2, Aligarh Muslim University, Aligarh, , India
The degradation of organic pollutants in the aqueous environment by using semiconductor photocatalyst has become an attractive process. Photocatalysis as a green, feasible and sustainable technology has received growing attention owing to its potential to solve energy and environmental problems. Currently, the major focus in photocatalysis is the design and development of highly efficient and low-cost photocatalysts. Therefore, various semiconductor metal oxide has been designed and developed for the efficient removal of organic pollutants from wastewater. As a robust semiconductor ZnO has been widely used for wastewater treatment due to its charge carrier generation upon excitation by light and reactive oxygen species formation in aqueous suspension. However, fast recombination of massive charge carrier and low solar energy conversion efficiency limits their large scale applications. Therefore, design of visible light responsive photocatalyst is of great concern from commercial point of view. Herein, we report the strategy for the suppression of electron−hole pair recombination rate, extended the absorption edge in the visible region and enhanced the photocatalytic efficiency by introducing rare earth metal as dopant. The doping of rare earth metals is an effective way for enhancing photocatalytic performance of a semiconductor under visible light irradiation. Such modifications not only reduced massive charge carrier also serving for harvesting of visible light. The photocatalytic activity of undoped and Er-doped ZnO nanoparticles (NPs) was investigated by studying the degradation of two different organic dyes as a function of irradiation time. The results indicate that the photocatalytic activity of doped ZnO was found to be higher than undoped ZnO for degradation of dyes. The enhanced photocatalytic activity of Nd-doped ZnO can be ascribed predominantly due to their improved visible light absorption property and decrease in the recombination rate by the efficient charge separation of photoinduced electron−hole pair as inferred from PL spectra efficient. Our present work provides a facile, green and new pathway for the design of ZnO-based photocatalysts with good morphology that respond both UV and visible light and promotes their practical application in various environmental remediation.