Preparation and corrosion resistance of graphite/titanium oxide composite coating

Abstract

Graphite/titanium oxide composite anti-corrosion coating was applied on the surface of aluminum alloy. The surface morphology and composition of the coating were analyzed by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The electrochemical properties of the coatings with different graphite additions were tested by potentiodynamic polarization curves and AC impedance. The coatings with five graphite content were prepared. The phases in the coatings are stable before and after corrosion, avoiding the volume change caused by structural transformation, so that these coatings have good adhesion and are not easy to fall off from the metal surface. As a filler, the graphite dispersed in the coatings extends the penetration path of the corrosive medium. The electrochemical analysis showed that the physical barrier effect of the coating was enhanced with the increase of graphite content, and the optimal addition amount was 2.5%. When the content of graphite exceeds this value, the barrier effect of the coating on the corrosion medium will be weakened due to particle agglomeration.

A g‐C3N4/PANI S‐scheme heterojunction with face‐to‐face structure to improve the anticorrosion property on Q235 steel and enhanced mechanism study

“…9,10 Herein, photocatalytic coating layers are the most suitable candidate to evade the drawbacks of coating protection method and sacrificial anode protection methods, combining the advantages of them to improve the anticorrosion performance of tradition coating layers. 11,12 Polyaniline (PANI), a typical conductive polymer, has been well investigated due to its easy synthesis, structural diversity, and good environmental stability, [13][14][15] which has been applied in corrosion resistance due to its excellent environmental sustainability, good permeability resistance, and outstanding chemical and photo stability. 13,14,16 Besides, the PANI coating layer is the most suitable substrate layer due to the electron conductivity and the density structure; the density structure can suppress the electrons migrated from substrate on surface layers and the electron conductivity can transfer the electron (generated from photocatalytic coating layers) from surface layer to substrate to suppress the corrosion of metals.…”

“…11,12 Polyaniline (PANI), a typical conductive polymer, has been well investigated due to its easy synthesis, structural diversity, and good environmental stability, [13][14][15] which has been applied in corrosion resistance due to its excellent environmental sustainability, good permeability resistance, and outstanding chemical and photo stability. 13,14,16 Besides, the PANI coating layer is the most suitable substrate layer due to the electron conductivity and the density structure; the density structure can suppress the electrons migrated from substrate on surface layers and the electron conductivity can transfer the electron (generated from photocatalytic coating layers) from surface layer to substrate to suppress the corrosion of metals. [17][18][19][20] Furthermore, the protonation of PANI electronically conductive is widely employed in the corrosion protection fields and promotes the passivation layer formation on the metal surface, maintaining the redox potential of substrate to further protect the substrate metals.…”