High-yield and crystalline graphitic carbon nitride photocatalyst: One-step sodium acetate-mediated synthesis and improved hydrogen-evolution performance

Xinhe Wu; Haiqin Ma; Kai Wang; Juan Wang; Guohong Wang; Huogen Yu

doi:10.1016/j.jcis.2022.11.143

High-yield and crystalline graphitic carbon nitride photocatalyst: One-step sodium acetate-mediated synthesis and improved hydrogen-evolution performance

J Colloid Interface Sci. 2023 Mar:633:817-827. doi: 10.1016/j.jcis.2022.11.143. Epub 2022 Dec 2.

Authors

Xinhe Wu¹, Haiqin Ma², Kai Wang², Juan Wang², Guohong Wang², Huogen Yu³

Affiliations

¹ Hubei Key Laboratory of Pollutant Analysis and Reuse Technology, College of Chemistry and Chemical Engineering, Hubei Normal University, Huangshi 435002, PR China. Electronic address: wuxinhe@hbnu.edu.cn.
² Hubei Key Laboratory of Pollutant Analysis and Reuse Technology, College of Chemistry and Chemical Engineering, Hubei Normal University, Huangshi 435002, PR China.
³ Laboratory of Solar Fuel, Faculty of Materials Science and Chemistry, China University of Geosciences, Wuhan 430074, PR China. Electronic address: huogenyu@163.com.

PMID: 36493746
DOI: 10.1016/j.jcis.2022.11.143

Abstract

To avoid the drawbacks (such as multi-step operations and causing big quality loss) of currently reported molten salt-assisted strategy for the preparation of crystalline graphitic carbon nitride (g-C₃N₄) photocatalysts, in this study, an innovative and one-step sodium acetate (CH₃COONa)-mediated synthesis strategy has been designed to synthesize a high-yield and crystalline g-C₃N₄ photocatalyst. It is found that CH₃COONa can strongly combine with dicyandiamide (DCDA) to availably prevent the massive sublimation of DCDA and the following intermediates, causing the high-efficiency transformation of DCDA into g-C₃N₄ with a high yield (52.2 wt%). In addition to the promoted denitrification and quick polymerization of DCDA via CH₃COONa, the produced Na₂CO₃ from CH₃COONa decomposition at a higher temperature can further accelerate the polymerization reaction of 3-s-triazine units, leading to the final production of highly ordered and crystalline g-C₃N₄. Consequently, the resultant high-yield and crystalline g-C₃N₄ shows an obviously strengthened hydrogen (H₂)-evolution rate, about 2.4 times higher than that of bulk g-C₃N₄, which is due to the synergetic function of highly crystalline structure, reduced band gap and cyano-groups. The current one-step CH₃COONa-mediated synthesis strategy may open a novel horizon for the facile preparations and various applications of crystalline g-C₃N₄ materials.

Keywords: Crystalline; H(2) evolution; High yield; Photocatalysis; g-C(3)N(4).