Enhanced photocatalytic removal of tetracycline using Ag/AgBr embedded activated carbon with different chemical activators

Abstract

This study compares the enhanced photocatalytic properties and performance of the silver/silver bromide (Ag/AgBr) nanoparticles embedded in the activated carbon (AC) prepared from pinecone biomass activated using ZnCl2 (AB-ACPC-Z), and KOH (AB-ACPC-K), for removal of tetracycline (TC). The characterization results confirmed the incorporation of uniform dispersed Ag/AgBr (AB) species on the ACPCs with a particle size between 150 and 250 nm. A quasi-cubic morphology of AB NPs was achieved using the ACPC-Z catalyst promoter. The AB-ACPC-Z photocatalyst had a bandgap of 2.43 eV, with an improved optical absorption in the visible light, compared to that of AB-ACPC-K, and AB NPs. A lower degree of recombination of photogenerated charge carriers resulted from adding ACPC-Z to the AB NPs. AB-ACPC-Z and AB-ACPC-K exhibited high removal efficiencies of TC (89.08 % and 87.8 %), respectively at pH 7. Using central composite design (CCD), the optimum experimental parameters for photocatalytic activity in order of significance, were determined to be an initial TC concentration of 20 mg/L, a photocatalyst dosage of 0.45 g/L and an irradiation time of 120 min. LC/MS analysis revealed the influence of reactive oxidative species and ring-opening degradation pathway.