Excellent visible light responsive photocatalytic behavior of N-doped TiO2 toward decontamination of organic pollutants

Jiao Huang; Lin Dou; Jianzhang Li; Junbo Zhong; Minjiao Li; Tao Wang

doi:10.1016/j.jhazmat.2020.123857

Excellent visible light responsive photocatalytic behavior of N-doped TiO₂ toward decontamination of organic pollutants

J Hazard Mater. 2021 Feb 5:403:123857. doi: 10.1016/j.jhazmat.2020.123857. Epub 2020 Sep 7.

Authors

Jiao Huang¹, Lin Dou¹, Jianzhang Li¹, Junbo Zhong², Minjiao Li¹, Tao Wang³

Affiliations

¹ Key Laboratory of Green Catalysis of Higher Education Institutes of Sichuan, College of Chemistry and Environment Engineering, Sichuan University of Science and Engineering, Zigong, 643000, PR China.
² Key Laboratory of Green Catalysis of Higher Education Institutes of Sichuan, College of Chemistry and Environment Engineering, Sichuan University of Science and Engineering, Zigong, 643000, PR China. Electronic address: junbozhong@suse.edu.cn.
³ Key Laboratory of Green Catalysis of Higher Education Institutes of Sichuan, College of Chemistry and Environment Engineering, Sichuan University of Science and Engineering, Zigong, 643000, PR China. Electronic address: 3wangtao3@163.com.

PMID: 33264933
DOI: 10.1016/j.jhazmat.2020.123857

Abstract

In this work, N-doped TiO₂ (N-TiO₂) with ample and tunable OVs was successfully synthesized, deriving from facile hydrothermal method and baked in the NH₃ atmosphere. N-doping boosts the amount of surface hydroxyl and superoxide (O₂^-) of TiO₂, demonstrated by XPS and nitroblue tetrazolium (NBT)-O₂^- quantitative reaction. Rich and tunable OVs were confirmed by low temperature electron spin resonance (ESR) results, demonstrating that doping of N into TiO₂ can definitely construct higher OVs than the reference TiO₂. Surface photovoltage spectrum (SPS) test, fluorescence experiments and electrochemical measurements all display that N-TiO₂ photocatalysts with OVs have a higher severance efficiency of photogenerated e-/h⁺ pairs than the pristine TiO₂. Photocatalytic evaluation results exhibit that N-TiO₂ photocatalysts demonstrate better performance than the reference TiO₂ toward decontamination of rhodamine B and tetracycline. TiO₂ treated in ammonia atmosphere for 1 h shows the highest photocatalytic property. The visible light responsive catalytic behavior of TiO₂ treated in ammonia atmosphere for 1 h is much higher than that of commercial TiO₂ (P25) and the pristine TiO₂, separately. The ameliorated visible light behavior of N-TiO₂ photocatalysts is attributable to rich oxygen vacancies produced through introducing N into TiO₂ and the boosted severance of photoactivated e-/h⁺.

Keywords: N-doping; Separation of electrons-holes; TiO(2); Tunable oxygen vacancies; Visible light activity.