Porous g-C3N4 with nitrogen defects and cyano groups for excellent photocatalytic nitrogen fixation without co-catalysts

Yanjun Xue; Yichen Guo; Zhangqian Liang; Hongzhi Cui; Jian Tian

doi:10.1016/j.jcis.2019.08.067

Porous g-C₃N₄ with nitrogen defects and cyano groups for excellent photocatalytic nitrogen fixation without co-catalysts

J Colloid Interface Sci. 2019 Nov 15:556:206-213. doi: 10.1016/j.jcis.2019.08.067. Epub 2019 Aug 19.

Authors

Yanjun Xue¹, Yichen Guo¹, Zhangqian Liang¹, Hongzhi Cui¹, Jian Tian²

Affiliations

¹ School of Materials Science and Engineering, Shandong University of Science and Technology, Qingdao 266590, China.
² School of Materials Science and Engineering, Shandong University of Science and Technology, Qingdao 266590, China. Electronic address: jiantian@sdust.edu.cn.

PMID: 31446334
DOI: 10.1016/j.jcis.2019.08.067

Abstract

The porous g-C₃N₄ with nitrogen defects and cyano groups (NC-g-C₃N₄) is prepared via an alkali-assisted heat treatment of urea. Alkali can break hydrogen bonds, which accelerate thermal polymerization of urea and formation of nitrogen defects/cyano groups. The presence of nitrogen defects extends the absorption of visible light to longer wavelengths region. The cyano groups can trap g-C₃N₄'s photoinduced electrons and therefore suppress charge recombination. The formation of porous structure increases the surface area and exposes more active sites. As a consequence, compared to pure g-C₃N₄, NC-g-C₃N₄ shows boosted visible photocatalytic nitrogen fixation activity (1.59 mmol h^-1 g^-1) without co-catalysts.

Keywords: Cyano groups; Nitrogen vacancies; Photocatalytic nitrogen fixation; Porous structure; g-C(3)N(4).