Publication

Abstract : Catalytic electrode assisted water electrolysis is a potential method of clean hydrogen production. The present work deals with the surface modification of Ni-P electrode (NPE) by electroless co-deposition of cubic phased cobalt oxide, for enhanced hydrogen evolution from 1 M NaOH solution. The excellent coating thickness (9–10 µm), hardness (547 HVN) and wear resistant properties of 5 g/L Co3O4 deposited Ni-P divulge its appropriateness for industrial use. The co-operative interaction of cubic phased Co3O4 with Ni and P improves the interfacial charge transfer reaction (lower Rct of 66 Ω) and cause HER at a reduced overpotential (71 mV at 10 mA/cm2). The mild steel supported NPE/Co3O4 coating is highly porous and conductive. And the evolution of hydrogen from 1 M NaOH solution is kinetically controlled by Volmer process. The mechanism of entire catalyst assisted water splitting follows Volmer-Tafel route. The activity of the electrode was thoroughly evaluated. Furthermore the continuous evolution of hydrogen for a period of 50 h by the metal oxide modified NPE, reiterate the sustainability of electro activity. The implemented surface engineering strategy for Ni-P electrode by the spinel structured cubic phased Co3O4 co-deposition to get a rough and porous surface morphology is by a relatively less expensive electroless deposition method. The excellent value for electro catalytically active surface area (ECSA = 93.14 cm2) and long term activity in alkaline solution made NPE/5 g/L Co3O4, a competent catalytic electrode for HER.