Density functional theory study on a nitrogen-rich carbon nitride material C3N5 as photocatalyst for CO2 reduction to C1 and C2 products

Yuelin Wang; Thanh Ngoc Pham; Yu Tian; Yoshitada Morikawa; Likai Yan

doi:10.1016/j.jcis.2020.10.054

Density functional theory study on a nitrogen-rich carbon nitride material C₃N₅ as photocatalyst for CO₂ reduction to C1 and C2 products

J Colloid Interface Sci. 2021 Mar:585:740-749. doi: 10.1016/j.jcis.2020.10.054. Epub 2020 Oct 21.

Authors

Yuelin Wang¹, Thanh Ngoc Pham², Yu Tian³, Yoshitada Morikawa⁴, Likai Yan⁵

Affiliations

¹ Institute of Functional Material Chemistry, Key Laboratory of Polyoxometalate Science of Ministry of Education, Faculty of Chemistry, Northeast Normal University, Changchun 130024, PR China; Department of Precision Engineering, Graduate School of Engineering, Osaka University, 2-1, Yamada-oka, Suita, Osaka 565-0871, Japan.
² Department of Precision Engineering, Graduate School of Engineering, Osaka University, 2-1, Yamada-oka, Suita, Osaka 565-0871, Japan.
³ Institute of Functional Material Chemistry, Key Laboratory of Polyoxometalate Science of Ministry of Education, Faculty of Chemistry, Northeast Normal University, Changchun 130024, PR China.
⁴ Department of Precision Engineering, Graduate School of Engineering, Osaka University, 2-1, Yamada-oka, Suita, Osaka 565-0871, Japan; Elements Strategy Initiative for Catalysts and Batteries (ESICB), Kyoto University, Goryo-Ohara, Nishikyo-ku, Kyoto 615-8245, Japan; Research Center for Ultra-Precision Science and Technology, Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita 565-0871, Osaka, Japan. Electronic address: morikawa@prec.eng.osaka-u.ac.jp.
⁵ Institute of Functional Material Chemistry, Key Laboratory of Polyoxometalate Science of Ministry of Education, Faculty of Chemistry, Northeast Normal University, Changchun 130024, PR China. Electronic address: yanlk924@nenu.edu.cn.

PMID: 33183759
DOI: 10.1016/j.jcis.2020.10.054

Abstract

A new-type nitrogen-rich carbon nitride material C₃N₅ has been synthesized recently, in which the C:N ratio increases from 3:4 in g-C₃N₄ to 3:5 due to the introduction of azo linkage (NN) connecting segments in two C₆N₇ units. Herein, C₃N₅ as a photocatalyst for CO₂ reduction was investigated by density functional theory methods. The electronic and optical properties indicate that C₃N₅ has a longer visible-light region with 2.0 eV of band gap in comparison with g-C₃N₄. The spatial distributions of the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) show that the π network of C₃N₅ is extended by introducing -NN- linkage, which results in much higher photocatalytic efficiency than g-C₃N₄. The Gibbs free energies for possible CO₂ reaction paths on C₃N₅ were computed. The results show that CO₂ can be reduced to CH₄ with a low limiting potential of -0.54 V and to CH₃CH₂OH with a low limiting potential of -0.61 V, which all driven by solar energy. The present work is expected to provide useful guide for new-type nitrogen-rich C₃N₅ as promising photocatalyst for CO₂ reduction reaction (CO₂RR).

Keywords: C(3)N(5); CO(2) reduction reaction; Carbon nitride materials; Density functional theory; Metal-free materials; Photocatalyst.