02820nas a2200253 4500008004100000022001400041245010600055210006900161260000800230300001600238490000700254520197500261653001202236653001902248653003002267653000902297653002002306100001602326700002102342700002202363700002002385700003002405856013102435 2019 eng d a1944-824400aElectronic integration and thin film aspects of Au-Pd/rGO/TiO2 for improved solar hydrogen generation0 aElectronic integration and thin film aspects of AuPdrGOTiO2 for cSEP a32869-328780 v113 a
In the present work, we have synthesized noble bimetallic nanoparticles (Au-Pd NPs) on a carbon-based support and integrated with titania to obtain Au-Pd/C/TiO2 and Au-Pd/rGO/TiO2 nanocomposites using an ecofriendly hydrothermal method. Here, a 1:1 (w/w) Au-Pd bimetallic composition was dispersed on (a) high-surface-area (3000 m(2) g(-1)) activated carbon (Au-Pd/C), prepared from a locally available plant source (in Assam, India), and (b) reduced graphene oxide (rGO) (Au-Pd/rGO); subsequently, they were integrated with TiO2. The shift observed in Raman spectroscopy demonstrates the electronic integration of the bimetal with titania. The photocatalytic activity of the above materials for the hydrogen evolution reaction was studied under 1 sun conditions using methanol as a sacrificial agent in a powder form. The photocatalysts were also employed to prepare a thin film by the drop-casting method. Au-Pd/rGO/TiO2 exhibits 43 times higher hydrogen (H-2) yield in the thin film form (21.50 mmol h(-1) g(-1)) compared to the powder form (0.50 mmol h(-1) g(-1)). On the other hand, Au-Pd/C/TiO2 shows 13 times higher hydrogen (H-2) yield in the thin film form (6.42 mmol h(-1) g(-1)) compared to the powder form (0.48 mmol h(-1) g(-1)). While powder forms of both catalysts show comparable activity, the Au-Pd/rGO/TiO2 thin film shows 3.4 times higher activity than that of Au-Pd/C/TiO2. This can be ascribed to (a) an effective separation of photogenerated electron-hole pairs at the interface of Au-Pd/rGO/TiO2 and (b) the better field effect due to plasmon resonance of the bimetal in the thin film form. The catalytic influence of the carbon-based support is highly pronounced due to synergistic binding interaction of bimetallic nanoparticles. Further, a large amount of hydrogen evolution in the film form with both catalysts (Au-Pd/C/TiO2 and Au-Pd/rGO/TiO2) reiterates that charge utilization should be better compared to that in powder catalysts.
10abimetal10aPhotocatalysis10asurface plasmon resonance10aTiO210awater splitting1 aTudu, Bijoy1 aNalajala, Naresh1 aReddy, Kasala, P.1 aSaikia, Pranjal1 aGopinath, Chinnakonda, S. uhttp://library.ncl.res.in/content/electronic-integration-and-thin-film-aspects-au-pdrgotio2-improved-solar-hydrogen-generation