Electrochemical water splitting is an efficient and eco-friendly method for hydrogen production, offering a sustainable energy solution. Currently, the noble metal platinum is considered to be the most efficient catalyst for electrochemical hydrogen evolution reactions (HERs). Due to the scarcity and high cost of noble metal materials, there is an urgent need to find abundant and cost-effective non-noble metal catalysts to reduce the overpotential of HERs. In recent years, significant scientific advancements have been reported in non-noble metal HER catalysts. This review categorizes and reviews the recent non-noble metal HER catalysts and their reaction mechanisms. An exhaustive overview of proven effective catalyst categories is provided, offering early-career researchers a panoramic understanding of this dynamic research field. Finally, we address current challenges and future directions in this field to encourage further research efforts and the development of non-noble metal catalysts.

Rapid industrial growth has overexploited fossil fuels, making hydrogen energy a crucial research area for its high energy and zero carbon emissions. Water electrolysis is a promising method as it is greenhouse gas-free and energy-efficient. However, OER, a slow multi-electron transfer process, is the limiting step. Thus, developing efficient, low-cost, abundant electrocatalysts is vital for large-scale water electrolysis. In this paper, the application and progress of transition metal chalcogenides (TMCs) as catalysts for the oxygen evolution reaction in recent years are comprehensively reviewed. The key findings highlight the catalytic mechanism and performance of TMCs synthesized using single or multiple transition metals. Notably, modifications through recombination, heterogeneous interface engineering, vacancy, and atom doping are found to effectively regulate the electronic structure of metal chalcogenides, increasing the number of active centers and reducing the adsorption energy of reaction intermediates and energy barriers in OER. The paper further discusses the shortcomings and challenges of TMCs as OER catalysts, including low electrical conductivity, limited active sites, and insufficient stability under harsh conditions. Finally, potential research directions for developing new TMC catalysts with enhanced efficiency and stability are proposed.

In the water splitting process for sustainable hydrogen production, the oxygen evolution reaction (OER) stands as one of the pivotal half-reactions. Nevertheless, the sluggish four-electron transfer process inherent to OER has emerged as a kinetic bottleneck that impedes water electrolysis. To address this challenge, researchers have been devoting substantial efforts to developing high-performance OER electrocatalysts. Currently, iridium (Ir)-based or ruthenium (Ru)-based oxides are widely acknowledged as benchmark catalysts for OER. However, their scarcity and exorbitant cost render large-scale applications impractical. In recent years, transition metal carbides have garnered extensive attention in the realm of OER electrocatalysts, exhibiting tremendous application prospects owing to their advantages of low cost, high catalytic activity, and excellent stability. This review briefly introduces the fundamental characteristics and synthesis methodologies of transition metal carbides, summarizes the recent research advances in their application as OER catalysts, elaborates on the modification strategies and catalytic mechanisms of transition metal carbide nanomaterials, and finally discusses the challenges confronted by these metal carbides as well as the future research directions.

The electrochemical reduction of carbon dioxide (CO₂RR) utilizing intermittent electricity from renewable energy sources represents an emerging and promising approach to achieve carbon neutrality and mitigate the greenhouse effect. This review comprehensively summarizes recent advances in Cu-based metal–organic framework (MOF) electrocatalysts for CO₂RR, focusing on their applications in producing C₁ and C₂₊ products. This paper highlights key strategies such as nanostructure manipulation, multi-component tandem catalysis, single-atom alloying, and ligand functionalization to optimize the binding energies of intermediate species and promote selective CO₂RR pathways. Numerous examples are presented, showcasing remarkable Faradaic efficiencies and product selectivities achieved through rational catalyst design. Furthermore, the use of MOF-derived materials and composites with other materials, like carbon nanotubes, graphene, and metal oxides, is discussed to enhance conductivity, stability, and selectivity. Despite the significant progress, challenges remain in achieving stable and scalable catalysts with high activity and selectivity towards specific C₂₊ products. This review underscores the importance of precise control of catalyst composition, structure, and surface properties to tackle these challenges and provides valuable insights for future research directions in developing advanced Cu-based MOF electrocatalysts for practical applications in CO₂ conversion technologies.

Hydrogen production by the electrolysis of water has become an important way to prepare green hydrogen because of its simple process and high product purity. However, the oxygen evolution reaction (OER) in the electrolysis process has a high overpotential, which leads to the increase of energy consumption. Developing efficient, stable and low-cost electrolytic water catalyst is the core challenge to reduce the reaction energy barrier and improve the energy conversion efficiency. CoS@NiS-80% nanosheets with rich heterogeneous interfaces were successfully synthesized by hydrothermal reaction and sulfuration. Heterogeneous interface not only promotes the effective charge transfer between different materials and reduces the charge transfer resistance but also accelerates the four-electron transfer process through the synergistic effect of nickel and cobalt atoms. Under alkaline conditions, the overpotential of CoS@NiS-80% nanosheets was only 280 mV at a current density of 10 mA cm⁻², with a Tafel slope of 100.87 mV dec⁻¹. Furthermore, it could work continuously for 100 h, exhibiting its outstanding stability. This work provides a novel approach for improving the OER performance of transition metal sulfide-based electrocatalysts through heterogeneous interface engineering.