Improved kinetics of reduction of alkaline water on the g-CN-supported transition metal oxide/boride hetero-interface: A case study

The presence of multiple active sites and hetero-junction on a multi-component hetero-structured catalyst would exhibit modest hydrogen binding strength and charge transfer, as well as redistribution during interaction with the intermediates during the water reduction process. In this study, we synthesized a ternary iron oxide/nickel boride/graphitic carbon nitride (Fe3O4/NixB/g-CN) composite as the electrode material for the reduction of water under alkaline environment. Preformed NixB seed and Fe3O4 phases were codeposited on a g-CN layer. Post-catalytic characterization studies indicated facet selective reactive sites for NixB and Fe3O4 during the reduction of water. The composite required 130 mV overpotential for 10 mA cm(-2) current density. The Tafel slope value of 99 mV dec(-1) indicated that the adsorption step might determine the rate of reaction. The long-term chronoamperometric study showed almost unaltered current density over similar to 50 h at 150 mV, only similar to 7.0% current loss over 50 h. The reactivity and stability can be attributed to the synergistic interaction within metal centers and the carbon support with a large surface area.

Automated summary

In this study, a ternary composite material was synthesized as an electrode material for water reduction under alkaline conditions. The study showed that the material has selective reactive sites, requires a significant overpotential to achieve the desired current density, and exhibits good reaction rate and stability.