@article{Wen2026, 
author = {Dongxiao Wen and Jiahe Peng and Chongbei Wu and Xiaoyi Jiang and Weiping Gong and Jizhou Jiang},
title = {Nitrogen/oxygen dual-defects modified g-C3N4 nanosheets for boosting photocatalytic CO2 reduction},
year = {2026},
journal = {Nano Research},
volume = {19},
number = {1},
pages = {94907945},
keywords = {photocatalysis, CO2 reduction, graphitic carbon nitride (g-C3N4) nanosheets, defects},
url = {https://www.sciopen.com/article/10.26599/NR.2025.94907945},
doi = {10.26599/NR.2025.94907945},
abstract = {While thermal air exfoliation is widely used to prepare graphitic carbon nitride (g-C3N4) nanosheets, the effects of calcination conditions and atmosphere on their electronic structure and photocatalytic CO2 reduction reaction (CO2RR) performance remain systematically unexplored. We prepared g-C3N4 nanosheets with varying thickness and defects by controlling exfoliation parameters. The obtained nanosheets calcined longest in air exhibited highest CO2RR activity, twice that of bulk g-C3N4. The comprehensive analysis of structural characterizations indicates the thickness of g-C3N4 nanosheets became thinner, and the defects increased as the calcination time increased. The N vacancies (Nv) and O-doping caused by N2 and O2 from air, respectively, enable valence band elevation (Nv) and conduction band depression (O-doping) that collectively redistribute the electronic structure. Nitrogen/oxygen dual-defects generated impurity levels, reduced the work function and band gap of g-C3N4 nanosheets, and served as shallow traps for photogenerated e−. The results of in-situ spectroscopy indicate these increased effective e− are enriched around of N atoms to react with the adsorbed CO2. During the CO2 reduction process, the Nv promoted the formation of *COOH, and this dual-defect co-promoted the *CO desorption, resulting in the improved CO2RR activity. These results comprehensively analyze the regulatory effect of thermal air calcination on the electronic structure of g-C3N4, providing valuable insights for designing g-C3N4 nanosheets based photocatalysts for CO2RR.}
}