Activity and selectivity of N2 fixation on B doped g-C9N10: a density functional theory study. Issue 32 (3rd August 2022)

• Record Type: Journal Article
• Authors: Wang, Yuelin; Pham, Thanh Ngoc; Yan, Likai; Morikawa, Yoshitada
• Is Part Of: Journal of materials chemistry. Volume 10:Issue 32(2022)
• Page Start: 11791
• Page End: 11800
• Publication Date: 2022-08-03
• Subjects: Materials -- Periodicals; Chemistry, Analytic -- Periodicals; Optical materials -- Research -- Periodicals; Electronics -- Materials -- Research -- Periodicals; 543.0284
• DOI: 10.1039/d2tc02041f
• Languages: English
• ISSNs: 2050-7526

Abstract

Abstract : BN1 doped g-C9 N10 exhibits superior N2 RR activity and selectivity due to the lower U L of the N2 RR and weaker H adsorption. Abstract : N2 fixation driven by photocatalysis or electrocatalysis to produce ammonia under mild conditions is a promising method to replace the industrial Haber–Bosch process. Inspired by recent studies, which showed that the boron atom can effectively activate N2 due to its Lewis-acid characteristics, we herein investigate the mechanism of N2 adsorption and fixation on B doped g-C9 N10, a new carbon nitride material, with three different doping configurations, namely substitutions of B at C (BC1 ) and N (BN1 ) sites and B anchored g-C9 N10 (BA ) by density functional theory calculations. We found that the nitrogen reduction reaction (N2 RR) can only proceed on BN1 and BA due to N2 chemisorption ability. The optimal N2 RR mechanism of the BN1 and BA doped g-C9 N10 is the mix I mechanism with mix I low limiting potential of −0.62 V and −0.44 V, respectively. However, the H poisoning effect at BA doped g-C9 N10 due to stronger H adsorption than N2 adsorption will suppress N2 RR selectivity. In contrast, H poisoning at BN1 doped g-C9 N10 can be effectively inhibited due to weaker H adsorption ability, thereby improving the selectivity for the N2 RR. The electronic structure analysis indicates that the H–B interaction arises from hybridization between B 2py and H 1s orbitals, which is suppressed in the case of BN1 because the 2py orbital of is less populated BN1 . Our work provides useful guidance for more experimental works to explore more B doped carbon nitride materials for the N2 fixation field.