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Updated: Jul 20, 2025
Harvesting Solar Energy by Means of Charge-Separating Nanocrystals and Their Solids
Published on: August 23, 2012
Size transformation of Au nanoclusters for enhanced photocatalytic hydrogen generation: Interaction behavior at
Xiao-He Liu1, Yi He2, Zhi Li2
1Department of Environmental Engineering, College of Geology and Environment, Xi'an University of Science and Technology, Xi'an 710054, China; Department of Environmental Science and Engineering, State Key Laboratory of Multiphase Flow in Power Engineering, School of Energy and Power Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi 710049, China.
Abstract:
Recently, atomically precise metal nanoclusters (NCs) become a new class of photosensitizer for light energy conversion in metal-cluster-sensitized semiconductor (MCSS) system. However, fundamental understanding for the suitable combination of NCs and semiconductor is still unclear. Aside from aspects of light harvesting, energy level alignment and catalytic activity, interfacial interaction behavior at NCs/semiconductor interface is also crucial due to its important influence in charge transportation. In this work, the interface interaction between Au NCs and TiO2 is examined by precise transformation of Au NCs from Au22(SG)18 to Au18(SG)14, as well as its effect on photocatalytic hydrogen production activity. From the optical, charge transport and solid-states spectroscopy analyses, it is able to display that precisely tuning the number of core atoms from Au22(SG)18 to Au18(SG)14 results in the strong interface interaction between Au NCs and TiO2, reflecting in high difference of work function and modified surface band bending of TiO2, therefore promoting the injection of electrons from NCs to TiO2 and reducing interfacial charges recombination. As a result, Au18(SG)14/TiO2 shows higher hydrogen generation rate than Au22(SG)18/TiO2 under light irradiation. This work would provide new insights into rational combination of metal NCs with semiconductor and highlights the overlooked effect of interfacial interaction behavior on light energy conversion.
