Sulfur vacancy in SnS2 nanoflake adjusted by precursor and improved photocatalytic performance

Abstract

SnS2 with nanoflake-based microstructure and different concentrations of sulfur vacancy (SV) has been synthesized. The valence state of tin cation in the precursors is found to be closely related to the SV concentration in SnS2 nanoflake. SnS2 nanoflake with unsaturated tin cation in tin salt precursor (SnCl2·2H2O) favors to create SV. Sufficient SV is found to bring about a number of advantages such as smaller energy band gap, larger electrochemical active surface Area (ECSA), improved light absorption and separation efficiency of photogenerated charge carriers, which results in superior photocatalytic activities for degradation of RhB and CO2. SnS2 with more sulfur vacancies exhibits better photocatalytic activity for RhB degradation with a degradation rate 1.02×10−2min−1 and for CO2 reduction with an average CO production rate 2.44μmol∙g−1∙h−1. Above results not only reveal the importance of defect engineering, but also provide valuable guide to develop effective metal-sulfide photocatalysts for organic pollutant degradation and CO2 reduction.