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Li F, Liu G, Liu F, Wu J, Yang S. Synergetic effect of CQD and oxygen vacancy to TiO 2 photocatalyst for boosting visible photocatalytic NO removal. JOURNAL OF HAZARDOUS MATERIALS 2023; 452:131237. [PMID: 36948124 DOI: 10.1016/j.jhazmat.2023.131237] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 03/03/2023] [Accepted: 03/16/2023] [Indexed: 06/18/2023]
Abstract
The wide band gap of TiO2 photocatalyst material limits its application in the field of visible photocatalysis. In this paper, oxygen vacancies and carbon quantum dots (CQD) with up-conversion character were proposed to improve the photocatalytic activity for NO removal of TiO2 under visible light irradiation. The one-dimensional TiO2 nanotube (TNs), TNs containing oxygen vacancies (OVTNs), TNs of composite CQD (CQD-TNs) and OVTNs of composite CQD (CQD-OVTNs) were prepared, respectively. Furthermore, the influence of oxygen vacancies and CQD on the removal of NOx by photocatalysis were explored. It is found that CQD-OVTNs exhibits the conspicuous synergetic effect of CQD and oxygen vacancy to boost visible photocatalytic NO removal, the NO removal efficiency was about 12, 2, and 2.6 times to TNs, OVTNs and CQD-TNs. Also, CQD-OVTNs exhibits the NO2-inhibited property during the process of photocatalytic NO removal. Finally, the synergetic mechanism of CQD and oxygen vacancies to TNs for boosting visible photocatalytic NO removal was revealed.
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Affiliation(s)
- Fen Li
- College of Chemistry & Environmental Science, Hebei University, Baoding 071002, China
| | - Guanyu Liu
- College of Civil Engineering and Architecture, Hebei University, Baoding 071002, China; Technology Innovation Center for Testing and Evaluation in Civil Engineering of Hebei Province, Baoding 071002, China.
| | - Fuqiang Liu
- College of Civil Engineering and Architecture, Hebei University, Baoding 071002, China; Technology Innovation Center for Testing and Evaluation in Civil Engineering of Hebei Province, Baoding 071002, China
| | - Jiayu Wu
- School of Civil and Transportation Engineering, Ningbo University of Technology, Ningbo 315016, China
| | - Sanqiang Yang
- College of Civil Engineering and Architecture, Hebei University, Baoding 071002, China; Technology Innovation Center for Testing and Evaluation in Civil Engineering of Hebei Province, Baoding 071002, China
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Ma H, Yang W, Tang H, Pan Y, Li W, Fang R, Shen Y, Dong F. Enhance the stability of oxygen vacancies in SrTiO 3 via metallic Ag modification for efficient and durable photocatalytic NO abatement. JOURNAL OF HAZARDOUS MATERIALS 2023; 452:131269. [PMID: 36989778 DOI: 10.1016/j.jhazmat.2023.131269] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Revised: 03/14/2023] [Accepted: 03/21/2023] [Indexed: 06/19/2023]
Abstract
Oxygen vacancy engineering is an appealing strategy in the direction of photocatalytic pollutant purification. Unfortunately, the short lifetime of oxygen vacancies significantly limits photocatalytic efficiencies and their application. Herein, we report that such a scenario can be resolved via plasmonic silver metal modification SrTiO3 containing oxygen vacancies, which can achieve a high NO removal rate of 70.0% and long stability. This outstanding photocatalytic activity can be attributed to the increased optical response range and carrier separation by metallic Ag with the unique character of localized surface plasmonic resonance (LSPR) effect. Moreover, the intrinsic mechanism of how the plasmonic metal could enhance the stability of oxygen vacancies is proposed. The plasmon-driven hot carriers inject SrTiO3 support that promotes the regeneration of oxygen vacancies around the interface, meanwhile, the introduction of Ag nanoparticles prevents the oxygen vacancies from being filled by the reactant. This work elucidates the unique role of plasmonic metal in photocatalysis, providing an innovative idea for improving catalytic stability.
