Selective reduction of nitrate into N2 by novel Z-scheme NH2-MIL-101(Fe)/BiVO4 heterojunction with enhanced photocatalytic activity

Huilong Shi; Chunhu Li; Liang Wang; Wentai Wang; Xiangchao Meng

doi:10.1016/j.jhazmat.2021.127711

Selective reduction of nitrate into N₂ by novel Z-scheme NH₂-MIL-101(Fe)/BiVO₄ heterojunction with enhanced photocatalytic activity

J Hazard Mater. 2022 Feb 15;424(Pt D):127711. doi: 10.1016/j.jhazmat.2021.127711. Epub 2021 Nov 7.

Authors

Huilong Shi¹, Chunhu Li², Liang Wang¹, Wentai Wang¹, Xiangchao Meng³

Affiliations

¹ Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao 266100, China.
² Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao 266100, China. Electronic address: lichunhu@ouc.edu.cn.
³ Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao 266100, China. Electronic address: mengxiangchao@ouc.edu.cn.

PMID: 34799158
DOI: 10.1016/j.jhazmat.2021.127711

Abstract

Nitrate and its metabolites as common pollutants in water had attracted widespread attentions. Converting nitrate to nontoxic and harmless nitrogen via photocatalysis was a promising approach. In this study, a novel Z-scheme NH₂-MIL-101(Fe)/BiVO₄ heterojunction was successfully prepared. As-prepared Z-scheme heterojunction along with built-in electric field facilitated the charge separation and enhanced the photocatalytic activity in nitrate reduction. The results showed that 0.10-MBiVO photocatalyst exhibited the highest nitrate removal rate of 94.8% (initial concentration 100 mgN/L) and final selectivity to N₂ of 93.4% in 50 min under ultraviolet irradiation. Moreover, formic acid was proved as better hole scavenger compared with methanol and oxalic acid. And the concentration of formic acid had significant influence on the process of nitrate photocatalytic reduction. 0.10-MBiVO photocatalyst exhibited excellent reusability in the recycling tests, indicating its great potential in practical application of nitrate photocatalytic removal. The mechanism of the enhancement as well as reaction pathways for nitrate photocatalytic reduction on NH₂-MIL-101(Fe)/BiVO₄ were comprehensively explored and described at the end.

Keywords: BiVO(4); NH(2)-MIL-101(Fe); Z-scheme; nitrate reduction; photocatalysis.