STUDIES ON POLYPYRROLE MODIFIED ZnFe2O4 BASED HETEROJUNCTION FOR PHOTOCATALYTIC APPLICATIONS

Abstract

newline v newlineABSTRACT newlineTitle of the thesis: Studies on polypyrrole modified ZnFe2O4 based heterojunction newlinefor photocatalytic applications newlineElimination of environmental pollutants, production of hydrogen (H2) and newlineremoval of pathogenic bacteria from water are essential to solve increasing newlineenvironmental pollution and energy catastrophe by visible light driven photocatalysts is newlinequite demanding science in current scenario. To validate this purpose, designing of low newlinecost and durable semiconductors based photocatalysts with great light absorption newlinecapacity becomes the most challenging issue for researchers. Out of the numerous newlinenumbers of reported photocatalysts, this thesis contains iron-based metal ferrite, newlinespecifically zinc ferrite (ZnFe2O4) as parent material because of their high activity, newlinesuitable band-gap, advanced optoelectronic features, recyclability and stability in various newlineaquatic environments. The composite materials of ZnFe2O4 were characterized and newlinetested against pollutant degradation (Phenol, Levofloxacin, Gemifloxacin and newlineCiprofloxacin), Cr (VI) reduction, H2 evolution and antibacterial activities. newlineA series of promising visible light driven ZnFe2O4 modified Al2O3and#8210;MCM-41 newline(ZFAM) nanocomposites were designed by wet impregnation method by loading newlinedifferent wt % (2, 6, 10) of ZnFe2O4 on the surface of mesoporous Al2O3and#8210;MCM-41. All newlinethe prepared photocatalysts were analyzed by using XRD, SEM, N2sorption, UV-Vis newlineDRS, XPS, FTIR and HRTEM techniques to uncover and confirm the formation of newlinephase, morphology and porous structure of the prepared nanocomposites. In the photo- newlineFenton reaction, the ZnFe2O4 modified Al2O3and#8210;MCM-41 nanocomposites exhibit a newlinesignificant catalytic activity for the photo-Fenton degradation of phenol (40 min, 99 %) newlinevia photocatalysis and photocatalytic reduction of Cr (VI) (60 min, 66 %) under sunlight newlinewith an excellent reusability nature. The high photo-Fenton activity of the composites is newlinemainly attributed to mesoporosity and high surface area of support Al2O3and#8722;MCM-41, newlineproper light harvestation and increased charge transfer efficiency by active species newlineZnFe2O4, and suitable band edge potential for hydroxyl radical generation. The photo- newlineFenton activities were further supported by the high photocurrent (0.29mA