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Liu M, Zhang G, Ming R, Fu X, Jiang R, Tian L, Chen X. Reconstruction of Highly-Defective MgO and Exceptional Photochemical Activity on CO 2 Upgrade in Aqueous Solution. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2023; 19:e2303405. [PMID: 37431200 DOI: 10.1002/smll.202303405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2023] [Revised: 06/21/2023] [Indexed: 07/12/2023]
Abstract
Defects on metal oxide have attracted extensive attention in photo-/electrocatalytic CO2 reduction. Herein, porous MgO nanosheets with abundant oxygen vacancies (Vo s) and three-coordinated oxygen atoms (O3c ) at corners are reported, which reconstruct into defective MgCO3 ·3H2 O exposing rich surface unsaturated -OH groups and vacancies to initiate photocatalytic CO2 reduction to CO and CH4 . In consecutive 7-cycle tests (each run for 6 h) in pure water, CO2 conversion keeps stable. The total production of CH4 and CO attains ≈367 µmol gcata -1 h-1 . The selectivity of CH4 gradually increases from ≈3.1% (1st run) to ≈24.5% (4th run) and then remains unchanged under UV-light irradiation. With triethanolamine (3.3 vol.%) as the sacrificial agent, the total production of CO and CH4 production rapidly increases to ≈28 000 µmol gcata -1 in 2 h reaction. Photoluminescence spectra reveal that Vo s induces the formation of donor bands to promote charge carrier seperation. A series of trace spectra and theoretical analysis indicate Mg-Vo sites in the derived MgCO3 ·3H2 O are active centers, which play a crucial role in modulating CO2 adsorption and triggering photoreduction reactions. These intriguing results on defective alkaline earth oxides as potential photocatalysts in CO2 conversion may spur some exciting and novel findings in this field.
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Affiliation(s)
- Mengping Liu
- Hubei Collaborative Innovation Center for Advanced Organochemical Materials, Ministry-of-Education Key Laboratory for the Synthesis and Applications of Organic Functional Molecules, Hubei University, Wuhan, 430062, P. R. China
| | - Ganbing Zhang
- Hubei Collaborative Innovation Center for Advanced Organochemical Materials, Ministry-of-Education Key Laboratory for the Synthesis and Applications of Organic Functional Molecules, Hubei University, Wuhan, 430062, P. R. China
| | - Ruiqi Ming
- Hubei Collaborative Innovation Center for Advanced Organochemical Materials, Ministry-of-Education Key Laboratory for the Synthesis and Applications of Organic Functional Molecules, Hubei University, Wuhan, 430062, P. R. China
| | - Xin Fu
- Hubei Collaborative Innovation Center for Advanced Organochemical Materials, Ministry-of-Education Key Laboratory for the Synthesis and Applications of Organic Functional Molecules, Hubei University, Wuhan, 430062, P. R. China
| | - Ruiyi Jiang
- Hubei Collaborative Innovation Center for Advanced Organochemical Materials, Ministry-of-Education Key Laboratory for the Synthesis and Applications of Organic Functional Molecules, Hubei University, Wuhan, 430062, P. R. China
| | - Lihong Tian
- Hubei Collaborative Innovation Center for Advanced Organochemical Materials, Ministry-of-Education Key Laboratory for the Synthesis and Applications of Organic Functional Molecules, Hubei University, Wuhan, 430062, P. R. China
| | - Xiaobo Chen
- Division of Energy, Matter, and Systems, School of Science and Engineering, University of Missouri - Kansas City, Kansas City, MO 64110, USA
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Structure sensitivity of the oxidative activation of methane over MgO model catalysts: II. Nature of active sites and reaction mechanism. J Catal 2015. [DOI: 10.1016/j.jcat.2015.05.008] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Sternig A, Müller M, McCallum M, Bernardi J, Diwald O. BaO clusters on MgO nanocubes: a quantitative analysis of optical-powder properties. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2010; 6:582-8. [PMID: 20029851 DOI: 10.1002/smll.200901662] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Uniformly sized and shaped nanoparticles are well suited for the quantitative characterization of optical-powder properties. For the first time, quantum yields related to photoluminescence emissions that originate from the photoexcitation of MgO nanocube corners and edges are measured. In addition, the surfaces of these nanoparticles are doped with submonolayer barium, which oxidizes during adsorption onto the MgO nanocrystal surfaces and transforms in O(2) atmosphere into BaO. UV-Vis diffuse reflectance and photoluminescence spectroscopy is employed to explore whether 10(-3) monolayer equivalents of these dopants affect the MgO specific optical properties. Surface-admixed BaO produces additional absorption and photoluminescence emission features but does not significantly affect those specific to MgO nanocubes. On this basis the number of optically active sites that can be sampled inside a powder of alkaline earth oxide nanoparticles using a standard spectrometer system is estimated.
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Affiliation(s)
- Andreas Sternig
- Institute of Materials Chemistry, Vienna University of Technology, Veterinärplatz 1/GA, Vienna 1210, Austria
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Chapter 1 Applications of Photoluminescence Spectroscopy to the Investigation of Oxide‐Containing Catalysts in the Working State. ADVANCES IN CATALYSIS 2009. [DOI: 10.1016/s0360-0564(08)00001-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register]
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