One-Pot Synthesis of Au Embedded ZnO Nanorods Composite Heterostructures with Excellent Photocatalytic Properties

Here, we have designed a noble composite nanostructure by embedding gold (Au) nanoparticles into zinc oxide (ZnO) nanorods surface in one pot synthesis as a photocatalyst. The formation the composite nanostructure was confirmed by X-ray diffraction, X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy and transmission electron microscopy investigations. Microscopic studies suggest that spherical Au nanoparticles are nucleated on the ZnO nanorods surface. XPS shows shifting of peak positions towards higher binding energy which indicates charge transfer from ZnO to Au in the composite nanostructures. This is unambiguously confirmed by the steady state spectroscopic studies. It was found that 95.7% (1.8 × 10⁻⁵ mM) of Methylene blue dye is degraded by the composite nanostructure after 140 min under UV light illumination and the apparent rate constant was found to be 0.015 min⁻¹. This new class of Au nanoparticles embedded ZnO nanorods composite nanostructure opens up new possibilities in photocatalytic, solar energy conversion, photovoltaic, and other new emerging applications.