Strengthening reactive metal-support interaction to stabilize high-density Pt single atoms on electron-deficient g-C3N4 for boosting photocatalytic H2 production

Tuning reactive metal-support interaction (RMSI) is a promising approach to optimizing catalytic active sites via the electronic, geometric and compositional effects. In general, the RMSI is conducted on the reducible oxides via a high-temperature reaction ( > 550 degrees C). Herein we report a strong RMSI between N single atom (NSA) and nonoxide-based g-C3N4 built by an in-situ photocatalytic reduction method at a sub-zero temperature. The experimental observation confirms that the rich N vacancies in g-C(3)N(4)4 produce an obvious electron-deficient effect, which greatly enhances the RMSI. This strong RMSI contributes to the highest NSA coverage density of 0.35 mg m(-2) reported to date in carbon-based materials and outstanding H-2-evolution activity of 174.5 mmol g(-1)h(-1) per NSA relative to those on the electron-rich g-C3N4. The structure simulation reveals that the RMSI can not only stabilize the NSA on the electron-deficient g-C3N4 via the strong chemical bond between NSA and the two-coordinated C (C-2C) sites caused by the N vacancies, but also promises the NSA with an optimized electronic and geometric structures for capturing photogenerated electrons and producing H-2. This finding opens a new channel for designing and manipulating single atom-loaded photocatalyst via the RMSI at a sub-zero low temperature.