Synthesis of Cu-Doped TiO2 Nanocatalyst for the Enhanced Photocatalytic Degradation and Mineralization of Gabapentin under UVA/LED Irradiation: Characterization and Photocatalytic Activity

Light-harvesting of titanium oxide (TiO2) was enhanced by copper (Cu) doping, and its performance was evaluated by gabapentin (GBP) degradation under UVA-LED irradiation. The morphology and structure of TiO2 and Cu-TiO2 were characterized using XRD, FTIR, FE-SEM, EDX, TEM, PL, DRS, and BET analysis. The complete degradation of 10 mg/L GBP was obtained in the developed photocatalytic process under the optimal conditions: catalyst loading, 0.4 g/L; pH solution, 8; and reaction time, 20 min. The reactive species trapping was studied to identify the degradation mechanism in this system. Among the water matrix experiments, phosphate (PO43−) anion indicated an inverse effect in increasing efficiency. Finally, the main intermediates generation during the GBP degradation was investigated based on LC-MS analysis, and a decomposition pathway was proposed. Accordingly, doping TiO2 with Cu resulted in the development of a UVA-activated photocatalyst for efficiently degrading and mineralizing GBP as a model of a pharmaceutical compound.