CQDs modified Bi2MoO6/CuS p-n heterojunction photocatalytic efficient degradation of tetracycline

Photocatalytic technology, as one of the most promising environmental remediation tools, has a wide range of applications in the field of removing antibiotic-based pollutants from wastewater. Therefore, to obtain efficient green and inexpensive photocatalysts, a p-n type Bi2MoO6/CuS composite photocatalyst modified by lignin carbon quantum dots (CQDs) was successfully prepared by solvothermal in situ co-precipitation in this study. It was used to achieve efficient photocatalytic degradation of tetracyclic hydrochloride antibiotics (TCH). The composites were systematically characterized by XRD, FTIR, XPS, SEM, TEM, EIS, nitrogen adsorption-desorption test, and UV-Vis DRS regarding crystal structure, microscopic morphology, and photoelectric properties. The results showed that the prepared samples had good crystallinity and high purity. The photocatalytic degradation experiments further demonstrated that the Bi2MoO6/CuS composites modified by CQDs exhibited excellent photocatalytic activity compared to Bi2MoO6 and CuS monomers wherein CQDs@Bi2MoO6/CuS 2 was the most effective, with a TCH removal of 96.98% and a degradation rate constant (K) of 0.04405 min(-1) after 60 min of light exposure. The TCH removal could be maintained at 78.25% after four cycles. The ESR and LC-MS experiments demonstrated that h(+) and <middle dot>O-2(-) were the main active substances for photocatalytic degradation of TCH. This work provides an efficient catalyst for TCH removal and offers new ideas for applying p-n heterojunction composites in photocatalysis.