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Affiliation(s)
- Hao Ma
- National Research Base of Intelligent Manufacturing Service, Chongqing Technology and Business University, Chongqing 400067, China.
| | - Wenjia Yang
- National Research Base of Intelligent Manufacturing Service, Chongqing Technology and Business University, Chongqing 400067, China; Chongqing Energy Utilization Monitoring Center, Chongqing Energy Saving Technology Service Center, Chongqing 400000, China
| | - Hongyi Tang
- National Research Base of Intelligent Manufacturing Service, Chongqing Technology and Business University, Chongqing 400067, China
| | - Yue Pan
- National Research Base of Intelligent Manufacturing Service, Chongqing Technology and Business University, Chongqing 400067, China
| | - Wenting Li
- National Research Base of Intelligent Manufacturing Service, Chongqing Technology and Business University, Chongqing 400067, China
| | - Ruimei Fang
- National Research Base of Intelligent Manufacturing Service, Chongqing Technology and Business University, Chongqing 400067, China
| | - Yu Shen
- National Research Base of Intelligent Manufacturing Service, Chongqing Technology and Business University, Chongqing 400067, China
| | - Fan Dong
- National Research Base of Intelligent Manufacturing Service, Chongqing Technology and Business University, Chongqing 400067, China; Yangtze Delta Region Institute (Huzhou), University of Electronic Science and Technology of China, Huzhou 313000, China; State Centre for International Cooperation on Designer Low carbon and Environmental Materials (CDLCEM), School of Materials Science and Engineering, Zhengzhou University, Zhengzhou 450001, China
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Li F, Liu G, Liu F, Yang S. A WO 3-TiO 2 nanorod/CaCO 3 photocatalyst with degradation-regeneration double sites for NO 2-inhibited and durable photocatalytic NO. CHEMOSPHERE 2023; 324:138277. [PMID: 36889473 DOI: 10.1016/j.chemosphere.2023.138277] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Revised: 02/26/2023] [Accepted: 02/27/2023] [Indexed: 06/18/2023]
Abstract
As a promising cleaner technology for nitric oxide degradation, photocatalysis has attracted extensive attention, while the main limitations of photocatalytic nitric oxide are that the toxic NO2 is produced easily and the photocatalytic durability was inferior due to the accumulation of photocatalytic products. In this paper, a WO3-TiO2 nanorod/CaCO3 (TCC) insulating heterojunction photocatalyst with degradation-regeneration double sites was prepared by simple grinding and calcining. The effects of CaCO3 loading on the morphology, microstructure and composition of TCC photocatalyst were investigated by SEM, TEM, XRD, FT-IR and XPS etc. Also, TCC exhibits NO2-inhibited and durable characteristics for NO degradation. DFT calculation, the detection of active radicals by EPR, capture test and the NO degradation pathway characterized by in-situ FT-IR spectra showed that the electron-rich region formed and the existence of regeneration sites are the main reasons for promoting the NO2-inhibited and durable NO degradation. Furthermore, the mechanism of NO2-inhibited and durable NO degradation by TCC was revealed. Finally, TCC superamphiphobic photocatalytic coating was prepared, which still exhibits similar NO2-inhibited and durable characteristics for NO degradation to TCC photocatalyst. It may provide new application value and development prospects in the field of photocatalytic NO.
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Affiliation(s)
- Fen Li
- College of Chemistry & Environmental Science Hebei University, Baoding, 071002 China
| | - Guanyu Liu
- College of Civil Engineering and Architecture, Hebei University, Baoding, China; Technology Innovation Center for Testing and Evaluation in Civil Engineering of Hebei Province, Baoding, China.
| | - Fuqiang Liu
- College of Civil Engineering and Architecture, Hebei University, Baoding, China; Technology Innovation Center for Testing and Evaluation in Civil Engineering of Hebei Province, Baoding, China
| | - Sanqiang Yang
- College of Civil Engineering and Architecture, Hebei University, Baoding, China; Technology Innovation Center for Testing and Evaluation in Civil Engineering of Hebei Province, Baoding, China
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Photocatalytic degradation of gaseous pollutants on nanostructured TiO 2 films of various thickness and surface area. PHOTOCHEMICAL & PHOTOBIOLOGICAL SCIENCES : OFFICIAL JOURNAL OF THE EUROPEAN PHOTOCHEMISTRY ASSOCIATION AND THE EUROPEAN SOCIETY FOR PHOTOBIOLOGY 2023; 22:883-892. [PMID: 36745319 DOI: 10.1007/s43630-022-00359-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Accepted: 12/23/2022] [Indexed: 02/07/2023]
Abstract
This work deals with the preparation of TiO2 nanoparticulate layers of various mass (0.05 mg/cm2 to 2 mg/cm2) from three commercial nanopowder materials, P90, P25 and CG 300, their characterisation (profilometry, BET and SEM) and evaluation of their photocatalytic activity in the gaseous phase in a flow-through photoreactor according to the ISO standard (ISO 22197-2). Hexane was chosen as a single model pollutant and a mixture of four compounds, namely acetaldehyde, acetone, heptane and toluene was used for the evaluation of the efficiency of simultaneous removal of several pollutants. A linear dependence between the layer mass and the layer thickness for all materials was found. Up to a layer mass 0.5 mg/cm2, the immobilisation P90 and P25 powder did not result in a decrease in BET surface area, whereas with an increase in layer mass to 1 mg/cm2, a decrease of the BET surface was observed, being more significant in the case of P90. The photocatalytic conversion of hexane was comparable for all immobilised powders up to a layer mass of 0.5 mg/cm2. For higher layer mass, the photocatalytic conversion of hexane on P25 and P90 differ; the latter achieved about 30% higher conversion. In the case of the simultaneous degradation of four compounds, acetaldehyde was degraded best, followed by acetone and toluene; the least degraded compound was heptane. The measurement of released CO2 revealed that 90% of degraded hexane was mineralised to CO2 and water while for a mixture of 4 VOCs, the level of mineralisation was 83%.
