Enhanced sunlight-driven photocatalytic performance of ZnO prepared with the assistance of urea

As a prospective photo catalyst, ZnO has attracted increasing scientific attentions. However, the practical application of ZnO has been significantly hampered by the fast recombination of the photo induced electron-hole charge pairs. Herein, to further ameliorate the photocatalytic property of ZnO, ZnO with enhanced sunlight-driven photocatalytic performance was prepared by a Sol-gel method with the assistance of urea. The results show that the separation rate of photo induced electron-hole charge pairs of ZnO prepared with the assistance of urea was remarkably promoted, supported by surface photo voltage spectroscopy (SPS) characterization. The enhanced separation rate of photo induced electron-hole charge pairs results in efficient formation of O-center dot(2)-, certified by nitroblue tetrazolium (NBT) experiments. The increased content of O-center dot(2)- can accelerate the decay of rhodamine B (RhB). Moreover, the presence of urea in the synthetic system increases the content of surface hydroxyl. The photocatalytic performance can be definitely benefited from all these advantageous factors. When the molar ratio of N (in urea)/Zn is 0.5%, the ZnO prepared displays the highest photocatalytic activity.