Asap 2020 volumetric adsorption analyzer

The phases of obtained products were investigated by powder X-ray diffraction patterns (XRD) on a Bruker D8 Advance diffractometer using Cu-Kα radiation. The elemental composition was determined using inductively coupled plasma spectrometer (ICP, Optima 8300). Scanning electron microscopy (SEM, Hitachi SU8020) and transmission electron micrograph (TEM, FEI Talos F200X-G2) were adopted to investigate the morphologies of samples. The ASAP 2020 volumetric adsorption analyzer was used to measure the nitrogen adsorption-desorption isotherms at 77 K to analyze the specific surface area and average pore volume of the samples. Ultraviolet-visible diffuse reflectance spectroscopy was collected on Shimadzu UV2550 spectrophotometer. The X-ray photoelectron spectroscopy (XPS) spectrum was obtained by an ESCALAB250 X-ray photoelectron spectrometer to reveal the element composition and chemical state of the samples. All XPS peaks of the elements were calibrated against the C 1s line fixed at 284.6 eV as a reference. The ²⁷Al high-resolution NMR spectra were obtained at 750 MHz principal field on a Bruker AVANCE III equipped with high-speed MAS probe with 20 mg samples. Electron paramagnetic resonance spectroscopy (EPR) spectra were used to detect the photo-excited active species during photocatalytic reaction on a Bruker EMX spectrometer with 400 mg/L solution.

The surface topography characteristics were observed using field emission scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The high-angle annular dark-field (HAADF) element mapping and energy-dispersive X-ray spectroscopy (EDS) were collected using a scanning tunneling electron microscopy (Tecnai G2 F20, FEI). Brunauer–Emmett–Teller (BET) measurement was conducted by the N₂ adsorption/desorption analysis on an ASAP 2020 volumetric adsorption analyzer at 77 K. The X-ray diffraction (XRD) patterns were recorded on an XD-3 Purkinje diffractometer using Cu Kα radiation, and the scan rate was 5° min⁻¹ over the range of 2θ = 10–60°. X-ray photoelectron spectroscopy (XPS) analyses were carried out on a Kratos Axis Ultra DLD electron spectrometer to analyze chemical elements and chemical configuration, and the binding energy was calibrated by means of the C 1s peak energy of 284.8 eV.