Er-Doped BiVO/BiFeO Nanocomposites Synthesized via Sonochemical Process and Their Piezo-Photocatalytic Application.

In this work, Er-doped BiVO/BiFeO composites are prepared using the sonochemical process with a difference of rare earth loading compositions. The crystallinity and chemical and morphological structure of as-synthesized samples were investigated via X-ray diffraction, Raman scattering, and electron microscopy, respectively. The diffuse reflectance technique was used to extract the optical property and calculate the optical band gap of the composite sample. The piezo-photocatalytic performance was evaluated according to the decomposition of a Rhodamine B organic compound. The decomposition of the organic compound was achieved under ultrasonic bath irradiation combined with light exposure. The Er-doped BiVO/BiFeO composite heterojunction material exhibited significant enhancement of the piezo-photocatalytic activity under both ultrasonic and light irradiation due to the improvement in charge generation and separation. The result indicates that Er dopant strongly affects the phase transformation, change in morphology, and alternation in optical band gap of the BiVO matrix. The incorporation of BiFeO in the composite form with BiVO doped with 1%Er can improve the photocatalytic performance of BiVO via piezo-induced charge separation and charge recombination retardment.