Inter-Electronic Interaction between Ni and Mo in Electrodeposited Ni-Mo-P on 3D Copper Foam Enables Hydrogen Evolution Reaction at Low Overpotential.

Electrocatalytic hydrogen evolution reaction (HER) via water electrolysis has been considered the most effective and sustainable route to produce clean hydrogen. Designing and structure optimization are the two important parameters to develop an affordable, easy to fabricate, and stable non-noble metal electrocatalyst for the production of hydrogen as a clean, sustainable, and green fuel. Herein, we have synthesized Ni-Mo-P on copper foam (Cuf) via a facile single-step electrodeposition method, which can show stratospheric efficiency toward HER with a Tafel slope of 67 mV dec-1 and a very low overpotential of only 53 mV at a current density of 20 mA cm-2. Cuf acts as a conducting substrate support and the existence of the inter-electronic effect between Ni and Mo results in substantial catalytic activity toward hydrogen generation. In addition to this, the catalyst shows long time stability of around 97.5 h with almost negligible degradation under the applied overpotential for HER in alkaline media. This work features the significance of structure design and construction of non-noble metal catalysts via a simple method for efficient hydrogen generation.

Tuning the Electronic Structure of Cobalt Selenide on Copper Foam by Introducing a Ni Buffer Layer for Highly Efficient Electrochemical Water Splitting.

The development of a cost-effective, remarkably competent, and durable bifunctional electrocatalyst is the foremost requirement of water splitting to generate H2 fuel as a renewable energy technology. Three-dimensional porous copper foam (Cuf) when electrochemically decorated with transition metal selenide results in a highly active electrocatalyst for adequate water electrolysis. In terms of water splitting, the role of cobalt selenide and Cuf has already proven to be remarkable. The introduction of a Ni buffer layer between Cuf and cobalt selenide (Cuf@Ni-CoSe2) acts as a valve to enhance the electron thrust from the substrate to the material surface with no compromise in the overall material conductivity, which not only increases the efficiency and activity but also improves the stability of the catalyst. The self-supported synthesized catalyst material showed an admirable activity toward the oxygen evolution reaction and hydrogen evolution reaction in alkaline media. The performance of the catalyst was found to be significantly better than that of the noble catalyst RuO2. The catalyst was very stable up to 93 h and attained a full cell voltage of only 1.52 V at a current density of 10 mA cm-2. Therefore, for large-scale hydrogen production, this as-synthesized catalyst hss the potential to replace conventional fossil fuel-based energy systems.