction and energy storage. This study conducts a preliminary investigation into effective hydrogen generation and storage systems, encompassing methods like water electrolysis, biomass reforming, and solar‐driven processes. Specifically, the study focuses on assessing the potential of nanostructured catalysts and innovative materials to enhance the productivity and versatility of hydrogen energy systems. Additionally, the utilization of novel materials not only improves hydrogen storage capacity and safety but also opens up possibilities for inventive applications, including on‐demand release and efficient transportation. Furthermore, critical factors such as catalyst design, material engineering, system integration, and technoeconomic viability are examined to identify challenges and chart paths for future advancements. The research emphasizes the importance of fostering interdisciplinary collaborations to advance hydrogen energy technologies and contribute to a sustainable energy future. [ABSTRACT FROM AUTHOR]

Hydrogen has garnered considerable attention as an environmentally friendly due to its sustainability and exceptional energy density, surpassing other chemical fuels. For H2 production, electrochemical water splitting is an economically viable and eco‐friendly method. Developing well‐organized electrocatalysts for electrochemical water splitting is pivotal in enabling long‐term hydrogen production, the critical component in the transition toward a cleaner and more environmentally sustainable energy landscape. During the last decades, to aid in oxygen evolution and hydrogen evolution reactions, numerous tungsten carbide‐based electrocatalysts have been established. WC developed as a promising candidate for electrolytic hydrogen generation. This review first explores the historical background and fundamental mechanisms underlying water splitting and subsequently investigates the field of WC‐based electrocatalysts. Furthermore, in both HER and OER, the thorough analysis examines the electrocatalytic performance of electrocatalysts based on WC. Finally, it discusses the challenges and prospects of developing WC‐based electrocatalysts for OER and HER, shedding light on their potential contributions to the sustainable energy landscape. [ABSTRACT FROM AUTHOR]

This research entails the simulation and thermodynamic evaluation of a combined solar‐powered system that is intended to achieve the energy necessary to construct factories in areas where other sources of energy are not available. The system comprises five major circuits: (1) a parabolic trough that collects solar energy and passes it to downstream circuits via an evaporator, (2) an organic Rankine cycle that generates electricity for devices and factories, (3) a proton exchange membrane electrolysis unit that produces hydrogen from pure water, (4) a methanation unit that produces gas by combining hydrogen and carbon dioxide, and (5) a reverse osmosis (RO) unit that purges seawater to produce freshwater. This investigation studies the efficiency of energy and exergy, the destruction rate of exergy, and the economic value of system components as a whole. The system is represented by the technical equation solver, and the results are obtained as a result. This research employs the genetic algorithm and Technique for Order of Preference by Similarity to Ideal Solution method to locate the most effective point. The achieved outcomes include a maximum total system efficiency of 54.935% and a minimum total cost of 2.578 $/GJ. Dated to the optimal point, the power generated is 305.5 kW, the required power of a single‐cell electrolyzer is 293.8 W, the mass flow rate of methane and hydrogen production is 448.92 kg/hr ${kg}/{hr}$ and 225.64 kg/h, respectively. The water volume generated by RO is 35.25 m3/h, and the total cost of the investment is 85.57 $/h. [ABSTRACT FROM AUTHOR]

The construction of the heterostructures with intimate contacts and prominent sunlight absorption capacity are essential for achieving the highly effective photocatalytic H2 evolution. Here, the CdS/MoS2 heterostructures constituted by CdS nanoparticals loaded on uniform MoS2 nanoribbons were synthesized through solid‐gas reaction and hydrothermal treatments. In the as‐prepared CdS/MoS2 heterostructures, there are large‐area contact interfaces between the external highly dispersed small CdS nanoparticals and MoS2 nanoribbons. Impressively, the optimized CdS/MoS2‐8 photocatalyst delivered the highest hydrogen production rate of 91.2 μmol h−1, which is 9 times that of CdS. It demonstrates that the formation of the heterostructures could effectively promote the separation and transfer of photogenerated charge carriers due to the intimate contacts between CdS nanoparticals and MoS2 nanoribbons. This work would provide a new method to develop efficient photocatalysts for photocatalytic H2 evolution. [ABSTRACT FROM AUTHOR]

