Hybrid colloidal Au-CdSe pentapod heterostructures synthesis and their photocatalytic properties

ACS Appl Mater Interfaces. 2012 Nov;4(11):6266-72. doi: 10.1021/am301859b. Epub 2012 Nov 6.

Abstract

In this report, we present a self-driven chemical process to design exclusive Au/CdSe pentapod heterostructures with Au core and CdSe arms. We have analyzed these heterostructures using high-resolution transmission electron microscope (HRTEM), high angle annular dark field-scanning transmission electron microscopic (HAADF-STEM), X-ray diffraction, and X-ray photoelectron spectroscopy (XPS) studies. Microscopic studies suggest that pentapod arms of CdSe are nucleated on the (111) facets of Au and linearly grown only along the [001] direction. From the XPS study, the shifting of peak positions in the higher binding energy region for Au/CdSe heterostructures compared to Au nanoparticles has been found which indicates the charge transfer from CdSe to Au in heterostructures. The steady state and time resolved spectroscopic studies unambiguously confirm the electron transfer from photoexcited CdSe to Au, and the rate of electron transfer is found to be 3.58×10⁸ s⁻¹. It is interesting to note that 87.2% of R6G dye is degraded by the Au/CdSe heterostructures after 150 min UV irradiation, and the apparent rate constant for Au/CdSe heterostructures is found to be 0.013 min⁻¹. This new class of metal-semiconductor heterostructures opens up new possibilities in photocatalytic, solar energy conversion, photovoltaic, and other new emerging applications.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cadmium Compounds / chemistry*
  • Cadmium Compounds / radiation effects
  • Catalysis
  • Colloids / chemistry
  • Colloids / radiation effects
  • Coloring Agents / chemistry*
  • Coloring Agents / isolation & purification*
  • Crystallization / methods*
  • Gold / chemistry*
  • Gold / radiation effects
  • Light
  • Materials Testing
  • Metal Nanoparticles / chemistry*
  • Metal Nanoparticles / radiation effects
  • Metal Nanoparticles / ultrastructure
  • Selenium Compounds / chemistry*
  • Selenium Compounds / radiation effects

Substances

  • Cadmium Compounds
  • Colloids
  • Coloring Agents
  • Selenium Compounds
  • Gold
  • cadmium selenide