Boosted visible-light photocatalysis via p-n heterojunction synergy in 3D tin Sulfide-Graphitic carbon nitride nanohybrids

Abstract

Creating superior nanohybrids with a narrow band gap to harness a larger portion of the solar spectrum is a contemporary necessity. In this study, we utilized a streamlined solvothermal approach to develop a three-dimensional, flower-like tin sulfide (3DF-SnS2) which was integrated atop graphitic nitride layers (g-C3N4). Using a suite of standardized characterization techniques, we delved deep into understanding the design intricacies, structural aspects, photophysical properties, chemical interplay, and surface dynamics of the produced nanohybrids. A noteworthy enhancement in the photocatalytic activity was observed in the p-n heterojunction (3DF-SnS2/g-C3N4) when tested under visible light using the benchmark organic pollutant, Rhodamine B (RhB). When pitted against other nanohybrids from this study, the optimized 3DF-SnS2/g-C3N4 structure displayed a remarkable aptitude for RhB degradation. This was largely due to its adept ability to segregate photo-generated charges efficiently and the harmonious synergy between the 3D and 2D structures, streamlining the charge transfer processes. This commendable photocatalytic efficacy can be attributed to several factors. First, band gap narrowing, the hybrid structure successfully reduces its band gap, allowing for a broader spectrum of solar energy absorption. Second, harmonized charge separation, the interplay between the 3D flower and the 2D sheet structures ensures an effective and efficient separation of photo-generated charges, optimizing their availability for catalytic reactions. 3D/2D Interface Dynamics: The interaction between the 3D floral configuration and the 2D sheet enhances charge mobility, further boosting efficiency. Third, enhanced surface area, the 3D flower-like design of SnS2, in conjunction with the planar nature of g-C3N4, offers abundant active sites for photocatalytic reactions.