Electrocatalytic water splitting to produce hydrogen and oxygen is regarded as one of the most promising methods to generate clean and sustainable energy for replacing fossil fuels. However, the design and development of an efficient bifunctional catalyst for simultaneous generation of hydrogen and oxygen remains extremely challenging yet is critical for the practical implementation of water electrolysis. Here, we report a facile method to fabricate novel N‐doped carbon nanotube frameworks (NCNTFs) by the pyrolysis of a bimetallic metal organic framework (MIL‐88‐Fe/Co). The resultant electrocatalyst, Co3Fe7@NCNTFs, exhibits excellent oxygen evolution reaction (OER) activity, achieving 10 mA/cm2 at a low overpotential of just 264 mV in 1 M KOH solution, and 197 mV for the hydrogen evolution reaction. The high electrocatalytic activity arises from the synergistic effect between the chemistry of the Co3Fe7 and the NCNTs coupled to the novel framework structure. The remarkable electrocatalytic performance of our bifunctional electrocatalyst provides a promising pathway to high‐performance overall water splitting and electrochemical energy devices. [ABSTRACT FROM AUTHOR]

Electrochemical hydrogen generation is a rising prospect for future renewable energy storage and conversion. Platinum remains a leading choice of catalyst, but because of its high cost and low natural abundance, it is critical to optimize its use. In the present study, platinum oxide nanoparticles of approximately 2 nm in diameter are deposited on carbon nitride (C3N4) nanosheets by thermal refluxing of C3N4 and PtCl2 or PtCl4 in water. These nanoparticles exhibit apparent electrocatalytic activity toward the hydrogen evolution reaction (HER) in acid. Interestingly, the HER activity increases with increasing Pt4+ concentration in the nanoparticles, and the optimized catalyst even outperforms commercial Pt/C, exhibiting an overpotential of only -7.7 mV to reach the current density of 10 mAcm-2 and a Tafel slope of -26.3 mVdec-1. The results from this study suggest that the future design of platinum oxide catalysts should strive to maximize the Pt4+ sites and minimize the formation of the less active Pt2+ species. [ABSTRACT FROM AUTHOR]

The realization of large‐scale industrial application of alkaline water electrolysis for hydrogen generation is severely hampered by the cost of electricity. Therefore, it is currently necessary to synthesize highly efficient electrocatalysts with excellent stability and low overpotential under an industrial‐level current density. Herein, Ir‐incorporated in partially oxidized Ru aerogel has been designed and synthesized via a simple in situ reduction strategy and subsequent oxidation process. The electrochemical measurements demonstrate that the optimized Ru98Ir2‐350 electrocatalyst exhibits outstanding hydrogen evolution reaction (HER) performance in an alkaline environment (1 M KOH). Especially, at the large current density of 1000 mA cm−2, the overpotential is as low as 121 mV, far exceeding the benchmark Pt/C catalyst. Moreover, the Ru98Ir2‐350 catalyst also displays excellent stability over 1500 h at 1000 mA cm−2, denoting its industrial applicability. This work provides an efficient route for developing highly active and ultra‐stable electrocatalysts for hydrogen generation under industrial‐level current density. [ABSTRACT FROM AUTHOR]

Producing hydrogen from water in an efficient way could significantly reduce consumption of fossil fuels. The abundance of water in oceans offers a large‐scale alternative approach for water splitting using seawater. The direct use of seawater for the generation of hydrogen is a difficult and complex process due to the presence of various ions in seawater, which affect the activity of the catalysts and makes the selectivity towards efficient water splitting a challenging task. In their Full Paper on page 18455 ff., C. N. R. Rao et al. report on various ways to efficiently reduce seawater to hydrogen under visible‐light irradiation by various catalysts. [ABSTRACT FROM AUTHOR]

