Study on the effective removal of NO by light-driven N-BiOCl

In this paper, an N -doped BiOCl photocatalyst was prepared and systematically characterized. The results showed that N doping does not change the crystal phase of BiOCl but changes the surface morphology of BiOCl nanosheets and increases specific surface area. N -doped BiOCl broadens the light absorption region, narrows the band gap and promotes the separation of the photoexcited carriers. N could be adsorbed on the Bi or to replace Cl atom in the BiOCl lattice, causing the generation of intermediate energy levels in the band gap of N -BiOCl including N 2p-Cl 2p hybrid states, N 2p-O 2p hybrid states or N 2p state. N -BiOCl achieves about 60% removal efficiency of NO under all-light irradiation and exhibits favorable stability and recyclability. The presence of some H 2 O in the reaction system promotes the photodegradation of NO, while O 2 greatly affects the efficiency of NO removal. Moreover, N doping promotes the formation of •O 2 − and •OH on N -BiOCl photocatalyst under all-light irradiation, resulting in the enhancement of photocatalytic oxidation of NO to NO 3 – . NO could be adsorbed on the surface of N -BiOCl or oxidized into NO 2 – under darkness and further oxidized into NO 3 – under all-light irradiation. However, the accumulation of the final product on the catalyst surface results in a decrease in photoactivity.