An investigation on photocatalytic activities of rare earth doped ZnO nanoparticles for degradation of Rhodamine B dye

Abstract

The scientific interest in photocatalysis using semiconductors has increased exponentially in newlinerecent years due to its intriguing advantages over other waste water treatment methods. Since newlinephotocatalysis mainly depends on the photo-induced charge carriers, therefore, the successful newlineseparation of these electron-hole pairs is paramount for attaining photocatalytic reactions. newlinePhotocatalysis using zinc oxide (ZnO) as catalyst is one of the most promising, economical newlineand ecofriendly oxidation process as ZnO is cheap, non-toxic, biochemically stable. newlineHowever, due to narrow spectral response range, ZnO absorbs light predominantly in the newlineultraviolet (UV) region i.e. wavelength (and#955;) between 200 nm to 400 nm, which limits its newlineutilization of visible spectrum. Various literature precedents are available on monovalent rare newlineearth dopings in ZnO, which indicate that such dopings increase the efficiency of newlinephotocataysis under UV irradiation. Literature study also suggests a slight shift towards newlinevisible region in absorption wavelength of ZnO on rare earth dopings. Limited literature newlineprecedents are available on study of divalent and trivalent rare earth dopings in ZnO under newlinevisible irradiation. In the current work, divalent and trivalent rare earth ion dopings were newlineincorporated into the matrix of ZnO nanoparticles to modify the bandgap of ZnO for effective newlinecharge separation between electron-hole pairs which results in effective utilization of solar newlinelight. Modified ZnO nanoparticles were examined for photocatalytic degradation of test newlinepollutant Rhodamine B dye, for their effective use in waste water treatment. Several newlinetechniques were utilized for characterization of the pure and doped ZnO samples. Varying newlineconcentrations of dopants in ZnO which consisted of lanthanum, cerium (La, Ce) (0.00-0.04 newlineM), cerium, dysprosium (Ce, Dy) (0.00-0.05 M) and lanthanum, cerium, dysprosium (La, Ce, newlineDy) (0.00-0.05 M), were synthesized using low cost and simple co-precipitation technique. newlinevii newlineThe synthesized rare earth doped ZnO nano