Highly efficient photocatalytic removal of concentrated PEX, PAX and SIPX xanthates collectors by an immobilized nanostructured g-C3N4/ZnO low power backlighted module

Abstract

This study provides a pathway to practical application of graphitic carbon nitride (g-C3N4)-based photocatalysts as a promising next-generation polymeric-based environmentally friendly two dimentional (2D) nano-photocatalyst under real conditions in a dark medium at a very high concentration of xanthates collectors. Ultra-low amounts photocatalyst loading, low-power visible LED light source and strong light-photocatalyst coupling also play important roles in practical photodegradation of pollutants. Herein, immobilized low metal-oxide loaded (LMOL) g-C3N4/ZnO backlighted photocatalytic module with 0.6 ± 0.1 g/m2 g-C3N4/ZnO loading was developed to degrade dark dyes, potassium ethyl xanthate (PEX), potassium amyl xanthate (PAX) and sodium isopropyl xanthate (SIPX) collectors. The LMOL g-C3N4/ZnO nanostructures were investigated by XRD, UV–vis, PL, FE-SEM and XPS. After an efficient decomposing of dark methylene blue and methyl orange, the photodegradation of PEX, PAX and SIPX was examined and the photodegradation mechanism of the xanthates was also investigated. The degradation efficiency of the photocatalytic module was up to 95 %, which remained unchanged after several cycles. The efficient photocatalytic removal of xanthates is due to the effective light-photocatalyst coupling in dark media and also well-established e-/h+ generation and separation in LMOL g-C3N4/ZnO heterojunction.