The present invention combines the advantages of fabrication of semiconductor heterostructure (Ag3PO4—WO3) with plasmonic metals (Pt and Ag) with optical interference to optimize the visible light photo response of plasmonic metals deposited semiconductor (Pt—Ag/Ag3PO4—WO3) for visible light assisted H2 generation utilizing the aqueous bio-alcohols. 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 and 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 and for prevention of the Pt nanoparticles from aggregation in aqueous medium.