Fabrication and characterisation of B-ZnO nanoparticles for photodegradation of ciprofloxacin antibiotic and textile dyes

Abstract

ABSTRACT The study is centred on the synthesis of B-ZnO photocatalysts via a straightforward mechanochemical combustion method using various weight percentages of B. The synthesised photocatalysts were characterised by XRD, FTIR, FESEM, TEM, XPS, UV-DRS, and BET. Biopersistent ciprofloxacin (CIP) degradation efficiency was investigated with the synthesised B-ZnO. Among the compositions, 4%B-ZnO exhibited the highest photocatalytic efficiency in degrading CIP under both natural sunlight and UV-C. The excellent catalytic activity was attributed to the increased surface area of 4% B-ZnO determined through BET analysis. Under optimised conditions (CIP: 10 mg/L, pH: 6.3, photocatalyst dose: 0.4 g/L), the highest CIP photodegradation efficiency was 92.05% over only 60 min of sunlight irradiation and 90.95% under 80 min of UV-C irradiation. The degradation products of CIP exhibited no antibacterial activity against random soil bacteria. The degradation of CIP followed pseudo-first-order kinetics, with a rate constant of 0.023 min−1. Scavenger tests implied •O2 − radicals’ involvement in photodegradation. CIP mineralisation by 48.53% over 3 h under sunlight was observed. After undergoing four cycles of sunlight exposure, the degradation efficiency reached 84.89%. Additionally, during 80 min of UV-C irradiation, the photodegradation efficiency of the dyes turquoise blue and Congo red was 77.91% and 98.92%, respectively.