Recent advances in transition metals- based materials as electrocatalysts for water splitting

There has been a significant amount of interest in developing productive solutions for clean and sustainable hydrogen energy, and one of the most promising strategies involves the electrolysis of water to produce hy-drogen. While Pt-group metals are currently the most efficient electrocatalysts for the hydrogen evolution re-action (HER) due to their low overpotential to produce high cathodic current densities, their widespread use is greatly constrained by their high price and unavailability. Recent investigations into transition metal compounds as HER catalysts have shown promise, but creating highly active catalysts based on inexpensive and readily available materials has proven to be a difficult task. Researchers have recently been intrigued by noteworthy breakthroughs involving 2D heterostructure transition metals electrocatalysts with a low overpotential towards HER, which are reviewed in this feature article, along with the performance of electrocatalysts for HER on transition metal compounds over the previous few years, elemental doping, defect engineering, and some sig-nificant issues and difficulties in the study of HER.