Controllably Alloyed, Low Density, Free-standing Ni-Co and Ni-Graphene Sponges for Electrocatalytic Water Splitting

• DOI: 10.1038/srep31202
• Publication Date: 2016-08-11T09:35:26Z
• Authors: Thazhe Veettil Vi...; Suhail Mubarak; Myung Gwan Hahm; V. Prabu; Subbiah Alwarappan; Tharangattu N. Na...
• Keywords: Oxygen evolution; Electrolysis of water

Abstract Synthesis of low cost, durable and efficient electrocatalysts that support oxygen evolution reaction (OER) hydrogen (HER) are the bottlenecks in water electrolysis. Here we propose a strategy for development controllably alloyed, porous, density nickel (Ni) cobalt (Co) based alloys - whose electrocatalytic properties can be tuned to make them multifunctional. Ni Co alloy with chemical structure 1 2 is identified as an OER catalyst among other stoichiometric structures terms over potential @ 10 mAcm −2 (1.629 V), stability, tafel slope (87.3 mV/dec), high Faradaic efficiency (92%), its performance also found on par benchmarked IrO . Tunability porous metal synthesis allowed incorporation graphene during sponge formation, Ni- incorporated nitrogen doped (Ni-NG) have very HER activity. A electrolysis cell fabricated demonstrated these freestanding electrodes stability (>10 hours) large current (10 1.6 opening new avenues design cost effective light weight energy devices.