Edge-enriched laminar hexagonal (2H) MoSe2-anchored sulfur vacancies-rich ReS2 nanoflowers for boosted light-to-hydrogen conversion

Abstract

Developing innovative S-scheme photocatalytic systems with highly active catalysts are of huge interest in converting solar energy into hydrogen in a sustainable manner. Herein, sulfur vacancies (Sv)-rich hierarchical flower-like ReS2-hybridized laminar hexagonal (2H) MoSe2 (2H-MoSe2) were constructed for water splitting. Systematic studies show that interfacial chemical interaction of Mo–S bond and built-in electric field induce the S-scheme charge transfer mode, as verified by the generated superoxide radicals, band structures, and density functional theory calculation. With the intense cooperative effects of Mo–S bonds, S-vacancies, and internal electric field, the optimized Sv-ReS2/2H-MoSe2 heterojunction concurrently attains populated exposed active sites, superior electron-hole separation efficiency, and intensive affinity to reactant water molecules, achieving a maximum hydrogen production rate of 78.2 μmol/h with an apparent quantum yield of 9.3% at 420 nm, which is approximately 5.9-fold greater than pristine ReS2. This work paves a new avenue to engineering S-scheme catalysts for sustainable solar-to-fuel conversion.