Search Results (557)

The high cost of hydrogen production is the primary factor limiting the development of the hydrogen energy industry chain. Additionally, due to the inefficiency of hydrogen production by water electrolysis technology, the development of high-performance catalysts is an effective means of producing low-cost hydrogen. In water electrolysis technology, the electrocatalytic activity of the electrode affects the kinetics of the oxygen evolution reaction (OER) and the hydrogen evolution rate. This study utilizes the liquid phase co-precipitation method to synthesize three types of Prussian blue analog (PBA) electrocatalytic materials: Fe/PBA(Fe₄[Fe(CN)₆]₃), Fe-Mn/PBA((Fe, Mn)₃[Fe(CN)₆]₂·nH₂O), and Fe-Mn-Co/PBA((Mn, Co, Fe)₃^II[Fe^III(CN)₆]₂·nH₂O). X-ray diffraction (XRD) and scanning electron microscopy (SEM) analyses show that Fe-Mn-Co/PBA has a smaller particle size and higher crystallinity, and its grain boundary defects provide more active sites for electrochemical reactions. The electrochemical test shows that Fe-Mn-Co/PBA exhibits the best electrochemical performance. The overpotential of the oxygen evolution reaction (OER) under 1 M alkaline electrolyte at 10/50 mA·cm⁻² is 270/350 mV, with a Tafel slope of 48 mV·dec⁻¹, and stable electrocatalytic activity is maintained at 5 mA·cm⁻². All of these are attributed to the synergistic effect of Fe, Mn, and Co metal ions, grain refinement, and the generation of grain boundary defects and internal stresses. Full article

In recent years, Ga-based liquid metals have emerged as a prominent research focus in catalysis, owing to their unique properties, including fluidity, low melting point, high thermal and electrical conductivity, and tunable surface characteristics. This review summarizes the synthesis strategies for Ga-based liquid metal catalysts, with a focus on recent advances in their applications across electrocatalysis, thermal catalysis, photocatalysis, and related fields. In electrocatalysis, these catalysts exhibit potential for reactions such as electrocatalytic CO₂ reduction, electrocatalytic ammonia synthesis, electrocatalytic hydrogen production, and the electrocatalytic oxidation of alcohols. As to thermal catalysis, these catalysts are employed in processes such as alkane dehydrogenation, selective hydrogenation, thermocatalytic CO₂ reduction, thermocatalytic ammonia synthesis, and thermocatalytic plastic degradation. In photocatalysis, they can be used in other photocatalytic reactions such as organic matter degradation and overall water splitting. Furthermore, Ga-based liquid metal catalysts also exhibit distinct advantages in catalytic reactions within battery systems and mechano-driven catalysis, offering innovative concepts and technical pathways for developing novel catalytic systems. Finally, this review discusses the current challenges and future prospects in Ga-based liquid metal catalysis. Full article

Electrochemical water splitting represents a sustainable approach for hydrogen production, yet efficient hydrogen evolution reaction (HER) catalysts operating in alkaline environments remain critically needed. Herein, we report the fabrication of Co₃O₄–NiS₂ nanocomposites synthesized through a facile coprecipitation and subsequent thermal treatment method. Detailed characterization via physicochemical techniques confirmed the successful formation of a hybrid Co₃O₄–NiS₂ heterostructure with tunable compositional and morphological characteristics. Among the synthesized catalysts (Co–Ni–1, Co–Ni–2, and Co–Ni–3), the Co–Ni–2 sample demonstrated optimal structural integration, displaying interconnected nanosheet morphologies and balanced elemental distribution. Remarkably, Co–Ni–2 achieved exceptional HER performance in 1 M KOH electrolyte, requiring an ultralow overpotential of only 84 mV at 10 mA cm⁻² and exhibiting a favorable Tafel slope of 67.5 mV dec⁻¹. Electrochemical impedance spectroscopy and electrochemical surface area measurements further substantiated the superior electrocatalytic kinetics, rapid charge transport, and abundant active site accessibility in the optimized Co–Ni–2 composite. Additionally, Co–Ni–2 demonstrated outstanding durability with negligible activity decay over 5000 cycles. This study not only highlights the strategic synthesis of Co₃O₄–NiS₂ nanostructures but also provides valuable insights for designing advanced, stable, and efficient non-noble electrocatalysts for sustainable hydrogen generation. Full article

