Preparation of titanium dioxide modified biomass polymer microspheres for photocatalytic degradation of rhodamine-B dye and tetracycline

Abstract

Photocatalysis, in which carcinogenic compounds are decomposed into harmless products, is the most promising method for the eco-friendly degradation of wastewater pollutants. This study investigated a novel bio-based polymeric microsphere photocatalyst produced via the precipitation polymerization of widely available biomass-derived phenylpropenes trans-anethole (ANE) and N-phenylmaleimide (N-PMI). Amino-modified TiO2 nanoparticles were grafted onto the surfaces of the microspheres, thereby producing Poly[ANE+N-PMI]-TiO2 microspheres using photocatalysis. The microspheres were used as photocatalysts for the degradation of rhodamine B (RhB) dye and tetracycline (TC) antibiotics in wastewater, where 95% and 97% degradation rates were achieved for 50 mg·L-1 RhB and 100 mg·L-1 TC, respectively. The microsphere photocatalyst exhibited high stability and recyclability, and maintained excellent photocatalytic performance during continued cycling. Kinetic studies demonstrated that the photocatalytic degradation of RhB and TC proceeded according to a pseudo-first-order kinetics model. Furthermore, superoxide free radicals (·O2−) and hydroxyl radicals (·OH) were the primary and secondary reactive species during photo-degradation. Overall, the excellent performance of the simple TiO2-based photocatalyst was clearly demonstrated, and its numerous advantages, such as low energy consumption, low cost, non-toxicity, and environmental friendliness, highlight its promising practical applications.