Jem 2100 microscopy

The X-ray diffraction (XRD) patterns for the samples were obtained using a Bruker D8 Advance diffractometer with Cu-Kα (λ = 1.5405 Å) radiation source (40 kV, 40 mA). Transmission Electron Microscopy (TEM, JEOL, Tokyo, Japan) was carried out with a JEOL JEM-2100 microscopy (JEOL, Tokyo, Japan) operating at 200 kV with a nominal resolution, and high-resolution scanning transmission electron microscopy (HRTEM, JEOL, Tokyo, Japan) was performed on JEOL ARM200F. The composition of the prepared catalysts was measured using an inductively coupled plasma atomic emission spectrometer (ICP-AES, PerkinElmer, Waltham, MA, USA) on an IRIS Intrepid spectrometer after the dissolution of the samples in aqua regia.

Scanning electron microscopy (SEM) images were observed on a ZEISS Sigma 300 microscope, operated at 3 kV, 20 C. Prior to the SEM observations, all the samples were coated with a thin layer of gold using the Oxford Quorum SC7620 plasma sputtering apparatus. Transmission electron microscopy (TEM) images were observed on a JEOL JEM-2100 microscopy, operated at 200 kV, 20 C. Fourier transformation infrared (FTIR) spectra were obtained on an AV ATAR 370 Thermo Nicolet spectrophotometer from 600 to 4000 cm⁻¹ using KBr pellets. The X-ray diffraction (XRD) patterns were recorded on a Rigaku Ultima IV diffractometer using CuKα radiation (λ = 0.154 nm), operated at 40 kV and 40 mA with scan angle from 2θ = 5–80° at a scan rate of 10° min⁻¹. Ultraviolet-visible light (UV-vis) spectra were recorded on a Shimadzu UV-2450 spectrophotometer by using a quartz cuvette with an optical path length of 1 cm at room temperature. Thermogravimetric (TGA) curves were obtained on a NETZSCH STA 2500 simultaneous thermal analyzer under nitrogen atmosphere from 25 to 800 C with a heating rate of 10 C min⁻¹. The Zeta potentials (ζ) were measured by using a MALVERN ZETASIZER NANO ZS90 instrument at 25 C, the individual potential was measured for three times for accuracy.