Fabrication of ternary Bi2S3/BiVO4/g-C3N4 composite material for enhanced photocatalytic degradation of antibiotics

Antibiotic contaminants are known to pose a serious threat to the human health and environment, thus a great deal of effort has been made to develop destruction technologies for antibiotic treatment in the water environment. Photocatalytic oxidation technology is regarded as one of the most promising strategies for decomposing antibiotics from water. In this work, ternary Bi2S3/BiVO4/g-C3N4 composite material is dexterously designed and synthesized to obtain the enhanced photocatalytic performance for tetracycline (TC) degradation via a facile strategy. Therein, the optimal Bi2S3/BiVO4/g-C3N4 material showed the excellent degradation efficiency under visible light irradiation in comparison to the nude g-C3N4 and BiVO4/g-C3N4 photocatalysts, and it can continuously degrade the TC pollutant in 90 min and achieve a degradation percentage of 80.7 %. The designed materials can not only intensify photo-absorption efficiency of g-C3N4 material, but also improve its separation and transfer efficiency of photo-generated charge carriers, which is attributed to the incorporation of BiVO4 and Bi2S3 materials. The active species trapping experiments verified that the superoxide radicals (center dot O-2(-)) is the main active species, and holes (h(+)) also played an important role in the Bi2S3/BiVO4/g-C3N4 system. Furthermore, the photoelectrochemical measurement (PEC) clearly demonstrated that the incorporation of BiVO4 and Bi2S3 materials could accelerate the separation and transfer of photo-generated electron and hole pairs. As expected, our present work could spark new inspirations to further develop the efficient photocatalysts for solar energy conversion.