Fabrication of ternary Ag/La-black TiO2−x photocatalyst with enhanced visible-light photocatalytic activity for tetracycline degradation

The ternary Ag/La-TiO2−x heterojunctions were prepared successfully and was used for the photocatalytic degradation of tetracycline (TC) under visible light irradiation. Using numerous techniques, the factors affecting the structure, morphology and optoelectronic properties of Ag/La-TiO2−x composites were systematically discussed. Due to the higher photoinduced charge separation efficiency, the as-prepared composites possessed the excellent visible-light photocatalytic degradation activity of TC. The ·O2- was the primary active species as well as the h+ and •OH were the essential active species during the process of photocatalytic degradation. Moreover, the mechanism of photocatalytic degradation of TC by Ag/La-TiO2−x composites was given, and the degradation pathways of TC during the process of photocatalytic were also considered. Based on the synergism of the introduction of Ti3+ and Ov, the inhibition charges recombination caused of La and the SPR effect of Ag nanoparticles, the photocatalytic performance of the Ag/La-TiO2−x composite observably improved. Due to the excellent photocatalytic properties and stability, the Ag/La-TiO2−x hybrid composites are expected to have significant potential applications in energy conversion and environmental remediation.