TY - JOUR

T1 - Ultrathin defective heterojunction for visible light NO removal

T2 - correlation between microstructure and reaction mechanisms

AU - Hailili, Reshalaiti

AU - Li, Zelong

AU - Lu, Xu

AU - Sheng, Hua

AU - Bahnemann, Detlef W.

AU - Zhao, Jincai

N1 - Publisher Copyright: © 2024 The Royal Society of Chemistry.

PY - 2024

Y1 - 2024

N2 - Successful integration of defective heterojunctions is a proven effective strategy for promoting carrier separations and strengthening surface-interface redox reactions. Dipole moment variations are beneficial for charge carrier separation due to enlarged polarizations, especially within defective ones. Herein, motivated by the dipole variations in BiVO4 and the unique layered structure of BiOCl, defective BiVO4/BiOCl heterojunctions were designed and integrated. The as-integrated samples displayed unique nanosheets with thicknesses decreasing from 7.24 to 2.77 nm, resulting in the simultaneous formation of stable surface defects. The heterojunctions were investigated for the removal of dilute NO (∼ppb) under visible light and exhibited 1.85- and 2.05-folds enhanced efficiencies (75%), synchronous inhibition of NO2 (16.7% selectivity) and a more positive DeNOx index (0.36) than their constituent monomers. The improved activities and stabilities of surface defects were further examined by multi-run NO removal and EPR. The NO conversion products were validated by in situ DRIFTS investigation, which showed remarkable NO oxidation into NO3− and synchronous NO2 inhibition in thinner defective BiVO4/BiOCl. Mechanistic investigations indicated that surface defects in heterojunctions not only contributed to the improved light absorption and massive production of active species by coupling suitable band alignments, prolonging the carrier lifetime (3.55 ns to 7.52 ns) but also facilitated strong interfacial electric field contact at the junction interface of monomers, which enabled the construction of a direct Z-scheme charge transfer mechanism for NO removal.

AB - Successful integration of defective heterojunctions is a proven effective strategy for promoting carrier separations and strengthening surface-interface redox reactions. Dipole moment variations are beneficial for charge carrier separation due to enlarged polarizations, especially within defective ones. Herein, motivated by the dipole variations in BiVO4 and the unique layered structure of BiOCl, defective BiVO4/BiOCl heterojunctions were designed and integrated. The as-integrated samples displayed unique nanosheets with thicknesses decreasing from 7.24 to 2.77 nm, resulting in the simultaneous formation of stable surface defects. The heterojunctions were investigated for the removal of dilute NO (∼ppb) under visible light and exhibited 1.85- and 2.05-folds enhanced efficiencies (75%), synchronous inhibition of NO2 (16.7% selectivity) and a more positive DeNOx index (0.36) than their constituent monomers. The improved activities and stabilities of surface defects were further examined by multi-run NO removal and EPR. The NO conversion products were validated by in situ DRIFTS investigation, which showed remarkable NO oxidation into NO3− and synchronous NO2 inhibition in thinner defective BiVO4/BiOCl. Mechanistic investigations indicated that surface defects in heterojunctions not only contributed to the improved light absorption and massive production of active species by coupling suitable band alignments, prolonging the carrier lifetime (3.55 ns to 7.52 ns) but also facilitated strong interfacial electric field contact at the junction interface of monomers, which enabled the construction of a direct Z-scheme charge transfer mechanism for NO removal.

UR - http://www.scopus.com/inward/record.url?scp=85198983815&partnerID=8YFLogxK

U2 - 10.1039/d4en00362d

DO - 10.1039/d4en00362d

M3 - Article

AN - SCOPUS:85198983815

VL - 11

SP - 3301

EP - 3316

JO - Environmental science: Nano

JF - Environmental science: Nano

SN - 2051-8153

IS - 8

ER -