Fabrication of CuO/ZnO composite films with cathodic co-electrodeposition and their photocatalytic performance

• Published in: Journal of molecular catalysis. A, Chemical Chemical, 2010-10, Vol.331 (1), p.112-116
• Main Authors: Wei, Shouqiang, Chen, Yuye, Ma, Yuyan, Shao, Zhongcai
• Format: Article
• Language: English
• Subjects: Catalysis; Cathodic co-electrodeposition; Chemistry; CuO/ZnO composite films; Exact sciences and technology; General and physical chemistry; Heterostructures; Hexavalent chromium; Photocatalytic reduction; Photochemistry; Physical chemistry of induced reactions (with radiations, particles and ultrasonics); Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry
• ISSN: 1381-1169; 1873-314X
• DOI: 10.1016/j.molcata.2010.08.011

This report presents cathodic co-electrodeposition of CuO/ZnO films and application for photoreduction of Cr(VI). Their improved photocatalytic activity can be partly attributed to a efficient interfacial separation of charges. [Display omitted] ▶ CuO/ZnO composite films are fabricated with cathodic co-electrodeposition. ▶ Cu-doped ZnO film is obtained from a bath with low Cu 2+ concentration. ▶ CuO/ZnO composite films have high photocatalytic activity. ▶ Photocatalytic activity is related to atomic Cu/Zn ratios in the films. ▶ Enhancement of activity is attributed to the efficient separation of charges. CuO/ZnO composite films with different atomic Cu/Zn ratios were for the first time fabricated on indium tin oxide (ITO)-coated glass substrates via a cathodic co-electrodeposition route from baths containing Zn(NO 3) 2 and Cu(CH 3COO) 2. The obtained composite films were characterized with X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). Hexavalent chromium (Cr(VI)) was used as a model pollutant to evaluate their photocatalytic activity. For a bath containing Zn(NO 3) 2 with a certain concentration, the concentration of Cu 2+ ions added into this bath play an important role in fabrication of CuO/ZnO composite films. When the Cu 2+ concentration in a bath is lower, the obtained composite is a Cu-doped ZnO film. The electrodeposited CuO/ZnO composite films show higher photocatalytic activity towards reduction of Cr(VI) compared to pure ZnO both under UV and under UV–vis light illumination. Furthermore, the photocatalytic activity of CuO/ZnO composite films is related to their atomic Cu/Zn ratios. The mechanism of CuO/ZnO composite films for improvement in photocatalytic activity was also discussed.