Visible-Light-Driven Nitrogen-Doped Carbon Quantum Dots/CaTiO3 Composite Catalyst with Enhanced NO Adsorption for NO Removal

Nitrogen oxides (NOx) have attracted extensive concerns as a secondary aerosol precursor in recent years. Solar-induced photocatalytic oxidation is a promising strategy for of NOx removal nowadays. In this contribution, nitrogen-doped carbon quantum dots (N-CQDs)/CaTiO3 composite was synthesized using a facile hydrothermal process. The incorporation of N-CQDs to CaTiO3 facilitates the transfer of electrons and divorce of photogenerated carriers. NO temperature-programmed desorption (NO-TPD) demonstrated that the presence of N-CQDs was conducive to the NO adsorption in comparison with the pristine CaTiO3. The composite catalyst demonstrated much better photocatalytic performance than CaTiO3 and P25 did in regard to gaseous NO removal and NO2 selectivity under visible light irradiation. Both •O2– and •OH are believed to make a major contribution to NO removal. The role of N-CQDs was unraveled in the photocatalytic reaction of NO elimination over N-CQDs/CaTiO3 samples. This study provides insight into the co...