Defect-engineered dual Z-scheme core-shell MoS2/WO3-x/AgBiS2 for antibiotic and dyes degradation in photo and night catalysis: Mechanism and pathways

Abstract

Water pollution caused by antibiotics and synthetic dyes and imminent energy crises due to limited fossil fuel resources are issues of contemporary decades. Herein, we address them by enabling the multifunctionality in dual Z-scheme MoS₂/WO_3-x/AgBiS₂ across photolysis, photo Fenton-like, and night catalysis. Defect, basal, and facet-engineered WO_3-x is modified with MoS₂ and AgBiS₂, which extended its photoresponse from the UV-NIR region, inhibited carrier recombination, and reduced carrier transfer resistance. The electric field rearrangement leads to a flow of electrons from MoS₂ and AgBiS₂ to WO_3-x and intensifies the electron population, which is crucial for night catalysis. When MoS₂/WO_3-x/AgBiS₂ was employed against doxycycline hydrochloride (DOXH), it removed 95.65, 81.11, and 77.92 % of DOXH in 100 min during photo-Fenton (PFR), night-Fenton (NFR), and photocatalytic (PCR) reactions, respectively. It also effectively removed 91.91, 98.17, 99.01, and 98.99 % of rhodamine B (RhB), Congo red (CR), methylene blue (MB), and methylene orange (MO) in Fenton reactions, respectively. ESR analysis consolidates the ROS generation feature of MoS₂/WO_3-x/AgBiS₂ using H₂O₂ with and without irradiation. This work provides a strategy to eliminate the deficiencies of WO_3-x and is conducive to the evolution of applications seeking to combat environmental and energy crises.

Keywords: DOXH; Fenton reaction; Night catalysis; Photocatalysis; RhB; Z-scheme.