Pd decorated MnO2 nanowalls were sputter deposited in a custom
made sputtering chamber (Excel Instruments) with a base
pressure of 2 × 10−6 Torr. Images were acquired with Carl Zeiss FESEM
(scanning electron microscope) using the secondary electron
detector. The room temperature X-ray diffraction (XRD) measurements
were carried out with CuK radiation using X-ray
diffractometer (Bruker AXS, D8 Advance) with (–2) geometry.
The chemical compositions were characterized by X-ray photoelectron
spectroscopy (XPS, Perkin Elmer model 1257), Ra