Pt nanoparticles-modified WO3@TiO2 core–shell ternary nanocomposites as stable and efficient photocatalysts in tetracycline degradation

Core–shell structure photocatalysts have attracted extensive attention in the field of wastewater treatment because of their desirable capacity of efficient charge separation. In this study, a novel Pt nanoparticles-modified WO3@TiO2 core–shell ternary structure was synthesized and its photocatalytic property was evaluated by degrading 30 ppm of tetracycline (TC) under simulated solar light. It was found that the optimal Pt-WO3@TiO2 ternary structures exhibit extremely superior performance in photocurrent response (30 times higher) and photocatalysis (10 times higher) compared to the pristine WO3 nanorods. The enhanced photocatalytic performance is attributed to the long lifetime of charge carriers and the increment of oxygen vacancies generated by introducing Pt nanoparticles. The radicals trapping experiments verified a two-step TC photodegradation process which can be ascribed to the existence of superoxide radicals ( $$\cdot {\text{O}}₂ ^- $$ ) and holes (h+). This work may shed light on the design of novel ternary core–shell structure for efficient degradation of TC under solar light.