Photoelectroactivity of Bismuth Vanadate Prepared by Combustion Synthesis: Effect of Different Fuels and Surfactants

Dip-coating deposition of resistive BiVO4 thin film and evaluation of their photoelectrochemical parameters under distinct sources illumination

“…The diffractogram for the film deposited on glass substrate allows identifying only peaks related to BiVO 4 phase because the substrate is an amorphous glass, whereas the film deposited on FTO substrate leads to a diffractogram where, besides the BiVO 4 peaks, the FTO diffracted peaks can be also identified. The obtained diffraction patterns are in good agreement with previously published reports, with samples either in the form of powders [23,[27][28][29], as nanocrystalline thin film [7,10,16,18], obtained by solution combustion synthesis (SCS) technique.…”

“…On the other hand, the photogenerated holes on the valence band of the BiVO 4 surface have enough lifetime, in order to create a density of holes on the surface relatively high, preventing the fast electron-hole recombination-back process. This high density of surface holes can oxidize water molecules to • OH-type radicals that are fundamental in the MB degradation process, due to the attack to the chromophore group of the molecule [7,10,27,37], as already mentioned.…”

“…The monoclinic phase of BiVO 4 was obtained by the solution combustion synthesis (SCS) technique, adapted from widely published procedures [23][24][25][26][27][28][29]. A scheme showing the experimental procedure of the BiVO 4 thin films synthesis can be seen in Fig.…”

“…Then, the pH of this solution was adjusted to 7-8 by dripping concentrated ammonium hydroxide (NH 4 OH, Sigma-Aldrich, p.a.). Finally, 1.5 g of urea is added, which plays the role of combustible for the self-sustainable reaction of the SCS technique [25][26][27]. On the other hand, as part of the synthesis process, the vanadium precursor solution was prepared by adding 1.0 g of citric acid and 0.5 g of (NH 4 ) 3 VO 4 (Sigma-Aldrich, p.a.…”

“…Numerous techniques have been employed for obtaining BiVO 4 semiconductor material [7,8,13,16,18,21,23]. Among all the available processes, the solution combustion synthesis (SCS) technique may be selected due to its simplicity and versatility for obtaining BiVO 4 nanocrystals with monoclinic structure and relatively low cost process [23][24][25][26][27][28][29]. However, as many other semiconductor oxides, the BiVO 4 obtained by this process presents a rather high electrical resistivity [30][31][32].…”