Visible light-driven novel Bi₂Ti₂O₇/CaTiO₃ composite photocatalyst with enhanced photocatalytic activity towards NO removal

authored by

Menglin Shi, Baker Rhimi, Ke Zhang, Jingkun Xu, Detlef W. Bahnemann, Chuanyi Wang

Abstract

Photocatalysis is regarded as a promising technology for removal of nitrogen oxide (NO), however, the low photocatalytic efficiencies under visible light irradiation and the deactivation of the photocatalyst are as yet the significant issues that should be addressed. In this work, visible-light-driven Bi₂Ti₂O₇/CaTiO₃ heterojunction composites were synthesized by a facile in-situ hydrothermal method. The Bi₂Ti₂O₇/CaTiO₃ composites displayed superior visible light photocatalytic activity than pure CaTiO₃ and pure Bi₂Ti₂O₇ in the removal of NO at the 600 ppb level in air. Among all the composites, Bi₂Ti₂O₇/CaTiO₃ containing 20 wt% Bi₂Ti₂O₇ exhibited the best photocatalytic activity, achieving a maximum removal efficiency of 59%. The improved photocatalytic performance is mainly attributed to the strong visible-light-absorbing ability, the presence of an appropriate density of oxygen vacancy defects and the formation of heterojunction between CaTiO₃ and Bi₂Ti₂O₇, resulting in an efficient charge separation at the interface as proven by photoluminescence (PL) and photo-induced current measurements. According to trapping experiments and spin-trapping ESR analysis, the ^•O₂⁻ and h⁺ are the principal reactive species involved in the photocatalytic NO removal. In addition, the as-obtained Bi₂Ti₂O₇/CaTiO₃ composite showed good chemical stability, which is beneficial for practical applications in air pollution removal.

Organisation(s)

Institute of Technical Chemistry

External Organisation(s)

Shaanxi University of Science and Technology
Jiangxi Science and Technology Normal University
Saint Petersburg State University

Type

Article

Journal

Chemosphere

Volume

275

ISSN

0045-6535

Publication date

07.2021

Publication status

Published

Peer reviewed

Yes

ASJC Scopus subject areas

Environmental Engineering, General Chemistry, Environmental Chemistry, Pollution, Public Health, Environmental and Occupational Health, Health, Toxicology and Mutagenesis

Sustainable Development Goals

SDG 3 - Good Health and Well-being

Electronic version(s)

https://doi.org/10.1016/j.chemosphere.2021.130083 (Access: Closed)