Superhydrophobic Cobalt–Graphene Composite for the Corrosion Protection of Copper Bipolar Plates in Proton Exchange Membrane Fuel Cells

Abstract

Superhydrophobic cobalt and cobalt-graphene films were fabricated on copper bipolar plates using potentiostatic electrodeposition to improve their corrosion resistance and surface conductivity. A scanning electron microscope (SEM) was used to study the surface morphology of the prepared superhydrophobic films. The results show that the cobalt film modified by stearic acid (Co-SA) and cobalt-graphene composite modified by stearic acid, Co-G-SA, exhibit micro-nano structures. The results of the Fourier transforming infrared spectrophotometer (FTIR) confirm that the copper substrate was coated by Co-SA and Co-G-SA films. The wettability results of the prepared superhydrophobic films demonstrate that the films display superhydrophobicity, where the fabricated Co-SA and Co-G-SA films have contact angles of 159° and 165°, respectively. Chemical stability, mechanical abrasion resistance, surface conductivity, and corrosion resistance in a simulated proton exchange membrane fuel cells (PEMFC) environment are significantly higher for copper coated by Co-G-SA film. Because the copper coated with Co-G-SA has a low ICR value and a high corrosion resistance, it is thought to be a good choice for PEMFC bipolar plates.

Eco-friendly method for construction of superhydrophobic graphene-based coating on copper substrate and its corrosion resistance performance

“…The SHP surface manufacturing principles are based on natural phenomena, including lotus, rose, and rice leaves 1 , 2 . Because of its relevance, such as drag reduction 3 , corrosion resistance 4 , self-cleaning capabilities 5 , water/oil separation 6 , and so on, SHP surfaces have recently sparked significant interest in academic research and prospective industrial applications. Two elements must be present to construct a superhydrophobic surface: rough surface texture with a distinct binary structure and surface chemistry modification with a low-free-energy coating 7 .…”

Construction of superhydrophobic graphene-based coating on steel substrate and its ultraviolet durability and corrosion resistance properties

“…The quick synthesis of corrosion products on the electrode surface for bare steel or the formation of a passive layer when the steel is treated with a SHP coating prevents the establishment of a perfect anodic Tafel region 77 , 78 . The cathodic polarization plots exhibit a limiting current, which suggests that the diffusion of the oxygen gas controls the cathodic process from the electrode surface to the bulk 79 . The limiting diffusion currents in the cathodic polarization curves represent the reduction reaction of oxygen, Eq.…”

Fabrication of Superhydrophobic Surface on Anodized Aluminum Through a Wet-Chemical Route

“…Superhydrophobic surfaces (SHSs) with water contact angles (WCA) greater than 150°and a contact angle hysteresis less than 10°s how great promise for a range of applications such as anti-icing, [1][2][3] self-cleaning, 4 anti-corrosion, [4][5][6] oil-water separation [7][8][9] and waterproof materials. 10 As of now, there are a great number of methods adopted for the fabrication of SHSs, such as chemical vapour deposition, 11 micro-arc oxidation, 12 sol-gel technique, 13 chemical etching , [14][15][16][17] solution-immersion method, 18 spin coating, 19 wetchemical grafting, 20,21 layer-by-layer self-assembly, 22,23 chemical and electrochemical deposition [24][25][26] and laser-ablation. 27,28 Physical adsorption of the constituents rendering the base material surface superhydrophobic is possible in dip-coating and spin-coating methods, but the surface fabricated may not have good mechanical stability.…”

“…20 Anodization in comparison with other surface treatment methods is one of the simple and efficient methods of protecting aluminum surfaces from corrosion and abrasion. 26 An anodized surface also serves as a base to fabricate self-assembled nanostructures. 25 Wet-chemical grafting allows the chemical bond formation between the surface metal atoms and the functionalizing molecules, providing the desired surface properties.…”