Molecular-level insights on NIR-driven photocatalytic H2 generation with ultrathin porous S-doped g-C3N4 nanosheets

• Published in: Applied catalysis. B, Environmental Environmental, 2023-05, Vol.325, p.122292, Article 122292
• Main Authors: Wu, Xiaojie, Li, Di, Luo, Bifu, Chen, Biyi, Huang, Yuanyong, Yu, Tingting, Shen, Nanjun, Li, Longhua, Shi, Weidong
• Format: Article
• Language: English
• Subjects: Carbon nitride nanosheets; Intermediate band gap; Near infrared driven photocatalytic; Sulfur doping; Ultrathin porous
• ISSN: 0926-3373; 1873-3883
• DOI: 10.1016/j.apcatb.2022.122292

Unraveling how mid-gap state energy level of graphitic carbon nitride (g-C3N4) promote near-infrared (NIR) driven photochemical energy conversion at the molecular level remains a grand challenge. Here, we report a series of S double-site-doped ultrathin g-C3N4 nanosheets (SUCN) with adjustable intermediate band gap benefits from light response over NIR region. The SUCN produced after optimizing S double-site doping can effectively generate hydrogen (H2) under NIR-light irradiation. The highest H2 generation rate achieved was respectively 9.35 and 17.46 μmol g−1 h−1 under λ = 765 and λ > 800 nm, which is firstly expended photocatalytic activity of S-doped g-C3N4 to NIR region beyond λ > 765 nm. We proposed a molecular-level method, i.e., the localized oxidation state of proton acceptor triethanolamine (TEOA) in the mid-gap state to ensure the NIR-driven H2 generating behavior. [Display omitted] •g-C3N4 was doped with S atoms at a specific site of the triazine skeleton.•S doping provides an adjustable intermediate band gap of g-C3N4.•The 0.36-SUCN obtained 43 times higher PHE than g-C3N4.•The S-doped g-C3N4 firstly realized PHE in the near-infrared region.•The NIR-driven H2 generation was firstly demonstrated by a molecular-level method.