Vanadium doped barium germanate microrods and photocatalytic properties under solar light

• Vanadium doped barium germanate microrods have been synthesized by the hydrothermal process.
• The band gap of vanadium doped barium germanate microrods depends on the vanadium content.
• Vanadium doped barium germanate microrods show enhanced photocatalytic activity for methylene blue under solar light.

Vanadium doped barium germanate microrods have been prepared by a facile hydrothermal process. The obtained vanadium doped barium germanate microrods are proved to be hexagonal BaGe4O9 and orthorhombic Ba2V2O7 phases by X-ray diffraction. Scanning electron microscopy shows that the vanadium doped barium germanate products consist of microrods with the diameter of microscale size. The diameter of the mirorods decreases from 800 nm to 150 nm with the vanadium doping mass percentage increasing from 1% to 10%. Solid UV–vis diffuse reflectance spectra show that the band gap of the vanadium doped barium germanate is smaller than that of the undoped barium germanate. The photocatalytic activity has been greatly enhanced by the vanadium doping. The vanadium doped barium germanate microrods exhibit great application potential for the photocatalytic degradation of methylene blue under solar light irradiation.