The effect of pH on the photocatalytic performance of BiVO4 for phenol mine sewage degradation under visible light

The morphology of BiVO4 was successfully controlled via adjusting pH values by an ethylene glycol solvent method to degrade phenol mine sewage. The as-prepared samples were characterized by XRD, SEM, XPS, UV-vis and PL, respectively. It was indicated that, initial pH values play an important role on the morphology of BiVO4. The results illustrated that the photocatalytic activities of the BiVO4 towards phenol degradation was improved with the increasing of pH values. The sample prepared at pH being 11 exhibited the highest photocatalytic degradation of phenol, being about 95.6% in 5 h visible light irradiation. The improvement of photocatalytic activity mainly is due to the changed morphology, higher light absorption ability, narrower band gap and lower recombination ratio of photo-induced electron-hole pairs. The radical species responsible for degradation of phenol were also performed and the main radical species are O-center dot(2)- and (OH)-O-center dot.