Mesoporous C-doped C3N5 as a superior photocatalyst for CO2 reduction
Aathira M. Sadanandan, Mohammed Fawaz, Nithinraj Panangattu Dharmarajan, Matej Huš, Gurwinder Singh, CI Sathish, Blaž Likozar, Zhixuan Li, Ajanya M. Ruban, Chung‐Hwan Jeon, Jae‐Hun Yang, Prashant Kumar, Ajayan Vinu
Abstract
Use of naturally abundant solar light for CO 2 reduction is a green pathway to reduce carbon footprint. C 3 N 5 is a promising visible-light photocatalyst with enhanced local electron concentration and more active N N sites compared to g-C 3 N 4 . We herein report development of mesoporous C-doped C 3 N 5 through a simple copolymerisation of 3-amino-1,2,4-triazole with trimesic acid via hard-templating method, which demonstrated enhanced light absorption ability and delocalised π-electron density (as evident from density functional theory calculation), resulting in efficient charge transfer to the active surface sites of the photocatalyst. The optimised C-doped mesoporous C 3 N 5 exhibited a superior photocatalytic CO 2 reduction activity with the CO evolution of 116.6 µmol·g −1 , which is 4-fold and 12-fold times higher than that of C 3 N 5 and g-C 3 N 4 respectively. The enhanced photocatalytic CO 2 conversion efficiency can be attributed to the synergetic effects of π-electron modulation by C-doping and enhanced surface-active sites brought by mesoporosity. • C-doped mesoporous C 3 N 5 , exhibits significantly enhanced visible-light absorption and suppresses charge recombination. • By controlling the π-electron distribution through C-doping, we have successfully manipulated the optical properties of C 3 N 5 . • The prepared novel C-doped mesoporous C 3 N 5 shows a 12 times incriment in CO 2 RR to CO, comapred to that of C 3 N 4. • Extended photostability (> 48 h) has been observed without significant loss in conversion efficiency. • Until now, C-doped mesoporous C 3 N 5 systems have not been explored for CO 2 RR.