Surface decoration of plasmonic Ag nanospheres for enhanced visible light photocatalysis of BiVO4

Abstract

The industrial concern of producing benzaldehyde (BD) more efficiently is the key aspect of this work. Therefore, the oxidation of benzyl alcohol (BA) by photocatalytic route was chosen. The amoeba-like BiVO4 (BV) particles were synthesized by co-precipitate method since it gives higher yield when compared to other methods and silver nanoparticles were decorated over its surface by photo deposition method. Due to surface plasmon resonance (SPR effect), the decorated samples showed enhanced optoelectronic properties. The band edge positions shifted to higher energy levels profitably paving the way for the production of superoxide radicals (•O2−) effectively. The optimal catalyst material was engineered in such a way that it would facilitate the production of both •O2− and BA* radicals and inhibits the production of BD* radical. The decorated silver nanoparticles aided in increasing the surface area and the number of catalytic active sites, therein a 4.7-fold increase in benzaldehyde yield was achieved when compared to pure BV. Since monoclinic BV possesses piezoelectric property, the use of ultrasound in the reaction medium boosted the efficiency of the reaction and henceforth a maximum conversion of 88.29 % was obtained. Hydrogen peroxide formed as a byproduct, adds commercial value to this reaction.