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.

CuS、ZnS及其p-n CuS/ZnS异质结光催化剂通过一种创新的单罐燃烧法合成。在本研究中，罗丹明B（RhB）染料被用作模型污染物，并绘制了其校准曲线。所合成的单一催化剂以及二元纳米复合材料随后采用多种技术进行了表征，包括X射线衍射（XRD）、X射线荧光（XRF）、扫描电子显微镜-能量色散光谱（SEM-EDS）、透射电子显微镜（TEM）、比表面积（BET）和紫外-可见光谱，据此绘制了相应的Tauc图，并估计了所合成材料的带隙能量。在可见光照射下进行了一项深入的photodegradation研究。通过控制实验测量了光催化的效果。研究了优化参数，如组成催化剂的影响、催化剂负载量效应、初始RhB染料pH值的影响以及初始RhB染料浓度的影响。此外，进行了一项清除剂测试，并提出了p-n CuS/ZnS异质结光催化机理。进一步地，对稳定性和可回收性进行了研究，并在五次可重复使用循环之后捕捉了CuS/ZnS光催化剂的表面形貌。