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

• The m-BiVO4 samples were synthesized via a template-free solvothermal route.
• The morphologies could be easily controlled by the simple change of the pH values.
• The pH values could affect on the preferential growth oriented along {040} facets.

Hierarchically structured m-BiVO4 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 BiVO4 oriented along {040} facets. The pinwheel-like sample with the highest relative intensities of the diffraction peaks I040/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.