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 Bi 12 O 17 Cl 2 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 Bi 12 O 17 Cl 2 layers were obtained by using a moderate solvothermal method. CCN/Bi 12 O 17 Cl 2 composite had superior photocatalytic performance for degrading antibiotic tetracycline (TC) under visible-light irradiation. The degradation rate constant of 20%CCN/Bi 12 O 17 Cl 2 is 0.0409 min –1, which is approximately 2.9-, 1.5-, and 32.1-fold those of pristine Bi 12 O 17 Cl 2, CCN, and BiOCl, respectively. Electrochemical measurements showed that CCN/Bi 12 O 17 Cl 2 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/Bi 12 O 17 Cl 2 can be attributed to enhanced charge separation. It is expected that the CCN/Bi 12 O 17 Cl 2 composite could be utilized as visible-light photocatalyst for other environmental applications.