Solar Energy Materials and Solar Cells, Vol.134, 309-317, 2015
Fabrication of an efficient noble metal-free TiO2-based photocatalytic system using Cu-Ni bimetallic deposit as an active center of H-2 evolution from water
Cu and Ni co-modified TiO2 nanoparticles (P25) were prepared by a simple hydrothermal process. Meanwhile, photocatalytic H-2 evolution from water over the as-prepared Cu and Ni co-modified TiO2 nanoparticles was explored using methanol as a sacrificial reagent. The results indicate that the Cu and Ni co-modified TiO2 nanoparticles is an efficient and stable photocatalyst for photocatalytic hydrogen evolution from methanol aqueous solution. During the first 5-h irradiation, the rate is up to 13.5 mmol h(-1) g(-1). Moreover, the photocatalytic activity of the Cu and Ni co-modified TiO2 nanoparticles can remain almost unchanged after two successive cycles. And the hydrogen evolution rate is still up to 4.62 mmol h(-1) g(-1) in the eighth cycle. Therein, Cu-Ni bimetallic deposit serves as charge transferring sites and/or active sites, and plays an important role in the photocatalytic hydrogen evolution. The dramatic photocatalytic activity of the Cu and Ni co-modified TiO2 nanoparticles may be ascribed to the synergy effect between Cu and Ni. At last, the photocatalytic hydrogen evolution was studied as a function of content of Cu-Ni bimetallic deposit, molar ratio of Cu to Ni, hydrothermal reaction temperature, hydrothermal reaction time, pH, dosage of photocatalyst and concentration of sacrificial reagent, respectively. (C) 2014 Elsevier B.V. All rights reserved.