Rational Design of Carbon-Doped Carbon Nitride/Bi12O17Cl2 Composites: A Promising Candidate Photocatalyst for Boosting Visible-Light-Driven Photocatalytic Degradation of Tetracycline

Many recent advances based on 2D materials have opened new possibilities in photocatalysis. In this paper, a new 2D semiconductor composite consisting of carbon-doped carbon nitride (denoted as CCN) layers and Bi12O17Cl2 layers was designed via an in situ method. A supramolecular chemistry approach was employed to form CCN by using the hydrogen-bonded melamine-cyanuric acid and barbituric acid, and Bi12O17Cl2 layers were obtained by using a moderate solvothermal method. CCN/Bi12O17Cl2 composite had superior photocatalytic performance for degrading antibiotic tetracycline (TC) under visible-light irradiation. The degradation rate constant of 20%CCN/Bi12O17Cl2 is 0.0409 min(-1), which is approximately 2.9-, 1.5-, and 32.1-fold those of pristine Bi12O17Cl2, CCN, and BiOCl, respectively. Electrochemical measurements showed that CCN/Bi12O17Cl2 composite has high photogenerated charge carrier separation efficiency. According to the trapping and electron spin resonance results, superoxide radicals and holes were the main active radicals in the degradation of TC. The enhanced photocatalytic activity of CCN/Bi12O17Cl2 can be attributed to enhanced charge separation. It is expected that the CCN/Bi12O17Cl2 composite could be utilized as visible-light photocatalyst for other environmental applications.