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Zhao H, Li CF, Liu LY, Palma B, Hu ZY, Renneckar S, Larter S, Li Y, Kibria MG, Hu J, Su BL. n-p Heterojunction of TiO 2-NiO core-shell structure for efficient hydrogen generation and lignin photoreforming. J Colloid Interface Sci 2020; 585:694-704. [PMID: 33371948 DOI: 10.1016/j.jcis.2020.10.049] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2020] [Revised: 10/08/2020] [Accepted: 10/15/2020] [Indexed: 12/12/2022]
Abstract
Hydrogen evolution from biomass photoreforming has been widely recognized as a promising strategy for relieving the pressure from energy crisis and environmental pollution, as it could generate sustainable H2 and value-added bioproducts simultaneously. Combining p-type semiconductors with n-type semiconductors to form n-p heterojunction is an effective strategy to improve the photocatalytic quantum efficiency by enhancing the separation of photogenerated electrons and holes, which could greatly facilitate the realization of such biomass photorefinery concept. However, the incompact contact between the n-type and p-type semiconductors often induces the aggregation of photogenerated electrons and holes. In this work, we design and synthesize an ultrafine n-p heterojunction TiO2-NiO core-shell structure to overcome the incompact contact in the n-p interface. When the n-p heterojunction photocatalysts are evaluated for photocatalytic water splitting and biomass lignin photoreforming respectively, the as-fabricated TiO2-NiO nanocomposite with 3.25% NiO demonstrates the highest hydrogen generation of 23.5 mmol h-1 g-1 from water splitting and H2 (0.45 mmol h-1 g-1) and CH4 (0.03 mmol h-1 g-1) cogeneration with reasonable amount of fatty acids (palmitic acid and stearic acid) production from lignin photoreforming. The excellent photocatalytic activity is ascribed to the synergistic effects of high crystallinity of TiO2 ultrafine nanoparticles, core-shell structure and n-p heterojunction with NiO nanoclusters. This present work demonstrates a simple and efficient method to fabricate ultrafine n-p heterojunction core-shell structure for noble-metal free catalyst for both water splitting and biomass photoreforming.
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Affiliation(s)
- Heng Zhao
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, 122 Luoshi Road, 430070 Wuhan, Hubei, China; Department of Chemical and Petroleum Engineering, University of Calgary, 2500 University Drive, NW, Calgary, Alberta T2N 1N4, Canada
| | - Chao-Fan Li
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, 122 Luoshi Road, 430070 Wuhan, Hubei, China; Nanostructure Research Centre (NRC), Wuhan University of Technology, 122 Luoshi Road, 430070 Wuhan, Hubei, China
| | - Li-Yang Liu
- Department of Wood Science, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
| | - Bruna Palma
- Department of Chemical and Petroleum Engineering, University of Calgary, 2500 University Drive, NW, Calgary, Alberta T2N 1N4, Canada
| | - Zhi-Yi Hu
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, 122 Luoshi Road, 430070 Wuhan, Hubei, China; Nanostructure Research Centre (NRC), Wuhan University of Technology, 122 Luoshi Road, 430070 Wuhan, Hubei, China
| | - Scott Renneckar
- Department of Wood Science, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
| | - Stephen Larter
- Department of Chemical and Petroleum Engineering, University of Calgary, 2500 University Drive, NW, Calgary, Alberta T2N 1N4, Canada
| | - Yu Li
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, 122 Luoshi Road, 430070 Wuhan, Hubei, China; Nanostructure Research Centre (NRC), Wuhan University of Technology, 122 Luoshi Road, 430070 Wuhan, Hubei, China.
| | - Md Golam Kibria
- Department of Chemical and Petroleum Engineering, University of Calgary, 2500 University Drive, NW, Calgary, Alberta T2N 1N4, Canada.
| | - Jinguang Hu
- Department of Chemical and Petroleum Engineering, University of Calgary, 2500 University Drive, NW, Calgary, Alberta T2N 1N4, Canada.
| | - Bao-Lian Su
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, 122 Luoshi Road, 430070 Wuhan, Hubei, China; Laboratory of Inorganic Materials Chemistry (CMI), University of Namur, 61 rue de Bruxelles, B-5000 Namur, Belgium.
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Smerieri M, Pal J, Savio L, Vattuone L, Ferrando R, Tosoni S, Giordano L, Pacchioni G, Rocca M. Spontaneous Oxidation of Ni Nanoclusters on MgO Monolayers Induced by Segregation of Interfacial Oxygen. J Phys Chem Lett 2015; 6:3104-3109. [PMID: 26267209 DOI: 10.1021/acs.jpclett.5b01362] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We report the study of Ni nanoclusters deposited on MgO/Ag(100) ultrathin films (one monolayer) at T = 200 K. We show by STM analysis and DFT calculations that in the limit of low Ni coverage the formation of nanoclusters of four to six atoms occurs and that these aggregates are flat rather than 3D, as expected for Ni tetramers, pentamers, or hexamers. Both the shape of the clusters and the interatomic distance between neighboring Ni atoms are indicative that the nanoparticles do not consist of pure metal atoms but that a NiyOx structure has formed thanks to the availability of atomic oxygen accumulated at the MgO/Ag interface, with Ni clusters acting as oxygen pumps. Besides being of relevance in view of the use of metal nanoclusters in catalysis and other applications, this finding gives a further proof of the peculiar behavior of ultrathin oxide films.
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Affiliation(s)
- M Smerieri
- †IMEM-CNR, U.O.S. Genova, Via Dodecaneso 33, 16146 Genova, Italy
| | - J Pal
- †IMEM-CNR, U.O.S. Genova, Via Dodecaneso 33, 16146 Genova, Italy
- ‡Dipartimento di Fisica, Università di Genova, Via Dodecaneso 33, 16146 Genova, Italy
| | - L Savio
- †IMEM-CNR, U.O.S. Genova, Via Dodecaneso 33, 16146 Genova, Italy
| | - L Vattuone
- †IMEM-CNR, U.O.S. Genova, Via Dodecaneso 33, 16146 Genova, Italy
- ‡Dipartimento di Fisica, Università di Genova, Via Dodecaneso 33, 16146 Genova, Italy
| | - R Ferrando
- †IMEM-CNR, U.O.S. Genova, Via Dodecaneso 33, 16146 Genova, Italy
- §Dipartimento di Chimica e Chimica Industriale, Università di Genova, Via Dodecaneso 31, 16146 Genova, Italy
| | - S Tosoni
- ∥Dipartimento di Scienza dei Materiali, Università Milano Bicocca, via R. Cozzi 55, 20125 Milano, Italy
| | - L Giordano
- ∥Dipartimento di Scienza dei Materiali, Università Milano Bicocca, via R. Cozzi 55, 20125 Milano, Italy
| | - G Pacchioni
- ∥Dipartimento di Scienza dei Materiali, Università Milano Bicocca, via R. Cozzi 55, 20125 Milano, Italy
| | - M Rocca
- †IMEM-CNR, U.O.S. Genova, Via Dodecaneso 33, 16146 Genova, Italy
- ‡Dipartimento di Fisica, Università di Genova, Via Dodecaneso 33, 16146 Genova, Italy
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