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

Unraveling how mid-gap state energy level of graphitic carbon nitride (g-C 3 N 4) 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-C 3 N 4 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 (H 2) under NIR-light irradiation. The highest H 2 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-C 3 N 4 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 H 2 generating behavior. [Display omitted] • g-C 3 N 4 was doped with S atoms at a specific site of the triazine skeleton. • S doping provides an adjustable intermediate band gap of g-C 3 N 4. • The 0.36-SUCN obtained 43 times higher PHE than g-C 3 N 4. • The S-doped g-C 3 N 4 firstly realized PHE in the near-infrared region. • The NIR-driven H 2 generation was firstly demonstrated by a molecular-level method. [ABSTRACT FROM AUTHOR]