Fabrication of a Z-scheme nanocomposite photocatalyst for enhanced photocatalytic degradation of ibuprofen under visible light irradiation

In this study, a simple hydrothermal method was used to prepare a Z-scheme CdS/Fe3O4/TiO2 nanocomposite photocatalyst for the degradation of ibuprofen under visible light. The fabricated photocatalyst has been comprehensively characterized. It has a uniformly distributed spherical shape, excellent long-wavelength light absorption ability, rapid electron separation and Z-scheme electron transfer. Fe3O4 in the photocatalyst promotes light absorption and the formation of Z-scheme heterojunction as an electron mediator. Under the optimal atomic ratio, 94.2% of ibuprofen can be decomposed after visible light irradiation for 180 min in the presence of CdS/Fe3O4/TiO2 nanocomposite photocatalyst. The dominant reactive species accounting for ibuprofen degradation are holes (h(+)) and hydroxyl radicals (center dot OH). After reaction, the photocatalyst can be easily recollected through magnetic separation. Although the photocatalytic efficiency of reused CdS/Fe3O4/TiO2 nanocomposite photocatalyst decreased, it kept stable good performance (around 75%) after reused for more than 3 cycles. Overall, this study provides an easy method to synthesize a novel magnetic photocatalyst for the photocatalytic degradation of emerging contaminates under visible light.