Construction of carbon bridged TiO2/CdS tandem Z-scheme heterojunctions toward efficient photocatalytic antibiotic degradation and Cr (VI) reduction

Abstract

Photocatalytic technology is considered to be a promising ways to solve the problems of energy crises and environmental pollution, however, it is a challenge to harvest the full sunlight spectrum in a particulate photocatalyst with highly efficiency. Herein, a hollow TiO2@C/CdS tandem heterojunction with broad light absorption was designed and fabricated. The carbon layer with appropriate work function not only plays the role of bridge to connect TiO2 and CdS for the efficient light absorption, but also promotes the formation of Z-scheme heterojunctions. The phase structure, morphology, chemical composition, optical and electrochemical performance, as well as possible photocatalytic mechanism were systematically investigated. The photocatalytic performances of the as-fabricated tandem heterojunctions for tetracycline hydrochloride (TCH) degradation and Cr (VI) reduction are nearly twice as high as hollow TiO2/CdS. Such reasonable tandem heterojunctions may provide a new route to fabricate particulate photocatalyst with highly efficiency.