A Comparative Study of Copper-doped and Copper, Nitrogen Co-doped DLC Film Electrode and Its Electrochemical Properties

摘要

Copper (Cu), Nitrogen (N) Co-doped diamond-like carbon ((Cu:N)-DLC) films and Cu doped DLC (Cu-DLC) films were fabricated by high power impulse magnetron sputtering technique (HiPIMS). The influence of copper and nitrogen incorporation on the microstructure and electrochemical properties of Cu-DLC and (Cu:N)-DLC films were investigated by X-ray photoelectron spectroscopy, raman spectra and electrochemical workstation. The surface of all the films is cauliflower-like clusters, no obvious large particle Cu clusters can be observed. XRD patterns of theses films have only diffraction peak of copper and no other compounds. Raman spectra illustrate that I-d/I-g varies from 2.79 to 3.01 as the N contents changes. XPS results identify that Cu does not form compounds or solid solution into DLC films. Electrochemical tests show that the electrode activity gradually increases with increasing the N contents of (Cu:N)-DLC electrode. Compared with (Cu:N)-DLC electrode, Cu-DLC electrode has a faster electron transfer rate (K-0 is 1.88 x 10(-2) cms(-1)), low transfer resistance (227.0 omega cm(2)), and a higher electrochemical activity (Delta Ep is 93 mV). Consequently, the electrochemical properties of Cu doped DLC films are better than that of Cu, N co-doped DLC films.