Smartlab9kw diffraction system

Scanning electron microscopy (SEM) images were taken with an FEI Apreo S LoVac scanning electron microscope. Transmission electron microscopy (TEM) images were obtained with a JEOL-2100F system equipped with EDAX Genesis XM2. The in situ X-ray diffraction (XRD) measurements were performed on a Rigaku Smartlab9KW Diffraction System using monochromated Cu Kα radiation. X-ray photoelectron spectrum (XPS) measurements were determined by a photoelectron spectrometer using Al Kα radiation as the excitation source (PHI 5000 VersaProbe). All the peaks were calibrated with the C 1 s spectrum at a binding energy of 284.8 eV. In situ Raman spectrum measurements were performed on a Renishaw inVia reflex under excitation with 532 nm laser light. The NMR spectra were recorded on Varian Mercury Plus 400 instruments at 400 MHz (¹H NMR) and 101 MHz (¹³C NMR). Chemical shifts were reported in parts per million (ppm) downfield from internal tetramethylsilane. Multiplicity was indicated as follows: s (singlet), d (doublet), t (triplet). Coupling constants were reported in hertz (Hz). Gas chromatography‒mass spectrometry (GC‒MS) was carried out with a TRACE DSQ. The ultraviolet‒visible (UV‒Vis) absorbance spectra were measured on a Beijing Purkinje General T6 new century spectrophotometer.

The in situ electrochemical XRD pattern were measured at a Rigaku Smartlab9KW Diffraction System using a Cu Kα source (λ = 0.15406 nm). The electrolytic cell was homemade by Teflon with Pt wire as the counter-electrode and Hg/HgO electrode as the reference electrode. The pattern was collected in the 2θ ranging from 40.5° to 60.5° under the applied potential from without bias to −1.3 V vs. Hg/HgO. Each diffraction pattern was collected for 5 min for statistics.