3D CVD Graphene Oxide on Ni Foam towards Hydrogen Evolution Reaction in Acid Electrolytes at Different Concentrations

Abstract

Thin layers of graphene and graphene oxide coated on nickel foam substrate was synthesized by a chemical vapor deposition method and used as a hydrogen evolution reaction (HER) catalyst in acidic condition. The graphene oxide carbocatalyst with oxygen functional groups, large amounts of active sites, and hydrophilic property exhibits superior HER activity as compared to the pristine nickel foam and graphene. The graphene oxide coated on nickel substrate exhibits an overpotential of -83.2 mV vs. RHE at a current density of 10 mA cm -2 and an excellent electrochemical stability up to 7 hours in 1.0 M H 2 SO 4 . In addition, the effect of electrolyte concentrations was also studied in 0.1, 0.5, 1.0, and 2.0 M H 2 SO 4 . At high concentration, the HER activity is higher because large amounts of protons can increase the ionic conductivity in the electrolyte and can participate in the reaction generating more hydrogen when compared to the lower concentration. We believe that the graphene oxide-coated Ni electrode, which can be operated in an acidic environment, can be practically used as an alternative electrocatalyst towards HER.

Antibacterial effect of graphene oxide (GO) nano-particles against Pseudomonas putida biofilm of variable age

“…The double bonds between carbons C=C are shown at 284.6 eV while the carbon peaks at 286.7 and 288.3 eV represent C=O and O–C=O, respectively. These assignments agree with reference (Cheng et al 2013; Sarawutanukul et al 2018). The C=O groups mainly arise from ketones which are present on edges of GO sheets but may also be bound to the sheets as carbonyl groups (Song et al 2014) were the highest on the GO surfaces followed by C=C.…”

“…The C=O groups mainly arise from ketones which are present on edges of GO sheets but may also be bound to the sheets as carbonyl groups (Song et al 2014) were the highest on the GO surfaces followed by C=C. The C=O group derived from the epoxy (–O–) group on the surface due to the attachment of oxygen from water molecules (Sarawutanukul et al 2018). Results show that GO samples have organic compounds with multiple functional groups.…”

2D Layered Manganese Oxide Nanosheets as a Bifunctional Electrocatalyst for Zn-Air Batteries

“…Manganese (II) nitrate tetrahydrate (Mn(NO3)2•4H2O, 98%, Loba Chemie), potassium hydroxide (KOH, Ajax Finechem), zinc acetate ((CH3CO2)2Zn, 99.99%, Merck), hydrogen peroxide (H2O2, 30%, Chem-supply), N-Methyl-2-pyrrolidone (NMP, 99.5%, Qrec), Polyvinylidene fluoride (PVDF, Mw~534,000, Aldrich), and carbon black (TIMCAL) are analytical grade. Ni foam is used as a substrate (34) and carbon fiber paper (35) (CFP, SGL Carbon SE in Germany) is used as a gas diffusion layer for Zn-air battery. Glass microfiber filters (Whatman, GF/F) was used as a separator.…”

2D Layered Manganese Oxide Nanosheets as a Bifunctional Electrocatalyst for Zn-Air Batteries

“…Manganese (II) nitrate tetrahydrate (Mn(NO3)2·4H2O, 98%, Loba Chemie), potassium hydroxide (KOH, Ajax Finechem), zinc acetate ((CH3CO2)2Zn, 99.99%, Merck), hydrogen peroxide (H2O2, 30%, Chem-supply), N-Methyl-2-pyrrolidone (NMP, 99.5%, Qrec), Polyvinylidene fluoride (PVDF, Mw~534,000, Aldrich), and carbon black (TIMCAL) are analytical grade. Ni foam is used as a substrate (34) and carbon fiber paper(35) (CFP, SGL Carbon SE in Germany) is used as a gas diffusion layer for Zn-air battery. Glass microfiber filters (Whatman, GF/F) was used as a separator.…”