Invia re04

Physical morphology and structure of catalysts were studied with scanning electron microscopy (SEM, HITACHI S-4700, Tokyo, Japan). X-ray diffraction (Rigaku, Tokyo, Japan) with Cu-Kα radiation was used to check the film crystallinity. The Raman spectral results were collected using an Ar laser (512 nm) (Renishaw inVia RE04, Gloucestershire, United Kingdom) with a scan speed of 30 s and 1 µm spot size. X-ray photoelectron spectroscopy (XPS, PHI 5000 Versa Probe (25 W Al Kα), Kanagawa, Japan) was used for the chemical compositions.

Field-emission scanning electron microscopy (FESEM) (HITACHI S-4700, Tokyo, Japan) was used to explore the morphological studies. The atomic structures were analyzed by a JEOL-2010F transmission electron microscopy (TEM) with an operation voltage of 200 keV. The Raman spectroscopy (Renishaw inVia RE04, Gloucestershire, UK) measurements were performed in ambient conditions, using the 512 nm Ar laser source with a laser spot size of 1 µm and a scan speed of 30 s. The structural properties were characterized by Rigaku X-ray diffractometer (XRD) (Tokyo, Japan) with Cu-K_α radiation (0.154 nm), at 40 kV and 40 mA, in the scanning range of 10–80° (2θ). For chemical composition and binding energy, the X-ray photoelectron spectroscopy (XPS) measurements were carried out by using an Ulvac PHI X-tool spectrometer (Kanagawa, Japan) with Al K_α X-ray radiation (1486.6 eV). A Brunauer–Emmet–Teller (BET) study to calibrate the surface area of nanostructures was performed, using a N₂ adsorption/desorption medium at 77 K (Micromeritics, Norcross, GA, USA). Pore size distribution was measured with the Barrett–Joyner–Halenda (BJH) analysis.