To address the low selectivity in the electrocatalytic conversion of furfural (FFR) to furfuryl alcohol (FFA) under alkaline conditions, a Zn-based metal–organic framework (MBON-2) featuring a 3D hierarchical flower-like architecture self-assembled from nanosheets was synthesized via a simple hydrothermal method. Under optimal conditions, MBON-2 exhibited an extremely high selectivity of FFA (100%) and a high Faradaic efficiency (FE) of 93.19% at −0.2 V vs. RHE. Electrochemical impedance spectroscopy (EIS) revealed the excellent electron transfer and mass transport properties of MBON-2. In addition, in situ Fourier transform infrared (FTIR) spectroscopy studies confirmed the adsorption of FFR molecules onto the Zn and B sites of MBON-2 during the ECH of FFR, providing key insights into the hydrogenation mechanism. The numerous exposed B and Zn sites of the MBON-2, as well as its robust structural stability contributed to its outstanding catalytic performance in the electrochemical hydrogenation (ECH) of FFR. This work provides valuable guidelines for developing efficient Zn-based catalysts for the ECH of FFR. Full article

Hydrogen, as a renewable and clean energy with a high energy density, is of great significance to the realization of carbon neutrality. In recent years, extensive research has been conducted on the electrocatalytic hydrogen evolution reaction (HER) by splitting water, with a focus on developing efficient electrocatalysts that can perform the HER at an overpotential with minimal power consumption. Tungsten oxide (WO₃), a non-noble-metal-based material, has great potential in hydrogen evolution due to its excellent redox capability, low cost, and high stability. However, it cannot meet practical needs because of its poor electrical conductivity and the limited number of active sites; thus, it is necessary to further improve HER performance. In this review, recent advances related to WO3-based electrocatalysts for the HER are introduced. Most importantly, several tactics for optimizing the electrocatalytic HER activity of WO₃ are summarized, such as controlling its morphology, phase transition, defect engineering (anion vacancies, cation doping, and interstitial atoms), constructing a heterostructure, and the microenvironment effect. This review can provide insight into the development of novel catalysts with high activity for the HER and other renewable energy applications. Full article

The electrocatalytic CO₂ reduction reaction (CO₂RR) offers an energy-saving and environmentally friendly approach to producing hydrocarbon fuels. The use of a gas diffusion electrode (GDE) flow cell has generally improved the rate of CO₂RR, while the gas diffusion layer (GDL) remains a significant challenge. In this study, we successfully engineered a novel metal–organic framework (MOF) heterojunction through the controlled coating of zeolitic imidazolate framework (ZIF-L) on ultrathin nickel—metal–organic framework (Ni-MOF) nanosheets. This innovative architecture simultaneously integrates GDL functionality and exposes abundant solid–liquid–gas triple-phase boundaries. The resulting Ni-MOF@ZIF-L heterostructure demonstrates exceptional performance, achieving a formate Faradaic efficiency of 92.4% while suppressing the hydrogen evolution reaction (HER) to 6.7%. Through computational modeling of the optimized heterojunction configuration, we further elucidated its competitive adsorption behavior and electronic modulation effects. The experimental and theoretical results demonstrate an improvement in electrochemical CO₂ reduction activity with suppressed hydrogen evolution for the heterojunction because of its hydrophobic interface, good electron transfer capability, and high CO₂ adsorption at the catalyst interface. This work provides a new insight into the rational design of porous crystalline materials in electrocatalytic CO₂RR. Full article

