Tecnai g2 f20 s twin d573

The morphologies of the samples were observed by a JSM-6700F electron microscope (JEOL, Japan) with an acceleration voltage of 30 kV. The FTIR spectrums of the samples were surveyed using Nicolet 5700 FTIR spectrometer with a resolution of 4 cm⁻¹ through KBr method. Raman spectra were measured on InVia Raman Microscope. Excitation was by means of the 488 nm line of an argon ion laser with an output power in the range of 200 to 300 mw. The instrument is equipped with a microscope with a focal spot size in the range of a few micrometers. The adsorption-desorption isotherms of nitrogen were measured at 77 K by using a Micromeritics ASAP 2420 analyzer. The EDS spectra (JEOL JSM-6700F, Japan) were also used to analyze the composition of the samples. XPS spectrum was collected on a Thermo ESCALAB 250. The morphology and structure of the samples were analyzed by TEM using a FEI Tecnai G2 F20 s-twin D573 operated at 200 kV.

Thermogravimetric analyses (TGA) were performed using a Netzch Sta 449c thermal analyzer system at the heating rate of 5 °C min⁻¹ in N₂ atmosphere. CHN elemental analyses were collected using an Elementar model Vario Micro analyzer. The Fourier transform infrared (FT-IR) spectra were recorded using a Nicolet Impact 410 Fourier transform infrared spectrometer. The N₂ adsorption isotherms were measured on a Micromeritics ASAP 2020 surface area and porosity analyzer. The powder X-ray diffraction (PXRD) spectra were collected using a Rigaku D/MAX2550 diffractometer with Cu Kα radiation (λ = 1.54178 Å). Transmission electron microscopy (TEM) images and high-resolution transmission electron microscopy (HR-TEM) images were recorded on a FEI Tecnai G2F20 s-twin D573 with an acceleration voltage of 300 kV. Field-scanning electron microscopy (FE-SEM) images were obtained on a JEOLJXA-840 under an accelerating voltage of 15 kV. The solid-state ¹³C cross-polarization/magic-angle spinning nuclear magnetic resonance (CP/MAS NMR) spectra of JLUE-COPs were obtained at 5 kHz. The zeta potentials were measured at various pH values with a JS94H (Shanghai, China).