Synthesis of novel ZnO/Geopolymer nanocomposite photocatalyst for degradation of congo red dye under visible light

Abstract

Abstract Herein, we report synthesis of a novel ZnO/Geopolymer nanocomposite photocatalyst with highly efficient photocatalytic properties under visible-light irradiation. It has been synthesized by facile hydrothermal method which includes incorporation of ZnO nano-spheres uniformly, onto mesoporous geopolymeric base material. LD (Linz-Donawitz) slag, a steel industry waste, has been geopolymerised for preparing this mesoporous support material, named as LD slag based geopolymer (LDSGP). The physical, optical and electrochemical properties of the ZnO/Geopolymer (ZnO/LDSGP) photocatalyst have been analyzed using standard characterization methods. ZnO/LDSGP nanocomposite has nano-spherial morphological structures with high crystallinity, having visible light sensitivity, with photo-current density as 0.45\xa0mA/cm2. The optical band gap reduces from 3.37 (commercial ZnO) to 2.95\xa0eV (ZnO/LDSGP). The photocatalytic properties of ZnO/LDSGP have been evaluated for degradation congo red (CR) by correlating with first-order reaction kinetics. A probable CR photo-degradation mechanism by ZnO/LDSGP, has been proposed.