The electrocatalytic decomposition of ammonia represents a promising route for sustainable hydrogen production, yet current systems rely heavily on noble metal catalysts with prohibitive costs and limited durability. A critical challenge lies in developing non-noble electrocatalysts that simultaneously achieve high active site exposure, optimized electronic configurations, and robust structural stability. Addressing these requirements, this study strategically engineered Cu-doped ZIF-8 architectures via in situ growth on nickel foam (NF) substrates through a facile room-temperature hydrothermal synthesis approach. Systematic optimization of the Cu/Zn molar ratio revealed that Cu_0.7Zn_0.3-ZIF/NF achieved optimal performance, exhibiting a distinctive nanoflower-like architecture that substantially increased accessible active sites. The hybrid catalyst demonstrated superior electrocatalytic performance with a current density of 124 mA cm⁻² at 1.6 V vs. RHE and a notably low Tafel slope of 30.94 mV dec⁻¹, outperforming both Zn-ZIF/NF (39.45 mV dec⁻¹) and Cu-ZIF/NF (31.39 mV dec⁻¹). Combined XPS and EDS analyses unveiled a synergistic electronic structure modulation between Zn and Cu, which facilitated charge transfer and enhanced catalytic efficiency. A gas chromatography product analysis identified H₂ and N₂ as the primary gaseous products, confirming the predominant occurrence of the ammonia oxidation reaction (AOR). This study not only presents a noble metal-free electrocatalyst with exceptional efficiency and durability for ammonia decomposition but also demonstrates the significant potential of MOF-derived materials in sustainable hydrogen production technologies. Full article

Sulfion oxidation reaction (SOR) has great potential in replacing oxygen evolution reaction (OER) and boosting highly efficient hydrogen evolution. The development of highly active and stable SOR electrocatalysts is crucial for assisting hydrogen production with low energy consumption. In this work, multiphase NiCoFe-based layered double hydroxide (namely NiCoFe-LDH) has been synthesized via a facile seed-assisted heterogeneous nucleation method. Benefiting from its unique microsized hydrangea-like structure and synergistic active phases, the catalyst delivers substantial catalytic interfaces and reactive centers for SOR. Consequently, NiCoFe-LDH electrode achieves a remarkably low potential of 0.381 V at 10 mA cm⁻² in 1 M KOH + 0.1 M Na₂S, representing a significant reduction of 0.98 V compared to conventional OER. Notably, under harsh industrial conditions (6 M KOH + 0.1 M Na₂S, 80 °C), the electrolysis system based on NiCoFe-LDH||NF pair exhibits a cell potential of only 0.71 V at 100 mA cm⁻², which shows a greater decreasing amplitude of 1.05 V compared with that of traditional OER/HER systems. Meanwhile, the NiCoFe-LDH||NF couple could maintain operational stability for 100 h without obvious potential fluctuation, as well as possessing a lower energy consumption of 1.42 kWh m⁻³ H₂. Multiphase eletrocatalysis for SOR could indeed produce hydrogen with low-energy consumption. Full article

Ferrocene (Fc) is a redox-active organometallic scaffold whose unique electronic properties, stability, and modularity have enabled a broad range of catalytic and sensing applications. This review critically examines recent advances in Fc-based systems for hydrogen evolution and carbon dioxide (CO₂) conversion, encompassing electrochemical, photochemical, and thermochemical strategies. Fc serves diverse functions: it operates as a reversible redox mediator, an electron reservoir, a ligand framework, and a structural modulator. Each role contributes differently to enhancing catalytic performance, improving selectivity, or increasing operational stability. We highlight how Fc integration facilitates proton-coupled electron transfer in hydrogen evolution, supports selective CO₂ reduction in molecular and hybrid catalysts, and promotes efficient CO₂ fixation and capture within functionalised frameworks. Emerging applications in electrosynthetic organic transformations are also discussed. Together, these findings position Fc as a foundational motif for designing future electrocatalytic and carbon management platforms. Full article

