Nova nanosem 450

The morphologies and microstructures of the samples were examined using scanning electron microscope (SEM, FEI Nova NanoSEM 450) and transmission electron microscopy (TEM, JEOL JEM-2100F). The pore structure was measured at 77 K using a Quadrasorb SI analyzer (Quantachrome Instrument Crop) and the corresponding pore size distribution was obtained by the density functional theory (DFT model). X-ray diffraction (XRD) measurements were recorded on a Rigaku D/max 2550 diffractometer using Cu Kα radiation. X-ray photoelectron spectroscopy (XPS) measurements were carried out on an Axis Ultra DLD spectrometer with Al Kα radiation. NH₃-temperature programmed desorption (NH₃-TPD) was performed on a TP-5080 adsorption analyzer (Xianquan Co.) with a thermal conductivity detector (TCD). Before the NH₃-TPD experiment, 0.1 g sample was pretreated in He flow at 300 °C for 30 min, followed by cooling down to 100 °C. Afterwards, the He flow was switched to a stream containing 5 vol% NH₃/He to adsorb NH₃ for 60 min at 100 °C and then purged with He at the same temperature. Finally, the temperature was increased to 800 °C in He flow at a heating rate of 10 °C min⁻¹.

Scanning electron microscopy (SEM) images were collected using either a Nova NanoSEM 450 or a JEOL 6701F electron microscope operating at an accelerating voltage of 10 kV. UV-vis spectra were obtained using a Lambda 750S spectrometer. Matrix-assisted laser desorption-ionization time-of flight (MALDI-TOF) mass spectra were recorded with a Biflex III (Bruker Daltonics Inc., Germany) mass spectrometer using 1,1,4,4-tetraphenyl-1,3-butadiene as matrix in a positive ion linear mode. Cyclic voltammogram (CV) and differential pulse voltammogram (DPV) were measured in 1,2-dichlorobenzene (o-DCB) with 0.1 M of (n-Bu)₄NPF₆ as supporting electrolyte at a Pt working electrode with a CHI660E workstation.