Non-noble-metal TiC-nanoparticle-promoted charge separation and photocatalytic degradation performance on Bi2O3 microrods: degradation pathway and mechanism investigation

Abstract

In the present work, a promising binary TiC/Bi₂O₃ photocatalyst was obtained via a simple hydrothermal route. In the photodegradation experiment of acid orange 7 (AO7) and tetracycline (TC) irradiated by simulated sunlight, the attachment of TiC nanoparticles on the Bi₂O₃ microrods leads to an obvious improvement in the photocatalytic removal properties of the Bi₂O₃ microrods. The optimal removal efficiency of AO7 was achieved by the 7.5%TiC/Bi₂O₃ sample, which results in about 91.5% dye removal within 75 min of reaction. Meanwhile, the 7.5%TiC/Bi₂O₃ sample also exhibits favorable photodegradation performance for the degradation of TC, leading to about ∼76.9% TC being degraded after 75 min of irradiation. More importantly, the degradation pathways of AO7 and toxicity analysis of the intermediate products were performed based on liquid chromatography–mass spectrometry detection and theoretical simulation. The superior photocatalytic behavior of the TiC/Bi₂O₃ composite is attributed to the effective separation and migration of photoexcited electrons and holes in the heterojunction, where the TiC nanoparticles act as an acceptor of photoexcited electrons.