CuS-ZnS application in Rhodamine B dye photodegradation under visible-light-irradiation

CuS, ZnS and p-n CuS/ZnS heterojunction photocatalyst were synthesised via a novel one-pot combustion method. Rhodamine B (RhB) dye was used as a model pollutant in this study and its calibration curve was plotted. The synthesised constituent catalysts and the binary nanocomposites were further characterised using various techniques such as XRD, XRF, SEM-EDS, TEM, BET and UV-Vis spectroscopy from which the respective Tauc plots were plotted and the synthesised materials band-gap energies estimated. An in-depth photodegradation study was conducted under visible light irradiation. Control tests were investigated to measure the efficacy of photocatalysis. Optimisation parameters such as the effect of constituent catalysts, effect of catalyst loading, effect of initial RhB dye pH and effect initial RhB dye concentration were investigated. Furthermore, a scavenger test was conducted and a p-n CuS/ZnS heterojunction photocatalytic mechanism was proposed. Moreover, a stability and recyclability test was investigated and the CuS/ZnS photocatalyst surface morphology was captured after the five reusability cycles.