New insight into enhanced photocatalytic selectivity of g-C3N4 by nitrogen vacancy introduction: Experimental study and theoretical calculation

Li Xueyan; Wang Guanlong; Lan Chenrui; Dong Xiaoli; Zhang Xiufang

doi:10.1016/j.envres.2022.113390

New insight into enhanced photocatalytic selectivity of g-C₃N₄ by nitrogen vacancy introduction: Experimental study and theoretical calculation

Environ Res. 2022 Sep;212(Pt C):113390. doi: 10.1016/j.envres.2022.113390. Epub 2022 May 5.

Authors

Li Xueyan¹, Wang Guanlong², Lan Chenrui¹, Dong Xiaoli¹, Zhang Xiufang³

Affiliations

¹ School of Light Industry and Chemical Engineering, Dalian Polytechnic University, Dalian, 116034, China.
² School of Light Industry and Chemical Engineering, Dalian Polytechnic University, Dalian, 116034, China. Electronic address: wanggl@dlpu.edu.cn.
³ School of Light Industry and Chemical Engineering, Dalian Polytechnic University, Dalian, 116034, China. Electronic address: zhangxf@dlpu.edu.cn.

PMID: 35525289
DOI: 10.1016/j.envres.2022.113390

Abstract

Constructing photocatalyst with both high efficiency and selectivity is highly desired in water treatment process. However, it is difficult to realize the selectivity of photocatalysis due to the non-selective oxidative species produced in this process. Herein, for the first time, the photocatalytic selectivity was achieved on g-C₃N₄ (CN) through N vacancy introduction for effective removal of organic pollutants, and the mechanism of vacancy induced selectivity enhancement was studied. The nitrogen vacancy modified CN (VCN) showed enhanced photocatalytic activity and unique selectivity towards phenolic compounds with electron-donating group, whose kinetic constant for p-aminophenol (p-NH₂) degradation was 5.95 times higher than that over CN. Moreover, VCN photocatalytic system also displayed similar selectivity in binary pollutant systems. Characteristics and theoretical calculation results confirmed the enhanced photocatalytic performance and selectivity of VCN was mainly attributed to the effect of N vacancy. On one hand, electron-deficient N vacancy enhanced the adsorption of the O₂ and phenolic compounds, which promoted the production of O₂^•- and strengthened the photocatalytic surface reaction. On the other hand, the N vacancy preferred to adsorb the electron-donating groups of phenolic compounds, which resulted in their selective removal.

Keywords: G-C(3)N(4); N vacancy; Phenolic compounds; Photocatalysis; Selectivity.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Catalysis
Light
Nitrogen*
Phenols
Water Purification* / methods

Substances

Phenols
Nitrogen