Photothermal-coupled solar photocatalytic CO ₂ reduction with high efficiency and selectivity on a MoO _{3− x} @ZnIn ₂S ₄ core–shell S-scheme heterojunction

Abstract

An S-scheme heterojunction of core–shell MoO _{3− x} @ZnIn ₂S ₄ is first constructed for photothermal-coupled solar photocatalytic CO ₂ reduction with high efficiency and selectivity.

Abstract

Photocatalytic technology to convert CO ₂ into a chemical fuel is one of the most promising ways to alleviate the greenhouse effect. However, due to the low photocatalytic efficiency and poor product selectivity, the application of photocatalytic CO ₂ reduction is seriously limited. In this study, a MoO _{3− x} @ZnIn ₂S ₄ composite with a core–shell structure is designed for the first time, and the combination of an S-scheme heterojunction and photothermal synergistic catalysis is successfully applied to full-spectrum solar photocatalytic CO ₂ reduction. Thanks to the cooperative effects of its unique hierarchical architecture, close interface contact, special charge-transfer pathway and high photothermal efficiency, the MoO _{3− x} @ZnIn ₂S ₄ composite photocatalyst exhibits average yields of CO and CH ₄ up to 4.65 and 28.3 μmol g ⁻¹ h ⁻¹ under UV-Vis-IR irradiation without a sacrificial agent and cocatalyst. The average yield of CH ₄ is 19.4 and 11.7 times that of pure MoO _{3− x} and ZnIn ₂S ₄ samples, respectively. Moreover, it also shows a CH ₄ selectivity as high as 85.89%.