Exploring the physical properties of pristine γ-In2S3 and its influence on Ba doping for photocatalytic degradation of 2,4-D herbicide

Abstract

In this work, pristine γ-In2S3 nanoribbons were synthesized using a facile solution process and uniquely doped with Ba for the first time. XRD and Raman spectroscopy confirmed the formation of pure-phase γ-In2S3 and successful Ba doping. XPS further validated the presence of Ba 3d core level with In 3d and S 2p after the inclusion of Ba. FESEM and HRTEM images showed the formation of nanoribbons, with the width increasing from 60 to 100 nm after doping. The anticipated stoichiometry of In and S, with approximately 2 atomic % of Ba, was confirmed by EDS. After Ba-doping, the bandgap was narrowed from 3.66 eV to 3.03 eV, and the charge carrier recombination was substantially reduced, as witnessed by PL and EIS. The potential of pristine γ-In2S3 and Ba-doped γ-In2S3 as new photocatalysts was highlighted in this study, exploring their applicability for the photodegradation of the stubborn herbicide 2,4-dichlorophenoxyacetic acid (2,4-D). The materials demonstrated impressive performances, achieving degradation efficiencies of 77.08 % and 94.15 % before and after doping, respectively, within 210 min. The scavenging tests revealed a significant contribution of O2•− and •OH for 2,4-D degradation using Ba-doped γ-In2S3 photocatalyst. Besides photocatalysts used in this study demonstrated excellent stability after four cycles. These findings suggest a promising approach for developing cost-effective semiconductors to remove persistent herbicides.