Gold nanorods or nanoparticles deposited on layered manganese oxide: New findings

Herein we consider the role of gold nanorods, with a diameter of ∼ 10 nm or nanoparticles (size < 100 nm), deposited on nanolayered Mn oxide in water oxidation. The catalysts were synthesized by simple methods and characterized by scanning electron microscopy, energy dispersive spectrometry, high resolution transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and atomic absorption spectroscopy. In the next step, the water-oxidizing activities of these composites were studied in the presence of cerium(iv) ammonium nitrate as a non-oxo transfer oxidant. A comparison with other previously reported Mn oxides and important factors influencing the water-oxidation activities of Mn oxides are also discussed. Our results show that gold has no significant effect on the water-oxidizing activity of the Mn oxide phase at least in the presence of Ce(iv).