Structural and corrosion resistance properties of sputtered zirconium nitride thin films as electrode material for supercapacitor

•ZrN thin films were prepared by radio-frequency magnetron sputtering under various nitrogen partial pressure ratios.•ZrN0.4 exhibits excellent anti-corrosion property in 0.5 M Na2SO4 aqueous solution.•The excellent corrosion resistance attributes to a lower density of pin-hole defects and the dense passive layer of ZrO2. [Display omitted] In this paper, the surface morphology, crystal structure and corrosion resistance of the magnetron sputtered zirconium nitride (ZrN) thin films were evaluated and investigated. The results show that the surface of the prepared films is homogeneous and dense, and the root-mean-square surface roughness (Rq) are 21.0 nm (ZrN0.45), 1.8 nm (ZrN0.4), and 2.0 nm (ZrN0.35), respectively. With the increase of nitrogen partial pressure, the content of Zr3N4 in the ZrN films increased gradually. Potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) measurements demonstrate that all samples enhance the corrosion performance of ZrN-coated 304 SS. ZrN0.4 possesses a best corrosion resistance in 0.5 M Na2SO4 solution, which maintains complete and dense surface morphologies after 50 h immersion. The underlying related corrosion mechanism was explored and discussed, and the excellent corrosion resistance of ZrN0.4 film on 304 SS can be ascribed to a lower density of pin-hole defects and the dense passive layer of ZrO2.