Therefore, the efficiency of water splitting is improved further. It is worth noting that no H2 was detected for ZnS photocatalyst because its bandgap is too large to absorb the visible light. Figure 6 Photocatalytic H 2 evolution of the obtained Cd 1−x Zn x S photocatalysts. (curve a) Cd0.98S, (curve b) Cd0.9Zn0.1S, (curve c) Cd0.72Zn0.26S, and (curve d) Cd0.24Zn0.75S. Conclusions We reported highly efficient three-dimensional Cd1−x Zn x S photocatalysts synthesized via one-step solvothermal pathway for photocatalytic H2 evolution under the irradiation of visible light. The Raman
spectrum DAPT implied the obtained Cd1−x Zn x S had good crystallinity and ordered structure. The XPS demonstrated that sulfur existed as a sulfur ion, while Cd and Zn are in 3d and 2p state, respectively. The bandgap of the synthesized Cd1−x Zn x S varied from 2.37 to 2.86 eV, which were suitable for the absorption of visible light. The photocatalytic activity of the obtained Cd1−x Zn x S photocatalysts were improved markedly compared with that of the sole CdS. This can be attributed to their appropriate bandgap and
position of the conduction band that is beneficial for visible light PRIMA-1MET mw absorption and photo-generated electron-hole pair separation, as well as 3D structure that offered a larger surface area, thus buy EX 527 supplying more surface reaction sites and better charge transport environment. Acknowledgements out This work was supported by the National Major Basic Research Project of 2012CB934302, National 863 Program 2011AA050518, the Natural Science Foundation of China (grant nos.11174197 and 61234005). References 1. Marban G, Valdes-Solis T: Towards the hydrogen economy? Int J Hydrogen Energy 2007, 12:1625–1637.CrossRef 2. Winter CJ: Hydrogen energy-abundant, efficient, clean: a debate over the energy-system-of change. Int. J Hydrogen Energy 2009, 34:S1-S52.CrossRef 3. Lewis NS: Toward cost-effective solar energy issue. Science 2007, 315:798–801.CrossRef 4. Andrews J, Shabani B: Re-envisioning the role of hydrogen in a sustainable energy economy. In.t J Hydrogen Energy 2012, 37:1184–1203.CrossRef
5. Fujishima A, Honda K: Electrochemical photolysis of water at a semiconductor electrode. Nature 1972, 238:37–38.CrossRef 6. Bolton JR, Strickler SJ, Connolly JS: Limiting and realizable efficiencies of solar photolysis of water. Nature 1985, 316:495–500.CrossRef 7. Rajeshwar K: Hydrogen generation at irradiated oxide semiconductor-solution interfaces. J Appl Electrochem 2007, 37:765–787.CrossRef 8. Ohtani B: Photocatalysis A to Z-what we know and what we do not know in a scientific sense. J Photochem. and Photobio. C: Photochem Rev 2010, 11:157–178.CrossRef 9. Foley JM, Price MJ, Feldblyum JI, Maldonado S: Analysis of operation of thin nanowire photoelectrodes for solar energy conversion. Energy Environ Sci 2012, 5:5203–5220.CrossRef 10.