Jump to main content
Jump to site search

Issue 20, 2020
Previous Article Next Article

Oxygen vacancies enhance photocatalytic removal of NO over an N-doped TiO2 catalyst

Author affiliations

Abstract

In this study, a non-metallic N-doped TiO2 photocatalyst (N–TiO2) was fabricated via facile co-deposition methods using titanium isopropoxide (Ti(OC3H7)4) and ammonia as precursors, and exhibited superior photocatalytic activity and selectivity to pure TiO2 on the degradation of NO under visible light irradiation at room temperature. The results of in situ diffuse reflectance infrared Fourier transform spectroscopy (in situ DRIFTS) suggested that NO was mainly adsorbed at Ti4+ sites, and then formed the NO+ active intermediates under visible light illumination. The co-adsorption of NO and molecular oxygen results indicated that the generation of the NO3 product over N–TiO2 was mainly attributed to the interaction between the NO species adsorbed on the catalyst surface and active oxygen (O) rather than the surface hydroxyl. Moreover, the UV-vis diffuse reflectance spectra (DRS), photoluminescence (PL) and the photocurrent and electron paramagnetic resonance (EPR) results showed that TiO2 doped with N atoms not only enhanced the utilization efficiency of photo-generated charge carriers, but also promoted the formation of surface defects (e.g., oxygen vacancies) under visible light irradiation. Combined with X-ray photoelectron spectroscopy (XPS) and the O2 temperature-programmed desorption (O2-TPD) measurement analyses, it was found that oxygen vacancies not only facilitated the absorption and activation of molecular oxygen but also acted as a bridge between molecular oxygen and lattice oxygen in the catalyst (Ti4+ ↔ Ti3+). This resulted in an outstanding oxygen circulation between the Ti4+ and Ti3+ sites during the NO oxidation process under visible light irradiation. Thus, an enhanced NO removal efficiency and photocatalytic stability for NO oxidation occurred on N–TiO2.

Graphical abstract: Oxygen vacancies enhance photocatalytic removal of NO over an N-doped TiO2 catalyst

Back to tab navigation

Supplementary files

Article information


Submitted
11 Jul 2020
Accepted
13 Aug 2020
First published
17 Aug 2020

Catal. Sci. Technol., 2020,10, 6923-6934
Article type
Paper

Oxygen vacancies enhance photocatalytic removal of NO over an N-doped TiO2 catalyst

X. Tan, G. Qin, G. Cheng, X. Song, X. Chen, W. Dai and X. Fu, Catal. Sci. Technol., 2020, 10, 6923
DOI: 10.1039/D0CY01394C

Social activity

Search articles by author

Spotlight

Advertisements