Due to the pressing environmental problems coming from the transport sector, interest in electric vehicles (EVs) has increased significantly over the last decade. Although different types of EVs are available on the market, the largest contribution to the reduction of environmental problems could be made through zero‐emission vehicles, such as battery electric vehicles (BEVs) and fuel cell vehicles (FCVs). Each of these vehicles has some advantages and disadvantages. The problem they share is the high purchase price in comparison to conventional gasoline vehicles. Through the improvement of battery performance, further technological learning and a mix of different direct and indirect supporting policy measures, the competiveness of EVs could be significantly improved. EVs could already contribute to the reduction of emissions today, however the full environmental benefit of BEVs and FCVs is related to the mix of the primary energy sources used for electricity generation and hydrogen production. The increasing use of renewable energy sources in electricity generation makes EVs more environmentally friendly. Since total emissions are also dependent on the embedded emissions of cars, their lifetime as well as their usage (specific vehicle kilometers driven per year) have significant impacts on the total emissions per km driven. [ABSTRACT FROM AUTHOR]

LINKED CONTENT This article is linked to Ianiro et al paper. To view this article, visit https://doi.org/10.1111/apt.14201. [ABSTRACT FROM AUTHOR]

It is an effective strategy to construct a photogenerated carrier‐transfer channel based on the load between photocatalysts to improve the light‐absorption capacity and separation efficiency of a single photocatalyst. In this work, the MoP is embedded on the surface of ZnIn2S4 through electrostatic self‐assembly to form ZnIn2S4/MoP‐20%, the hydrogen production performance is 151.93 μmol in 5 h, and is 13 times that of ZnIn2S4, which greatly improves the hydrogen production performance of ZnIn2S4. Based on density functional theory (DFT) calculation, MoP with metallike properties and semiconductor ZnIn2S4 with indirect bandgap successfully constructed Schottky junction. MoP acts as the active site in hydrogen production system and accepts photogenerated electrons through Schottky junction, which can effectively accelerate the separation of electron–hole pairs and enable more effective photogenerated electrons to participate in photocatalytic hydrogen production reaction. In this experiment, a new method is provided for the development of Schottky junction based on DFT calculation to efficiently use solar photocatalytic water to produce hydrogen. [ABSTRACT FROM AUTHOR]

Europa's long‐term habitability depends on thermodynamics—modulated by tidal evolution—and geochemical pathways that define chemical and energy inventories for use by putative biology. Hydrogen produced from the reaction of water and rock during serpentinization is one potential source of metabolic energy. Here, we demonstrate how thermally modulated volumetric changes to Europa's ice shell, ocean, and fluid‐accessible rocky mantle influence oceanic salinity and serpentinization rates in Europa's interior. During periods of steady cooling, hydrogen flux into the ocean remains relatively constant because of the continuous propagation of thermal cracking into the rocky mantle regardless of ocean composition. However, during periods of fluctuating heat production driven by changes in orbital eccentricity, modulation of the ice shell volume, and consequently the salinity and water activity of the ocean, alters the serpentinization rate. In parallel, the extent of fracturing within the seafloor varies, changing the volume of reactable rock available. Our results show that the stability of serpentinization reactions on Europa over time highly depends on the thermal‐orbital evolution and oceanic salt content. The variability in the hydrogen production rate is significant across potential orbital histories, varying by up to 15 orders of magnitude for the lowest salinity and most kosmotropic ocean conditions, such as dilute MgSO4 compositions. We also show that this variability decreases with increasing ocean salinity and more chaotropic compositions, such as a concentrated NaCl ocean. These results suggest new ways that ocean composition and water activity are essential to stable habitable conditions in ocean worlds. Plain Language Summary: Europa, a satellite of Jupiter, is believed to harbor a liquid water ocean beneath its frozen surface, which has significance for investigations of habitability within our Solar System. This ocean is likely maintained partially by tidal heating in tandem with the evolution of its orbit, potentially leading to heat fluctuations within the satellite over time. Such thermal fluctuations may have resulted in oscillations in other systems within Europa, including ocean composition. We examine thermally driven volume changes in the ice and ocean of Europa. This allows us to model changes in ocean salinity, which can affect reaction rates at the seafloor, including the reaction of olivine and water into silica and hydrogen, called serpentinization. We model the amount of olivine available for serpentinization through changes in fractured seafloor volume and track the relative amounts of previously reacted material within the seafloor. We find that hydrogen production is variable according to the satellite's thermal history and shifts in ocean salinity. Since hydrogen can be an energy source for life, these parallel changes in hydrogen production and oceanic salinity may affect energy availability for any life that may be or have been inside Europa. Key Points: Changes in Europa's thermal state shift ocean salinity, affecting the hydrogen flux from seafloor reactionsEuropa may have undergone cyclic hydrogen flux if heat production fluctuated in the satellite's pastHydrogen flux is potentially more consistent over time if chaotropic salts, such as sodium chloride, dominate Europa's ocean [ABSTRACT FROM AUTHOR]

