Advancements in carbon-based transition metal compounds for enhanced hydrogen production via electrochemical water splitting☆

The hunt for sustainable energy sources has been driven by the depletion of nonrenewable fossil fuels, with hydrogen gas emerging as a promising substitute. Recently, there has been considerable interest in the hydrogen evolution reaction (HER) involving carbon-based molecules and transition metals. Viable alternatives to platinum-based electrocatalysts, such as carbon-based transition metal nitrides, carbides, and phosphides, have demonstrated remarkable activity and effectiveness in promoting HER under various conditions. The discovery of carbon-based transition metal and two-dimensional (2D) heterostructure electrocatalysts with low overpotentials has sparked considerable interest. Introducing transition metal nanoparticles into nonmetal materials increases the active surface area for the HER and enhances the catalytic performance. This article evaluates the effectiveness of these electrocatalysts in the HER process using carbon-based transition metal compounds, covering their performance over recent years. The article also emphasizes notable advancements in the research and production of carbon-based transition metal compounds, which have proven to be highly efficient catalysts for HER. This includes the use of earth-abundant substances and the design of 2D heterostructure electrocatalysts. The importance of nonmetal doping with transition metal nanoparticles to create new active surface areas and enhance catalytic activity is also discussed. Elemental doping and defect engineering are highlighted as two crucial strategies to enhance the performance of these compounds in HER applications. This review presents a comprehensive and recent analysis of the developments in carbon-based transition metal compounds and supported layered double hydroxides (LDHs) for HER, emphasizing the significant challenges and opportunities in this promising field. Additionally, this review conducts a comparative analysis with other papers, highlighting both similarities and differences, and provides new insights into electrochemical water splitting processes. It underscores the potential for practical applications of this knowledge.