Charge transfer processes involved in photocatalytic hydrogen production over CuO/ZrO2–TiO2 materials. (13th April 2017)

• Record Type: Journal Article
• Authors: Guerrero-Araque, Diana; Acevedo-Peña, Próspero; Ramírez-Ortega, David; Calderon, Héctor A.; Gómez, Ricardo
• Is Part Of: International journal of hydrogen energy. Volume 42:Number 15(2017)
• Page Start: 9744
• Page End: 9753
• Publication Date: 2017-04-13
• Subjects: Hydrogen production -- Charge transfer process -- Co-catalysts -- Interface -- CuO content; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2017.03.050
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: Co-catalysts are widely employed to boost the photocatalytic hydrogen production; particularly, CuO has shown a remarkable improvement in the reaction rate. However, the impact of CuO on the charge transfer process during photocatalytic water reduction has been barely investigated. In this work, ZrO2 –TiO2 (ZT) heterojunctions (5 mol% ZrO2 ) have been obtained by means of the sol–gel method. Subsequently, copper nitrate impregnations are prepared by an incipient wetness impregnation method to get 0.5, 1, 3 and 5 wt% CuO loadings. A maximum in the photocatalytic activity is observed for the material containing 1 wt% CuO, followed by a drastic drop in the hydrogen generation rate. Electrochemical characterization shows that the charge-transfer resistance controls the photocatalytic experiments together with the additional interfacial resistance. The maximum photocatalytic activity is then given by a compromise between these two parameters. A further increase of the additional resistance, directly proportional to the CuO loading, reduces drastically the photocatalytic behavior most likely due to the electron trapping at the ZT–CuO interface. Graphical abstract: Image 1 Highlights: CuO is an attractive co-catalyst for the water reduction. 1% wt CuO and ZrO2 –TiO2 exhibits the highest photocatalytic activity. Interfacial resistance hinders the photocatalytic process at higher CuO loading.