“Optimizing solar-driven dye degradation: Ag6Si2O7/WSe2 nanocomposites via S-scheme photocatalysis”

Abstract

Background

The implementation of semiconductor photocatalyst engineering offers a promising solution to combat water pollution and energy crises by efficiently converting solar energy into chemical energy for organic dye decomposition.

Methods

By hydrothermal method nanostructures of Ag₆Si₂O₇/WSe₂ were synthesized and investigated their effectiveness in solar-driven photo-degradation of rhodamine B (RhB) and Methylene Blue (MB) dyes. Ag₆Si₂O₇/WSe₂ nanocomposites were developed by varying the weight percentage of WSe₂ from 0 to 25 % in the Ag₆Si₂O₇ matrix. The physicochemical properties of the nanocomposites were analyzed by using various techniques such as XRD, FE-SEM, and TEM/HRTEM. Additionally, the optical properties were investigated using UV–Vis, PL, and EIS.

Significant findings

According to the BET study, the AgWS-c composite exhibited the highest BET surface area at 47.56 m²/g and outperformed other composites by achieving degradation rates of 96.24 % for RhB and 97.70 % for MB within 50 min. The rate constant of AgWS-c (0.0513 min⁻¹) was 16.54 times higher than that of Ag₆Si₂O₇ and 2.63 times more than WSe₂ pristine, indicating its efficacy in dye degradation. ESR analysis assessed ROS species activity, LC/MS identified degradation intermediates, and a degradation mechanism pathway for RhB was proposed. The findings suggest that AgWS-c is a promising candidate for rapid and efficient wastewater treatment.