Mechanochemically synthesized m-BiVO₄ nanoparticles for visible light photocatalysis

In this work, a mechanochemical high energy ball milling approach was used to synthesize monoclinic BiVO₄ (m-BiVO₄) nanoparticles in an attempt to simultaneously reduce the particle size and improve the throughput for practical photocatalytic applications. The effect of annealing to eliminate the induced defects and thus enhance the reactivity was studied on the mechanochemically synthesized BiVO₄ nanoparticles. Besides using the conventional characterization tools of XRD, Raman, FE-SEM, HRTEM, XPS and UV-vis diffuse reflectance to examine the crystalline structure, morphology, chemical states and visible light absorption, a customized Kelvin probe coupled with an LED light source was developed as a non-contact tool to study the surface photovoltage (SPV) response for understanding charge generation and separation. The photocatalytic performance was finally evaluated for the degradation of Rhodamine B (RhB) under visible light irradiation to correlate with these physicochemical properties.