Synergistic effect of surface oxygen vacancies and hydroxyl groups on Cu-doped TiO2 photocatalyst for hydrogen evolution
Xing, Congcong (Universitat Politècnica de Catalunya. Centre de Recerca en Ciencia i Enginyeria Multiescala de Barcelona)
Zhang, Zhaofu (Wuhan University. The Institute of Technological Sciences)
Zhang, Yu (Institut de Recerca en Energia de Catalunya)
Han, Xu (Institut Català de Nanociència i Nanotecnologia)
Yang, Linlin (Institut de Recerca en Energia de Catalunya)
Li, Junshan (Chengdu University. Institute for Advanced Study)
Wang, Xiang (Institut de Recerca en Energia de Catalunya)
Martinez, Paulina (Institut de Recerca en Energia de Catalunya)
Demir, Muslum (Osmaniye Korkut Ata University. Department of Chemical Engineering)
Piveteau, Laura (Centre National de la Recherche Scientifique (França))
Florian, Pierre (Centre National de la Recherche Scientifique (França))
Arbiol i Cobos, Jordi (Institut Català de Nanociència i Nanotecnologia)
Guo, Yuzheng (Wuhan University)
Llorca, Jordi (Universitat Politècnica de Catalunya. Centre de Recerca en Ciencia i Enginyeria Multiescala de Barcelona)
Cabot i Codina, Andreu (Institut de Recerca en Energia de Catalunya)

Date:	2023
Abstract:	The intricate nature of the titanium dioxide (TiO2) photocatalytic system, influenced by Cu doping, often yields conflicting outcomes. This study addresses this complexity by examining the impact of Cu ion doping in nanostructured TiO2 to augment its photocatalytic efficacy in hydrogen generation from ethanol-water mixtures. The improved performance is primarily attributed to the generation of oxygen vacancies (Ovac) within the TiO2 lattice. By adjusting the thermal processing parameters, the chemical state of Cu is modulated to optimize photocatalytic performance. Solid-state nuclear magnetic resonance (SSNMR) and density functional theory (DFT) calculations confirm that the presence of Ovac and hydroxyl groups (OH-) surface species not only facilitates local spatial charge separation but also enhances light absorption, thereby improving photocatalytic hydrogen evolution reaction (HER) rate up to 20. 2 mmol h-1 g-1 under UV light. Furthermore, a proposed mechanism involves the participation of Ovac and OH- species, supported by Mott-Schottky (M - S) plots and ultraviolet photoelectron spectroscopy (UPS), revealing that Cu-TiO2 exhibits a lower flat band potential (Efb) and smaller work function compared to TiO2. This research underscores the pivotal role of Cu ions and Ovac:OH- in advancing the photocatalytic activity of TiO2-based crystals, imparting noteworthy implications for sustainable hydrogen generation.
Grants:	Agencia Estatal de Investigación PID2021-124572OB-C31 Agencia Estatal de Investigación PID2019-105490RB-C32 Agència de Gestió d'Ajuts Universitaris i de Recerca 2021/SGR-00457 Agencia Estatal de Investigación PID2020-116093RB-C43 Ministerio de Ciencia e Innovación CEX2021-001214-S
Rights:	Aquest material està protegit per drets d'autor i/o drets afins. Podeu utilitzar aquest material en funció del que permet la legislació de drets d'autor i drets afins d'aplicació al vostre cas. Per a d'altres usos heu d'obtenir permís del(s) titular(s) de drets.
Language:	Anglès
Document:	Article ; recerca ; Versió sotmesa a revisió
Subject:	Titanium dioxide ; Oxygen vacancy ; Hydroxyl group ; Photocatalysis ; Hydrogen
Published in:	Materials Today Nano, Vol. 24 (December 2023) , art. 100435, ISSN 2588-8420

DOI: 10.1016/j.mtnano.2023.100435

Preprint 27 p, 2.9 MB

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Research literature > UAB research groups literature > Research Centres and Groups (research output) > Experimental sciences > Catalan Institute of Nanoscience and Nanotechnology (ICN2)
Articles > Research articles
Articles > Published articles