Investigation of EG-Bi2S3 nanorods photocatalytic activity under visible light for dye degradation from aquatic system

Abstract

Bi₂S₃, 5 ml EG-Bi₂S₃, and 10 ml EG-Bi₂S₃ were synthesized by employing solvothermal route. X-ray diffraction, UV-vis absorption, photoluminescence, Raman, scanning electron microscopic studies confirmed the structural, optical, morphological behaviors. The XRD pattern of Bi₂S₃, 5 ml EG-Bi₂S₃, and 10 ml EG-Bi₂S₃ was correlated well with JCPDS # 65-2435. The crystallite size was found to be 57, 49, and 40 nm. The photoluminescence spectra showed semiconducting property of prepared Bi₂S₃, 5 ml EG-Bi₂S₃, and 10 ml EG-Bi₂S₃. The absorption spectra of Bi₂S₃, 5 ml EG-Bi₂S₃, and 10 ml EG-Bi₂S₃ nanorods were well matched with the spectra of a previous report. The bandgap values of Bi₂S₃, 5 ml EG-Bi₂S₃, and 10 ml EG-Bi₂S₃ were calculated to be 1.56, 1.45, and 1.3 eV in reducing order. The morphology of Bi₂S₃, 5 ml EG-Bi₂S₃, and 10 ml EG-Bi₂S₃ samples showed the development of nanorods. The 10 ml EG-Bi₂S₃ sample showed better development of nanorods with the addition of ethylene glycol. The agglomeration was considerably reduced with the mixing of solvent. Bi₂S₃, 5 ml EG-Bi₂S₃, and 10 ml EG-Bi₂S₃ catalysts were added to the methylene blue dye solution and its photocatalytic properties were investigated by reducing toxic pollutants under light. The 10 ml EG-Bi₂S₃ sample with neutral pH and 0.1 g of catalyst was added and investigated which showed 86% of efficiency towards dye degradation. The narrow bandgap, defined morphology of 10 ml EG-Bi₂S₃, made a positive result towards efficient photocatalytic activity.

Keywords: Bandgap; Bi2S3; Ethylene glycol; Methylene blue; Nanorods; Solvothermal; Visible light.