摘要：Hydrogen evolution by electrocatalysis clean energy. However, it is challenging is an attractive method of supplying to find cheap and efficient alternatives to rare and expensive platinum based catalysts. Pt provides the best hydrogen evolution performance, because it optimally balances the free energies of adsorption and desorption. Appropriate control of these quantities is essential for producing an efficient electrocatalyst. We demonstrate, based on first principles calculations, a stepwise designed Rh-au-Si ternary catalyst, in which adsorption （the Volmer reaction） and desorption （the Heyrovsky reaction） take place on Rh and Si surfaces, respectively. The intermediate au surface plays a vital role by promoting hydrogen diffusion from the Rh to the Si surface. Theoretical predictions have been explored extensively and verified by experimental observations. The optimized catalyst （Rh-au-SiNW-2） has a com- position of 2.2：28.5：69.3 （Rh：au：Si mass ratio） and exhibits a Tafel slope of 24.0 ***-L Its electrocatalytic activity surpasses that of a commercial 40 wt.% Pt/C catalyst at overpotentials above 0.19 V by exhibiting a current density of greater than 108 mA-cm-2. At 0.3 V overpotential, the turnover frequency of Rh-au-SiNW-2 is 10.8 times greater than that of 40 wt.% Pt/C. These properties may open new directions in the stepwise design of highly efficient catalysts for the hydrogen evolution reaction （HER）.

摘要：The interfacial perimeter of gold nanocatalysts is popularly viewed as the active sites for a number of chemical reactions,while the geometrical structure of the interface at atomic scale is less ***,TiO2-nanosheets and nanospindles were adapted to accommodate au particles(~2.2 nm),forming au-TiO2{001}and au-TiO2{101}*** calcination at 623 K in air,HAADF-STEM images evidenced that the au particles on TiO2{101}enlarged to 3.1 nm and these on TiO2{001}remained unchanged,suggesting the stronger metal-support interaction on TiO2{001}.au/TiO2{001}was more active for CO oxidation than au/TiO2{101}system.

摘要：Novel CdSe quantum dot （QD）-sensitized au/TiO2 hybrid mesoporous films have been designed, fabricated, and evaluated for photoelectrochemical （PEC） applications. The au/TiO2 hybrid structures were made by assembly of au and TiO2 nanoparticles （NPs）. A chemical bath deposition method was applied to deposit CdSe QDs on TiO2 NP films with and without au NPs embedded. We observed significant enhancements in photocurrent for the film with au NPs, in the entire spectral region we studied （350-600 nm）. Incident-photon-to-current efficiency （IPCE） data revealed an average enhancement of 50%, and the enhancement was more significant at short wavelength. This substantially improved PEC performance is tentatively attributed to the increased light absorption of CdSe QDs due to light scattering by au NPs. Interestingly, without QD sensitization, the au NPs quenched the photocurrent of TiO2 films, due to the dominance of electron trapping over light scattering by au NPs. The results suggest that metal NPs are potentially useful for improving the photoresponse in PEC cells and possibly in other devices such as solar cells based on QD-sensitized metal oxide nanostructured films. This work demonstrates that metal NPs can serve as light scattering centers, besides functioning as photo-sensitizers and electron traps. The function of metal NPs in a particular nanocomposite film is strongly dependent on their structure and morphology.