X-ray photoelectron spectroscopy (XPS) measurements and ultraviolet photoelectron spectroscopic (UPS) were conducted by Thermo ESCALAB 250XI at Shiyanjia lab (www.Shiyanjia.com).
The authors thank Ning Wang, Lu Huang, and daxia Xia from Shiyanjia Lab (www. Shiyanjia.com) for the Raman measurement and the simulation of the vibrational modes.
The authors thank Ning Wang, Lu Huang, and daxia Xia from Shiyanjia Lab (www. Shiyanjia.com) for the Raman measurement and the simulation of the vibrational modes.