Pt-Ag/Ag3PO4-WO3 nanocomposites for photocatalytic H2 production from bioethanol

Crystalline Ag3PO4 and WO3 nanofibers were synthesized by microwave and electrospinning methods. Three different WO3 nanofibers composition (5, 10 and 15 wt%) were used to obtain Ag3PO4/WO3 nanocomposite heterostructures, which are effective visible light active photo catalysts. Further, a simple, enviro-friendly, and cost-effective biogenic synthesis method have been achieved using Salvia officinalis extract to decorate Pt-Ag metal nanoparticles on the surface of Ag3PO4-WO3 composites. Presence of bioactive agents in the extract are responsible for the Pt and Ag3PO4 reduction to obtain Pt-Ag/Ag3PO4-WO3 nanocomposites and for prevention of the Pt nanoparticles from aggregation in aqueous medium. Various analytical techniques such as XRD, SEM, FTIR, DR UV-vis, XPS and N2 gas physisorption were utilized to characterize the synthesized photocatalysts. The band gap energy values were decreased after decoration of Pt and Ag metal nanoparticles over Ag3PO4-WO3 nanocomposites. The Pt and Ag metal nanoparticles decorated Ag3PO4-WO3 (10 wt%) nanocomposite exhibited highest photo catalytic activity for H2 production from bioethanol due to possession of unique physicochemical properties low band gap and surface area. In addition, presence of plasmonic nanoparticles assisted for the efficient electron trap to decrease the e--h+ recombination rate to enhance the hydrogen production.