Improved corrosion resistance and biocompatibility of biodegradable magnesium alloy by coating graphite carbon nitride (g-C3N4)

In this study, one-step chemical vapor deposition method (OS-CVD) using urea as a precursor was used to deposit carbon nitride (g-C3N4) film on the magnesium alloy. The material composition and characteristic functional groups of the as-prepared films were characterized by using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), energy dispersive spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS). The surface morphology of the carbon nitride film on the magnesium alloy was observed by using a scanning electron microscope (SEM) and an atomic force microscope (AFM). The corrosion resistance of magnesium alloy was investigated via an electrochemical method and an immersion test. The biocompatibility and hemolysis rate of graphitic carbon nitride films were studied via in vitro cellular experiments and in vivo animal experiments. The results indicated that the corrosion resistance and biocompatibility of AZ31B Mg alloy was significantly improved by g-C3N4 coating.