Synergistic regulation of TiO2 band structure by Nd and Bi for efficient photocatalytic degradation of ciprofloxacin

Ciprofloxacin (CIP) is a broad-spectrum antibiotic commonly utilized for treating various bacterial infections. Owing to its widespread overuse, CIP is increasingly being identified as an emerging environmental pollutant in various water systems. CIP poses severe ecological risks due to its high toxicity. The inability of traditional water treatment processes to effectively degrade CIP has resulted in its widespread accumulation in wastewater, creating substantial threats to water quality and the health of humans. Photocatalysis has emerged as a successful technique for wastewater treatment of organic contaminants due to its environmental friendliness and stability. As a widely used photocatalyst, titanium dioxide (TiO₂) has garnered significant attention due to sustained catalytic activity and photon utilization rate. However, because of its large band gap, light can only be absorbed in the UV spectrum, which limits its wider use. Get through these restrictions, the energy band structure of TiO₂ was regulated by doping with Nd and Bi, aiming to achieve efficient degradation of ciprofloxacin. TiO₂, Bi-TiO₂ and Nd-Bi-TiO₂ were synthesized by a one-step hydrothermal method, and their methodical investigation of ciprofloxacin (CIP) photocatalytic degradation. The results indicate that the co-doping of Nd and Bi in appropriate amounts alters the structure of TiO₂, notably enhances the specific surface area and photocurrent response, and reduces the band gap width. When the doping amounts of Nd and Bi are 0.5 % and the catalyst dosage is 15 mg. Within 100 min, the CIP photodegradation rate rises from 84.45 % to 100.00 %. According to the first-order reaction kinetics fitting, its rate constant was obtained as 0.0533. A mechanism for the photocatalytic degradation of CIP by Nd/Bi doped TiO₂ was proposed.