Thermally stable electro catalytic nickel-phosphide film deposition on graphite for HER electrode application

Deposition of nickel phosphide film is crucial in electronic fabrication industries as well as a hydrogen generating energy material. Accordingly, the film adhesion on various substrates like insulators (Al2O3, SiO2, etc.) or conductors (glassy carbon, graphite, transparent conductors-FTO etc.) is highly important, specially for printed circuit boards. It has technologically important properties wrt. high temperature thermally stablity, anti-corrosion, large wear resistance, and competitive over-potential wrt Pt metal (for fuel cell). We tackeled the challenge of depositing an adherent nickel phosphide (Ni-P) film on the graphite (GR) substrate by using economic electroless (EL) technique. Firstly, the GR surface was activated by thermal treatment of GR under O-2 atmospheres, and obtained activated GR. Secondly, the EL precursor concentration was varied in the range of 0.1-0.2 M, to study its effect on Ni:P stoichiometry, structural phase and film thickness of Ni-P film on activated GR. Unlike on as recieved GR, activated GR showed film deposition due to the possible diffusion of O-2 over the top layers of GR surface, during activation process. Such O-2 diffusion led to an increased inter-planar distance & thus rendered favourable catalytic sites for Ni & P ions during EL deposition. This yeilds an adherent film of Ni3P phase after thermal treament, which is known to be themally stable beyond 1000 degrees C. Ni-P/GR film shows high potential application in (i) HER (hydrogen evolution reaction) for electro catalytic energy generation, and in (ii) graphite boat usable under elevated temperatures.

Automated summary

Deposition of adherent nickel phosphide film on graphite substrate using economic electroless technique is studied. The activation of graphite surface under O2 atmosphere promotes film deposition and results in an adherent Ni3P film which is thermally stable beyond 1000 degrees C. The Ni-P/GR film shows potential applications in hydrogen evolution reaction (HER) for electrocatalytic energy generation and as a graphite boat usable under elevated temperatures.