Oxygen vacancy engineering of photocatalytic nanomaterials for enrichment, activation, and efficient removal of nitrogen oxides with high selectivity: a review

Air pollution by trace levels of nitric oxide (NO) pollution is threatening human health by causing acid rain and haze pollution through photochemical reactions. Here, we review photocatalytic technologies that use oxygen vacancy engineering-mediated nanomaterials for the control of air pollutants such as NO and nitrogen dioxide. We present oxygen vacancy parameters and reactor regulation mechanisms. We explain the functions of oxygen vacancies in the adsorption and enrichment processes of NO on the photocatalyst surface. We highlight the relationship between oxygen vacancies and O2 activation in photocatalytic reactions. The mechanisms ruling selectivity in NO photodegradation, and the suppression of photocatalyst deactivation are discussed.