Enhancing the MoS2/MoO3/ZnS/Zn-Heterojunction catalyst's photocatalytic performance for water organic pollutants

Abstract

Pure and lightly Zn-doped (MoS2)0.97Zn0.03 powdered samples have been prepared by a simple economic method, structurally analysed by XRD, FT-IR, XPS, SEM& EDX, and optically characterised using optical diffuse reflectance spectroscopy. XRD analysis of the heat-treated Zn: MoS2 product revealed the formation of different multi-heterojunction semiconducting MoS2, MoO3 and barely visible ZnS components beside the metal-Zn element which were confirmed by FT-IR, XPS& EDX. The crystallite size for MoS2 samples decreased from 400.465 to 326.179 nm of (MoS2)0.97Zn0.03 , while the MoO3 and Zn constituents exhibit lower values of 108.884 & 8.045 nm, respectively. Their porosity percentages of ∼60%–67% are relatively high and beneficial for the photocatalytic process. The optical study showed a indirect allowed band gap with energy values of 1.2 and 0.9 eV for undoped and Zn doped, respectively. The photocatalytic study has been performed at different MB concentrations (10–20 ppm), and catalyst amounts (0.04–0.1 g) under dark, UV, and Vis irradiations assisted by pH and/or ultrasonic piezoelectric potential. The current enhanced result of 99.3% efficiency and a high performance figure of merit of ∼1045 min−1 were achieved in 20 s for (MoS2)0.97Zn0.03 with the capability of reusability.