Double-plasmonic-coupled heterojunction photocatalysts for highly-efficient full-spectrum-light-driven H₂ evolution from ammonia borane

Methods to enhance the full-spectrum-light-driven water splitting for H₂ evolution remain one of the critically important issues to explore advanced photocatalysts. In this study, we present a novel double-plasmon-coupled semiconductor heterojunction photocatalyst with a large number of oxygen vacancies, produced via a simple two-step solvothermal process. These materials represent a new model system to study the kinetics process and catalytic activity of ammonia borane hydrolytic dehydrogenation in a full-spectrum-light-driven plasmonic semiconductor heterostructure. Upon irradiation with full-spectrum light, the resultant photocatalysts are capable of delivering H₂ generation rate up to 13,031 μmol g^-1h⁻¹, which is ∼6 times greater than that of pristine MoO_3-x counterpart. The excellent photocatalytic behavior is primarily attributed to the improved carrier separation, increased light absorption, and enhanced generation of “hot electrons”, enabled by a synergistic photo- and thermo-catalytic effect. Consequently, the high performance of the novel photocatalyst derives from the design of a double-plasmonic-coupling effect and the photocatalyst containing Type-Ⅱ heterojunctions.