Weak-Field Electro-Flash Induced Asymmetric Catalytic Sites toward Efficient Solar Hydrogen Peroxide Production

• Published in: JACS Au Vol. 4; no. 3; pp. 1219 - 1228
• Main Authors: Chen, Fangshuai, Lv, Ximeng, Wang, Haozhen, Wen, Fan, Qu, Liangti, Zheng, Gengfeng, Han, Qing
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 25.03.2024
• Subjects: weak-field electro-flash strategy; borocarbonitride; photocatalysis; asymmetric catalytic site; hydrogen peroxide
• ISSN: 2691-3704; 2691-3704
• DOI: 10.1021/jacsau.4c00076

Borocarbonitride (BCN), in a mesoscopic asymmetric state, is regarded as a promising photocatalyst for artificial photosynthesis. However, BCN materials reported in the literature primarily consist of symmetric N-[B]3 units, which generate highly spatial coupled electron–hole pairs upon irradiation, thus kinetically suppressing the solar-to-chemical conversion efficiency. Here, we propose a facile and fast weak-field electro-flash strategy, with which structural symmetry breaking is introduced on key nitrogen sites. As-obtained double-substituted BCN (ds-BCN) possesses high-concentration asymmetric [B]2–N-C coordination, which displays a highly separated electron–hole state and broad visible-light harvesting, as well as provides electron-rich N sites for O2 affinity. Thereby, ds-BCN delivers an apparent quantum yield of 7.6% at 400 nm and a solar-to-chemical conversion efficiency of 0.3% for selective 2e-reduction of O2 to H2O2, over 4-fold higher than that of the traditional calcined BCN analogue and superior to the metal-free C3N4-based photocatalysts reported so far. The weak-field electro-flash method and as-induced catalytic site symmetry-breaking methodologically provide a new method for the fast and low-cost fabrication of efficient nonmetallic catalysts toward solar-to-chemical conversions.