Recent Advances in Doping Strategies to Improve Electrocatalytic Hydrogen Evolution Performance of Molybdenum Disulfide

The exhaustion of fossil fuels and resultant pollution issues have prompted the world to look to clean, nonpolluting hydrogen energy. The promising approach of the electrocatalytic hydrogen evolution reaction (HER) presents a solution for addressing energy and environmental challenges. Consequently, creating high-performance and cost-effective electrocatalysts is essential for the efficient decomposition of water. Molybdenum disulfide (MoS2) has emerged as the most promising among potential electrocatalysts to replace platinum. However, only the edge-site of MoS2 is active for HER due to the MoS2 semiconductive nature and large inactive basal planes. Doping various substances, which significantly improves HER activity, can enhance MoS2's physical and chemical properties. Our Review encapsulates the latest strategies and research advancements in choosing heteroatomic-doped MoS2 for hydrogen production. Various doping elements impart unique physical and chemical properties to MoS2. Specifically, doping with noble metals (e.g., Ag, Pt, Ru, Pd, Rh) and transition metals (e.g., Fe, V, Ni, Mn, Co, Zn, W), as well as codoping with multiple metal atoms (e.g., Cu-Pd, Pt-Te, Co-Nb, Ni-Co), can significantly enhance conductivity and introduce new active sites. These dopants are recognized for activating the basal plane of MoS2, thereby enhancing the HER activity. Furthermore, doping with nonmetallic elements (e.g., N, F, P, An, O) and their codoping combinations (e.g., O-P, N-F, Se-O), as well as the codoping of nonmetal and metal atoms (e.g., Co-Se, Co-P, N-Pt, Ru-O), is crucial for inducing phase conversions and improving stability. Each dopant contributes distinctively, either by enhancing the stability of MoS2, serving as a catalytic site, or broadening the pH range for effective HER. In this discussion, we further explore the current challenges and outlook of this promising area. Furthermore, we discuss existing challenges and promising guidelines for future research on the MoS2-based catalyst, offering advice to translation from laboratory research to large-scale industrial hydrogen production.