Multicomponent metallacages can integrate the functions of their different building blocks to achieve synergetic effects for advanced applications. Herein, based on metal‐coordination‐driven self‐assembly, we report the preparation of a series of isoreticular tetraphenylethylene‐based metallacages, which are well characterized by multinuclear NMR, ESI‐TOF‐MS and single‐crystal X‐ray diffraction techniques. The suitable integration of photosensitizing tetraphenylethylene units as faces and Re catalytic complexes as the pillars into a single metallacage offers a high photocatalytic hydrogen production rate of 1707 μmol g−1 h−1, which is one of the highest values among reported metallacages. Femtosecond transient absorption and DFT calculations reveal that the metallacage can serve as a platform for the precise and organized arrangement of the two building blocks, enabling efficient and directional electron transfer for highly efficient photocatalytic performance. This study provides a general strategy to integrate multifunctional ligands into a certain metallacage to improve the efficiency of photocatalytic hydrogen production, which will guide the future design of metallacages towards photocatalysis. [ABSTRACT FROM AUTHOR]

BACKGROUND: The increase in energy and water demand due to industrialization and urbanization requires prioritized solutions for a sustainable future. Microbial electrolysis cells (MECs) have shown huge potential for biohydrogen production along with wastewater treatment. This study examined the effectiveness of employing nickel foam as an anode material for biohydrogen production from the widely available potato industry effluent. RESULTS: Hydrogen production rate increases exponentially with the increase in applied voltage. A maximum hydrogen production rate of 0.69 ± 0.02 m3 H2 m−3 reactor volume d−1 was achieved at 0.9 V with a maximum chemical oxygen demand removal efficiency of 97% at 0.8 V. The effluent of the 0.8 V cycle had the least salinity, low total dissolved solids, 84% reduced total hardness, highest effluent clarity (4.30 NTU, and negligible quantity of heavy metals. CONCLUSION: This study successfully produced biohydrogen from potato wastewater within 5 days of operation along with wastewater treatment of the substrate. The improved performance of the system can be attributed to the unique characteristics of nickel foam, such as high porosity, large surface area and excellent conductivity. The findings of this study have implications for the sustainable treatment of domestic and agro‐industrial wastewater and the development of efficient and low‐cost bio‐electrochemical systems for renewable energy production. © 2023 Society of Chemical Industry (SCI). [ABSTRACT FROM AUTHOR]

The lack of highly efficient photoanodes presents a significant challenge to implementing the promising strategy of unbiased solar‐to‐fuel conversion. To achieve high‐performance photoanodes, improving their light harvesting and charge separation/injection capabilities is indispensable. Herein, solution‐processed vertically oriented Sb2S3 nanorod arrays on substrate are obtained via a Au seed layer, resulting in improved optoelectronic properties (due to the light scattering effect) and favorable crystallographic orientation of the 1D nanostructure. Moreover, the (NH4)2WS4 treatment caps the surface of the nanorods with an amorphous WSx layer and passivates the sulfur vacancy of Sb2S3, resulting in boosted charge extraction to the reactants. The resulting photoanode is employed to drive an iodide oxidation reaction (IOR), which is a prominent alternative to sluggish water oxidation reactions, exhibiting a high photocurrent density of 13 mA cm−2 at 0.6 V versus the reversible hydrogen electrode. Subsequently, an unassisted hydrogen generation device is demonstrated by combining an Sb2S3 nanorod array‐based photoanode for IOR and a perovskite‐based photocathode for the hydrogen evolution reaction, achieving an efficient hydrogen production current density of 5.7 mA cm−2 without any external bias. [ABSTRACT FROM AUTHOR]