The rapid growth in population and industrialization have significantly increased global energy demand, placing immense pressure on finite and environmentally harmful conventional fossil fuel-based energy sources. In this context, the development of hybrid electrocatalysts presents a crucial solution for energy conversion and storage, addressing environmental challenges while meeting rising energy needs. In this study, the fabrication of a novel bifunctional catalyst, copper nickel aluminum spinel (Cu_0.5Ni_0.5Al₂O₄) supported on graphitic carbon nitride (GCN), using a solid-state synthesis process is reported. Because of its effective interface design and spinel cubic structure, the Cu_0.5Ni_0.5Al₂O₄/GCN nanocomposite, as synthesized, performs exceptionally well in electrochemical energy conversion, such as the oxygen evolution reaction (OER), the hydrogen evolution reaction (HER), and energy storage. In particular, compared to noble metals, Pt/C- and IrO₂-based water-splitting cells require higher voltages (1.70 V), while for the Cu_0.5Ni_0.5Al₂O₄/GCN nanocomposite, a voltage of 1.49 V is sufficient to generate a current density of 10 mA cm⁻² in an alkaline solution. When used as supercapacitor electrode materials, Cu_0.5Ni_0.5Al₂O₄/GCN nanocomposites show a specific capacitance of 1290 F g⁻¹ at a current density of 1 A g⁻¹ and maintain a specific capacitance of 609 F g⁻¹ even at a higher current density of 5 A g⁻¹, suggesting exceptional rate performance and charge storage capacity. The electrode’s exceptional capacitive properties were further confirmed through the determination of the roughness factor (Rf), which represents surface heterogeneity and active area enhancement, with a value of 345.5. These distinctive characteristics render the Cu_0.5Ni_0.5Al₂O₄/GCN composite a compelling alternative to fossil fuels in the ongoing quest for a viable replacement. Undoubtedly, the creation of the Cu_0.5Ni_0.5Al₂O₄/GCN composite represents a significant breakthrough in addressing the energy crisis and environmental concerns. Owing to its unique composition and electrocatalytic characteristics, it is considered a feasible choice in the pursuit of ecologically sustainable alternatives to fossil fuels. Full article

Electro-oxidation of urea (UOR) in alkaline medium is one of the most effective alternative ways of producing green hydrogen, as the oxidation potential in UOR is less and thermodynamically more favorable than conventional water oxidation. The development of cost-effective materials in catalyzing UOR is recently seeking more attention in the research hotspot. Suitably modifying the Ni-based catalysts towards active site creation and preventing surface passivation is much important in this context, following which we reported the synthesis of Ni₃S₂ (NS) supported with CuCo (CC) bimetallic (NSCC). A simple hydrothermal route for NS synthesis and the electrodeposition method for CuCo (CC) deposition is adapted in a self-supported manner. The NS and CC catalysts exhibited sheet-like morphology, as confirmed by SEM and TEM analysis. The bimetallic CC deposition prevented the surface passivation of nickel sulfide (NS) over oxygen evolution reaction (OER) and improved the charge-transfer kinetics. The NSCC catalyst catalyzed UOR in an alkaline medium, which required a lower potential of 1.335 V vs. RHE to attain the current density of 10 mAcm⁻², with a lower Tafel slope value of 131 mVdec⁻¹. In addition, a two-electrode cell setup is constructed with an operating cell voltage of 1.512 V for delivering 10 mAcm⁻² current density. This study illustrates the new strategy of designing heterostructure catalysts for electrocatalytic UOR. Full article

Electrocatalytic urea oxidation reaction (UOR) is a promising dual-purpose approach for hydrogen production and wastewater treatment, addressing critical energy and environmental challenges. However, conventional anode materials often suffer from limited active sites and high charge transfer resistance, restricting UOR efficiency. To overcome these issues, a novel NiP@PNC/NF electrocatalyst was developed via a one-step thermal annealing process under nitrogen, integrating nickel phosphide (NiP) with phosphorus and nitrogen co-doped carbon nanotubes (PNCs) on a nickel foam (NF) substrate. This design enhances catalytic activity and charge transfer, achieving current densities of 50 mA cm⁻² at 1.34 V and 100 mA cm⁻² at 1.43 V versus the reversible hydrogen electrode (RHE). The electrode’s high electrochemical surface area (235 cm²) and double-layer capacitance (94.1 mF) reflect abundant active sites, far surpassing NiP/NF (48 cm², 15.8 mF) and PNC/NF (39.5 cm², 12.9 mF). It maintains exceptional stability, with only a 16.3% performance loss after 35 h, as confirmed by HR-TEM showing an intact nanostructure. Our single-step annealing technique provides simplicity, scalability, and efficient integration of NiP nanoparticles inside a PNC matrix on nickel foam. This method enables consistent distribution and robust substrate adhesion, which are difficult to attain with multi-step or more intricate techniques. Full article

