Harnessing multifunctional antimony doped Tin (IV) sulfide nanosheets for chlorpyrifos degradation and hydrogen evolution

Abstract

Multifunctional photocatalysts are vital for advancing environmental sustainability and clean energy. The hydrothermal method helped in optimized antimony (Sb) doping in the Tin (IV) sulfide (SnS2) lattice, increasing surface area with nanosheet assortment, as confirmed by Scanning Electron Microscopy and BET (Brunauer, Emmett and Teller) analysis. Moreover, the Fermi level shift towards conduction band within the semiconductor, increasing free electron concentration which enhanced conductivity and altered electronic properties. Photocatalysts were evaluated for Chlorpyrifos pesticide degradation, with studies conducted on photocatalytic parameters such as catalyst dosage, pesticide concentration, and pH to ascertain optimal degradation conditions. The 6 wt% Sb-doped SnS2 (6Sb:SnS2) demonstrated highest degradation efficiency within 60 min and degradation obeyed a pseudo first-order kinetic model with a rate constant of 0.0349 min- 1. The degradation pathway of Chlorpyrifos and its transformation products was elucidated through High-Performance Liquid Chromatography-tandem mass spectroscopy. In addition, Sb doping empowers the surface traps and hydrophilicity of photocatalysts towards successful interaction between photogenerated electrons/holes with adsorbed oxidizable/reducible species. Moreover, 6Sb:SnS2 exhibited superior hydrogen evolution of 214.39 mu molg- 1h- 1, along with improved stability. Significantly, 6Sb:SnS2 attained Apparent Quantum Yield (AQY400 nm) of 39.49 % attributed to the doping induced band structure modification of SnS2 to match the hydrogen ion reduction potential.