Electrochemical Water Splitting Using NiO-NiFe2O4/MWCNTs Nanocomposite as Electrocatalyst

Abstract

Escalating energy demands, scarcity of conventional energy resources and environmental concerns are the key to fuel production through water splitting. Various electrocatalysts have been reported, considering the cost effectiveness, stability and OER (oxygen evolution reaction) activity. In the same context, porous hybrid NiO-NiFe2O4/MWCNTs based nanocomposite as an OER electrocatalyst, has been investigated in the current study. The synthesis has been accomplished via co-precipitation using Tween as a surfactant. Characterization and electrochemical study for water electrolysis using synthesized electrocatalyst deposited glassy Carbon (GC) electrode as anode was carried out using relevant tools. Iron-doped Nickel oxide nanoparticles were synthesized recognizing excellent oxygen evolution activity of NiO and its increase in conductivity with Fe incorporation due to its higher electropositivity. Nanocomposites were synthesized by incorporating upto 20% weight percent MWCNT (Multiwall carbon nanotubes). High surface to volume ratios, stability and excellent conductivity of MWCNTs furthermore, reduction of crystallite sized due to their incorporation enhanced the performance of the electrocatalyst significantly. Hybrid formation of NiO and NiFe2O4 at a certain calcination temperature was also found to be the reason for enhanced OER activity due to the increased grain boundaries. Porous NiO-NiFe2O4/MWCNTs with 10% MWCNTs concentration outperformed with 35mA/cm2 of current density at 1.8V in alkaline media.