Enhanced photocatalytic reduction of CO2 using a novel 2D/0D SnS2/CeO2 binary photocatalyst with Z-scheme heterojunction and oxygen vacancy

Abstract

In this work, suitable band gap width, strong photo-response to visible light, and a high photogenerated carrier density offered by an important member of layered sulfides, SnS2, were kept in view for designing and producing a highly effective photocatalyst for CO2 reduction. Hence, SnS2/CeO2 heterojunction composite photocatalysts were triumphally fabricated by a facile in situ hydrothermal synthesis method, combining advantages of the built-in electric field and oxygen vacancies of two materials. Various characterization techniques were exploited to scrutinize the photocatalyst’s structure and confirm that the carrier transport efficiency and photocatalytic performance are enhanced by the synergistic impact of the heterojunction structure and presence of oxygen vacancies. Owing to the successful loading of zero-dimensional CeO2 nanoparticles onto two-dimensional SnS2 nanosheets, the 2D/0D structure improves the photo-response range of the composites and provides faster electron transfer rates. The composite material maintained the hydrophobic characteristic of single SnS2, while inhibiting the hydrophilic property of single CeO2. As a result, CO and CH4 yields of prepared binary Z-type heterojunction photocatalysts are 24.6 and 4.4 folds higher than those of single SnS2, respectively. This innovative study will contribute to exploration of SnS2-based photocatalytic materials and provide a new feasible direction for light energy-driven CO2 reduction.

Keywords

• Photocatalysis
• SnS2-based compounds
• CO2 reduction
• Heterojunction
• Oxygen vacancies