Synthesis of bismuth vanadate by laser ablation in liquid route and its structural and optical characterization

In this work, a bottom up route was developed to obtain BiVO 4 by dissociation of precursors by laser ablation. The process consisted of using a laser beam focusing on a mixture of bismuth oxide in an ammonium metavanadate solution under agitation. The precipitate obtained demonstrated high crystallinity as evidenced by the narrow peaks in the x-ray diffraction pattern and 20 nm crystallite size calculated by the Scherrer equation, approximately, and the presence of monoclinic Scheelite and tetragonal zirconia-like phases mixing. Particles showed a certain degree of agglomeration with size ranging from 400-200 nm according to SEM images. The Raman spectra showed the typical vibrational modes of mixed phases, which only changed into monoclinic scheelite after being calcined at 500 °C. The band gap was determined using Tauc plot and revealed a 2.5 eV energy band gap with a well-defined band in the visible range of spectrum for monoclinic phase samples material thermally treated. Photoluminescence results demonstrated low recombination rate for electron-hole pair indicating could be suitable in photocatalysis.