Studies on Co3O4-NiO nanocomposites for potential electrocatalyst for alkaline water electrolysis

Investigation of potential electrocatalysts to produce hydrogen and oxygen from water electrolysis is of fundamental and technological importance. In this regard, herein, Co3O4-NiO nanocomposite with compositions 0.9Co(3)O(4)-0.1NiO, 0.8Co(3)O(4)-0.2NiO, 0.7Co(3)O(4)-0.3NiO and 0.6Co(3)O(4)-0.4NiO, has been identified as electrocatalysts for oxygen evolution reaction (OER). A facile wet chemical citrate-nitrate decomposition protocol has been proposed to synthesize Co3O4-NiO electrocatalysts in large scale. The systematic electrochemical studies have been carried out to understand the effect of NiO addition on the OER performance of Co3O4. The 0.7Co(3)O(4)-0.3NiO nanocomposite modified screen-printed electrode (SPE) exhibits superior OER activity as compared to the other Co3O4-NiO nanocomposites and pristine Co3O4 modified SPE. The 0.7Co(3)O(4)-0.3NiO modified SPE delivers the current density of 10 mA cm(-2) at lowest overpotentials of 280 mV with smallest Tafel slope of 55 mV dec(-1) and long term stability of 25 h in 1.0 M KOH. This study demonstrates the Co3O4-NiO nanocomposite performs better for the catalysis OER than Ni-doped Co3O4.

Automated summary

This study identified Co3O4-NiO nanocomposite as an efficient electrocatalyst for oxygen evolution reaction (OER) and proposed a simple synthesis method for large-scale production. The 0.7Co(3)O(4)-0.3NiO modified electrode showed superior OER activity with lowest overpotentials, smallest Tafel slope, and long term stability compared to other compositions. This research demonstrates the superior performance of Co3O4-NiO nanocomposite over Ni-doped Co3O4 for OER catalysis.