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Abstract
The ISO standard 22197-1:2016 used for the evaluation of the photocatalytic nitric oxide removal has a main drawback, which allows only the decrease of nitric oxide to be determined specifically. The remaining amount, expressed as “NO2”, is considered as a sum of HNO3, HONO NO2, and other nitrogen-containing species, which can be potentially formed during the photocatalytic reaction. Therefore, we developed a new methodology combining our custom-made analyzers, which can accurately determine the true NO2 and HONO species, with the conventional NO one. Their function was validated via a photocatalytic experiment in which 100 ppbv of either NO or NO2 dispersed in air passed over (3 L min−1) an Aeroxide© TiO2 P25 surface. The gas-phase analysis was complemented with the spectrophotometric determination of nitrates (NO3−) and/or nitrites (NO2−) deposited on the P25 layer. Importantly, an almost perfect mass balance (94%) of the photocatalytic NOx abatement was achieved. The use of custom-made analyzers enables to obtain (i) no interference, (ii) high sensitivity, (iii) good linearity in the relevant concentration range, (iv) rapid response, and (v) long-term stability. Therefore, our approach enables to reveal the reaction complexity and is highly recommended for the photocatalytic NOx testing.
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Zhou R, Han R, Bingham M, O'Rourke C, Mills A. 3D printed, plastic photocatalytic flow reactors for water purification. Photochem Photobiol Sci 2022; 21:1585-1600. [PMID: 35608816 DOI: 10.1007/s43630-022-00242-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Accepted: 05/03/2022] [Indexed: 10/18/2022]
Abstract
3D printing is known as a fast, inexpensive, reproducible method for producing prototypes but is also fast becoming recognised as a scalable, advanced manufacture process. Two types of lab-scale, 3D printed plastic, fixed-film, flow-through photocatalytic reactors are described, both of which are sinusoidal in shape, and only differ in that one has no baffles, reactor A, whereas the other has, reactor B. Both reactors are lined with a P25 TiO2/polylactic acid (PLA) coating, which, after UVA pre-conditioning, is used to photocatalyse the bleaching of circulating aqueous solutions of either methylene blue, MB, or phenol, PhOH, repeatably, without any obvious loss of activity. The rate of the photocatalysed bleaching of MB exhibited by reactor B shows a much lower dependence upon flow rate than reactor A, due to the greater lateral mixing of the laminar flow streams produced by the baffles. The photonic efficiencies of reactor A for the photocatalysed bleaching of MB and PhOH were determined to be 0.025% and 0.052%, respectively, and the photocatalytic space-time yields (PSTY) to be 0.98 × 10-4 and 1.49 × 10-4 m3 of reaction solution.m-3 reactor volume.day-1.kW-1, respectively. This is the first example of an all plastic, 3D printed photocatalytic reactor and demonstrates the advantages of 3D printing for prototyping. Given the 3D printing is a scalable process, possible potential areas of application are discussed briefly.
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Affiliation(s)
- Ruicheng Zhou
- School of Chemistry and Chemical Engineering, Queens University Belfast, Stranmillis Road, Belfast, BT9 5AG, UK
| | - Ri Han
- School of Chemistry and Chemical Engineering, Queens University Belfast, Stranmillis Road, Belfast, BT9 5AG, UK
| | - Michael Bingham
- School of Chemistry and Chemical Engineering, Queens University Belfast, Stranmillis Road, Belfast, BT9 5AG, UK
| | - Christopher O'Rourke
- School of Chemistry and Chemical Engineering, Queens University Belfast, Stranmillis Road, Belfast, BT9 5AG, UK
| | - Andrew Mills
- School of Chemistry and Chemical Engineering, Queens University Belfast, Stranmillis Road, Belfast, BT9 5AG, UK.
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