Tunable CO2-to-syngas conversion via strong electronic coupling in S-scheme ZnGa2O4/g-C3N4 photocatalysts

Lang Pei; Zhenggang Luo; Xusheng Wang; Zhanfeng Ma; Yuhang Nie; Jiasong Zhong; Ding Yang; Sateesh Bandaru; Bao-Lian Su

doi:10.1016/j.jcis.2023.07.148

Tunable CO₂-to-syngas conversion via strong electronic coupling in S-scheme ZnGa₂O₄/g-C₃N₄ photocatalysts

J Colloid Interface Sci. 2023 Dec 15;652(Pt A):636-645. doi: 10.1016/j.jcis.2023.07.148. Epub 2023 Jul 25.

Authors

Lang Pei¹, Zhenggang Luo², Xusheng Wang³, Zhanfeng Ma², Yuhang Nie², Jiasong Zhong⁴, Ding Yang⁵, Sateesh Bandaru⁶, Bao-Lian Su⁷

Affiliations

¹ College of Materials and Environmental Engineering, Hangzhou Dianzi University, Hangzhou 310018, China; Key Laboratory of Surface & Interface Science of Polymer Materials of Zhejiang Province, Hangzhou 310018, China.
² College of Materials and Environmental Engineering, Hangzhou Dianzi University, Hangzhou 310018, China.
³ School of Materials Science and Engineering, Zhejiang Sci-Tech University, Hangzhou 310018, China.
⁴ College of Materials and Environmental Engineering, Hangzhou Dianzi University, Hangzhou 310018, China. Electronic address: jiasongzhong@hdu.edu.cn.
⁵ College of Materials and Environmental Engineering, Hangzhou Dianzi University, Hangzhou 310018, China. Electronic address: dingyang@hdu.edu.cn.
⁶ College of Materials and Environmental Engineering, Hangzhou Dianzi University, Hangzhou 310018, China. Electronic address: sbandaru@hdu.edu.cn.
⁷ State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, 122 Luoshi Road, 430070 Wuhan, Hubei, China; Laboratory of Inorganic Materials Chemistry (CMI), University of Namur, 61 rue de Bruxelles, B-5000 Namur, Belgium. Electronic address: bao-lian.su@unamur.be.

PMID: 37516580
DOI: 10.1016/j.jcis.2023.07.148

Abstract

The conversion of CO₂ into syngas, a mixture of CO and H₂, via photocatalytic reduction, is a promising approach towards achieving a sustainable carbon economy. However, the evolution of highly adjustable syngas, particularly without the use of sacrifice reagents or additional cocatalysts, remains a significant challenge. In this study, a step-scheme (S-scheme) 0D ZnGa₂O₄ nanodots (∼7 nm) rooted g-C₃N₄ nanosheets (denoted as ZnGa₂O₄/C₃N₄) heterojunction photocatalyst was synthesized vis a facial in-situ growth strategy for efficient CO₂-to-syngas conversion. Both experimental and theoretical studies have demonstrated that the polymeric nature of g-C₃N₄ and highly distributed ZnGa₂O₄ nanodots synergistically contribute to a strong interaction between metal oxide and C₃N₄ support. Furthermore, the desirable S-scheme heterojunction in ZnGa₂O₄/C₃N₄ efficiently promotes charge separation, enabling strong photoredox ability. As a result, the S-scheme ZnGa₂O₄/C₃N₄ exhibited remarkable activity and selectivity in photochemical conversion of CO₂ into syngas, with a syngas production rate of up to 103.3 μ mol g^-1 h^-1, even in the absence of sacrificial agents and cocatalyst. Impressively, the CO/H₂ ratio of syngas can be tunable within a wide range from 1:4 to 2:1. This work exemplifies the effectiveness of a meticulously designed S-scheme heterojunction photocatalyst for CO₂-to-syngas conversion with adjustable composition, thus paving the way for new possibilities in sustainable energy conversion and utilization.

Keywords: C(3)N(4); CO(2) reduction; S-scheme; Syngas; ZnGa(2)O(4).