Preparation of Gray ZnO 1-x Photocatalyst Containing Oxygen Vacancies for the Highly Efficient Removal of Nitric Oxide and Acetaminophen

Abstract

“defect engineering” has been consiered as an effective strategy to improve its photocatalytic activity. ZnO_1 − x photocatalysts containing oxygen defects were prepared by “oxygen-atom capture” method in different lithium-naphthalene solution. The effect of concentration of lithium-naphthalene solution on the oxygen vacancies and photocatalytic performance of ZnO were researched comprehensively. The results indicate that ZnO photocatalysts treated in lithium-naphthalene solution show disordered structure on the material due to the presence of oxygen vacancies. Compared with W-ZnO, ZnO_1 − x exhibit higher visible light absorption and enhanced photocatalytic properties. Moreover, more oxygen vacancies are introduced into ZnO−0.8, which reduce its bandgap to 3.04 eV and improve the separation efficiency and transfer speed of photo-generated carriers. Therefore, the efficiency of NO removal by ZnO−0.8 is enhanced to 54.3% under ultraviolet light irradiation, and its degradation efficiency of NO is ~ 12 times greated than that of W-ZnO. Oxygen vacancies acted as capturer of electrons, inhibiting the recombination of photogenerated electrons and holes. Thus, increasing the appropriate concentration of oxygen vacancies on the surface of the material can enhance its photocatalytic activity.