The pH-controlled {040} facets orientation of BiVO4 photocatalysts with different morphologies for enhanced visible light photocatalytic performance.

Hierarchically structured m -BiVO 4 samples with different morphologies have been synthesized via a template-free solvothermal route by adjusting the pH value of the precursor solution. The effects of pH value on structure, morphology and photocatalytic activity were investigated. The results showed that the pH value played a great influence not only on the formation of the hierarchical structures with different morphologies, but also on the preferential crystal growth of the BiVO 4 oriented along {040} facets. The pinwheel-like sample with the highest relative intensities of the diffraction peaks I 040 / I –121 exhibited the best photocatalytic activity for the photodegradation of MB under visible light irradiation. According to the Ostwald ripening process, a possible oriented aggregation mechanism was proposed. [ABSTRACT FROM AUTHOR]