Green hydrogen generation in alkaline solution using electrodeposited Ni-Co-nano-graphene thin film cathode

Environ Sci Pollut Res Int. 2024 Apr;31(19):28719-28733. doi: 10.1007/s11356-024-32948-0. Epub 2024 Apr 1.

Abstract

Green hydrogen generation technologies are currently the most pressing worldwide issues, offering promising alternatives to existing fossil fuels that endanger the globe with growing global warming. The current research focuses on the creation of green hydrogen in alkaline electrolytes utilizing a Ni-Co-nano-graphene thin film cathode with a low overvoltage. The recommended conditions for creating the target cathode were studied by electrodepositing a thin Ni-Co-nano-graphene film in a glycinate bath over an iron surface coated with a thin copper interlayer. Using a scanning electron microscope (SEM) and energy-dispersive X-ray (EDX) mapping analysis, the obtained electrode is physically and chemically characterized. These tests confirm that Ni, Co, and nano-graphene are homogeneously dispersed, resulting in a lower electrolysis voltage in green hydrogen generation. Tafel plots obtained to analyze electrode stability revealed that the Ni-Co-nano-graphene cathode was directed to the noble direction, with the lowest corrosion rate. The Ni-Co-nano-graphene generated was used to generate green hydrogen in a 25% KOH solution. For the production of 1 kg of green hydrogen utilizing Ni-Co-nano-graphene electrode, the electrolysis efficiency was 95.6% with a power consumption of 52 kwt h-1, whereas it was 56.212. kwt h-1 for pure nickel thin film cathode and 54. kwt h-1 for nickel cobalt thin film cathode, respectively.

Keywords: Corrosion; Electrodeposition; Low power consumption; Ni-cobalt electrode; Transmission electron microscopy; Water electrolysis.

MeSH terms

  • Cobalt* / chemistry
  • Electrodes*
  • Electrolysis
  • Graphite* / chemistry
  • Hydrogen* / chemistry
  • Nickel* / chemistry

Substances

  • Graphite
  • Hydrogen
  • Nickel
  • Cobalt