Z-scheme Cu0.5Cd0.5S/MoO3-x photocatalyst with synergistic localized surface plasmon resonance effect for efficient photocatalytic hydrogen evolution

Abstract

In this study, we designed and fabricated a Z-scheme Cu0.5Cd0.5S/MoO3-x (CMO) heterojunction with localized surface plasmon resonance (LSPR) effect for efficient photocatalytic hydrogen evolution. The oxygen vacancies (OVs) in MoO3-x induced Schottky-barrier-free LSPR for the generation of hot electrons. The architecture of transition-metal-substituted solid solution (Cu0.5Cd0.5S, CCS) downshifted the conduction band (CB) of CdS from −0.45 eV to −0.38 eV and upshifted the valence band (VB) from 1.65 eV to 1.54 eV, respectively, weakening the interface barrier of the hot electrons transition from MoO3-x to CCS and enhancing the Coulomb interaction between the electrons of MoO3-x and the holes of CCS. Benefiting from the cooperation between Z-scheme heterojunction and LSPR effect, the hydrogen evolution rate (HER) of the optimized CMO was 19.28 mmol·g−1·h−1 under visible light with an apparent quantum yield (AQY) of 10.8 % at 420 nm, which was 3.0 and 1.4 times that of the CCS and CCS/MoO3. Moreover, the HER of CMO still reached 43.57 μmol·g−1·h−1 at 600 nm. This work paved a new path for efficient photocatalysts H2 evolution by coupling Z-scheme heterojunction and non-noble-metal LSPR effect.