Bulk and surface engineering of MoO₂ nanoreactors for boosting electrocatalytic water splitting

Electrocatalytic water splitting represents a green technology for efficient hydrogen production, with its core challenge lying in the development of highly efficient, stable, and low-cost electrocatalysts. Molybdenum dioxide (MoO₂) has garnered considerable attention due to its metallic-like high electrical conductivity and the intrinsic adsorption and activation capabilities of its surface-exposed Mo sites towards H⁺, O₂, and H₂O, making it a promising candidate for electrocatalytic water splitting with significant research value and application potential. This review summarizes recent advances in the synthesis methods, bulk and surface modification strategies for MoO₂ nanoreactors to enhance their intrinsic catalytic activity. By integrating in situ characterization techniques with density functional theory (DFT) calculations, the review comprehensively elucidates the dynamic structural evolution and mechanistic insights of MoO₂ nanoreactors during the catalytic process, providing a theoretical foundation for the rational design of MoO₂ nanoreactors. The goal is to develop high-performance MoO₂-based electrocatalysts through bulk and surface engineering to achieve sustainable hydrogen energy production.