Facile decoration of CdS nanoparticles on TiO2: robust photocatalytic activity under LED illumination

Abstract

Abstract A facile approach is presented to obtain visible-light-active TiO2/CdS nanocomposites with visible-light photocatalytic activity. Ordered nanospheres of TiO2 (with anatase as the main crystalline phase) were synthesized using evaporation-induced self-assembly (EIS) with P123 block polymer without any hazardous additives. Then, a rapid microwave (MW) protocol was used to obtain visible-light-absorbing nanocomposites between TiO2 and CdS in just 10 s. Based on Rietveld refinements of X-ray diffractrograms and elemental analysis it was found that nanoparticles of CdS are mainly decorated between the nanospheres of TiO2, which can simultaneously improve light absorption and suppress the unwanted photo-corrosion effects. The prepared nanocomposites were put to test for the removal of malachite green as a model pollutant from aqueous media under irradiation. The results revealed, that excessive loading results in unwanted surface covering and less than ideal activity, but for the sample with optimized loading, about 86 and 77% of the pollutant was degraded after 100 min of illumination at room temperature under the xenon short-arc and LED illumination, respectively.