Defects and internal electric fields synergistically optimized g-C 3 N 4-x /BiOCl/WO 2.92 heterojunction for photocatalytic NO deep oxidation

In this work, g-C N /BiOCl/WO heterojunction with "N-O" vacancies was prepared using NaBiO and WCl as raw materials and non-metal plasma of WO grew in-situ on the surface of BiOCl, resulting in the enhanced photocatalytic NO deep oxidation. XPS tests and DFT calculation indicated the formation of internal electric fields from g-C N to BiOCl, BiOCl to WO , which induced the transition from Ⅱ-Ⅱ-type to double Z-scheme hetero-structure. High separation efficiency, prolong lifetime and strong redox ability of photo-generated electron-hole pairs were simultaneously achieved due to the charge capture effect of defects and double Z-scheme mechanism. Therefore, g-C N /BiOCl/WO exhibited the significantly increased NO removal rates from 21.17% (BiOCl/WO ) and 36.52% (g-C N ) to 68.70% and the main oxidation product of NO was NO . This study revealed that the carrier dynamics of heterojunction photocatalysts could be optimized by the synergistic effect of defects and internal electric fields to achieve photocatalytic NO deep oxidization.