The simultaneous generation of hydrogen fuel and wastewater remediation via electrocatalytic urea oxidation has emerged as a promising approach for sustainable energy and environmental solutions. However, the practical application of this process is hindered by the limited active sites and high charge-transfer resistance of conventional anode materials. In this work, we introduce a novel CoP@P, N-CNTs/NF electrocatalyst, fabricated through a facile one-step thermal annealing technique. Comprehensive characterizations confirm the successful integration of CoP nanoparticles and phosphorus/nitrogen co-doped carbon nanotubes (P, N-CNTs) onto nickel foam, yielding a unique hierarchical structure that offers abundant active sites and accelerated electron transport. As a result, the CoP@P, N-CNTs/NF electrode achieves outstanding urea oxidation reaction (UOR) performance, delivering current densities of 158.5 mA cm⁻² at 1.5 V and 232.95 mA cm⁻² at 1.6 V versus RHE, along with exceptional operational stability exceeding 50 h with negligible performance loss. This innovative, multi-element-doped electrode design marks a significant advancement in the field, enabling highly efficient UOR and energy-efficient hydrogen production. Our approach paves the way for scalable, cost-effective solutions that couple renewable energy generation with effective wastewater treatment. Full article

Single-atom catalysts characterized by their novel electronic configurations and exceptional atomic utilization efficiency have emerged as potential alternatives to costly noble metal catalysts, garnering extensive research attention in various electrocatalytic fields. However, the inherent characteristics of single metal centers constrain their further application in catalyzing multi-electron reactions. In contrast, multi-atom catalysts (MACs), particularly dual-atom catalysts (DACs), possess multiple active metal sites that can significantly enhance catalytic performance through synergistic effects. This review summarizes recent developments in multi-atom catalysts, focusing on synthesis methods, design strategies, and the correlation between interatomic synergy and catalytic efficiency. Furthermore, we discuss their applications in key electrochemical reactions, including the hydrogen evolution reaction, oxygen reduction reaction, and oxygen evolution reaction. Finally, we outline the opportunities and challenges in this field to guide the development of high-efficiency catalysts for sustainable energy conversion applications. Full article

Titanium dioxide (TiO₂) is a wide-bandgap semiconductor material with broad application potential, known for its excellent photocatalytic performance, high chemical stability, low cost, and non-toxicity. These properties make it highly attractive for applications in photovoltaic energy, environmental remediation, and optoelectronic devices. For instance, TiO₂ is widely used as a photocatalyst for hydrogen production via water splitting and for degrading organic pollutants, thanks to its efficient photo-generated electron–hole separation. Additionally, TiO₂ exhibits remarkable performance in dye-sensitized solar cells and photodetectors, providing critical support for advancements in green energy and photoelectric conversion technologies. Boron-doped diamond (BDD) is renowned for its exceptional electrical conductivity, high hardness, wide electrochemical window, and outstanding chemical inertness. These unique characteristics enable its extensive use in fields such as electrochemical analysis, electrocatalysis, sensors, and biomedicine. For example, BDD electrodes exhibit high sensitivity and stability in detecting trace chemicals and pollutants, while also demonstrating excellent performance in electrocatalytic water splitting and industrial wastewater treatment. Its chemical stability and biocompatibility make it an ideal material for biosensors and implantable devices. Research indicates that the combination of TiO₂ nanostructures and BDD into heterostructures can exhibit unexpected optical and electrical performance and transport behavior, opening up new possibilities for photoluminescence and rectifier diode devices. However, applications based on this heterostructure still face challenges, particularly in terms of photodetector, photoelectric emitter, optical modulator, and optical fiber devices under high-temperature conditions. This article explores the potential and prospects of their combined heterostructures in the field of optoelectronic devices such as photodetector, light emitting diode (LED), memory, field effect transistor (FET) and sensing. TiO₂/BDD heterojunction can enhance photoresponsivity and extend the spectral detection range which enables stability in high-temperature and harsh environments due to BDD’s thermal conductivity. This article proposes future research directions and prospects to facilitate the development of TiO₂ nanostructured materials and BDD-based heterostructures, providing a foundation for enhancing photoresponsivity and extending the spectral detection range enables stability in high-temperature and high-frequency optoelectronic devices field. Further research and exploration of optoelectronic devices based on TiO₂-BDD heterostructures hold significant importance, offering new breakthroughs and innovations for the future development of optoelectronic technology. Full article