Facile synthesis of black TiO2@CeO2 heterojunction microparticles toward efficient simultaneous removal of antibiotics and dyes

Using tetrabutyl titanate and cerium nitrate hexahydrate as raw materials, a novel kind of black TiO 2 @CeO 2 heterojunction microparticles were rationally synthesized via a mild one-pot solvothermal strategy coupled with calcination in inert atmosphere. Research results indicated that the black TiO 2 @CeO 2 microparticles possessed a narrowed bandgap of 1.62 eV and remarkably enlarged specific surface area. Benefitting from the synergistic effect of TiO 2 and CeO 2 , the composite microparticles exhibited remarkable catalytic degradation performance toward efficient removal of typical synthetic organic dyes and various antibiotics in aqueous solutions. The removal efficiencies of various antibiotics and dyes reached more than 75% within 60 min and more than 65% within 90 min, respectively. In particular, the black TiO 2 @CeO 2 microparticles achieved an overall TCH removal efficiency of 93.9% within 60 min (including dark-adsorption contribution). The apparent rate constant calculated over the subsequent 30 min of illumination was 0.0348 min -1 , demonstrating its favorable photocatalytic activity. Additionally, the dominant active species and charge transfer pathway during photocatalysis were investigated to reveal the intrinsic reaction mechanism. This work provides a facile strategy for constructing high-efficiency composite photocatalysts toward water environmental remediation.