Dual-phase amorphous-nanocrystalline nanoporous sites activated in Mo inserted CuTi metallic glass as efficient electrocatalysts for hydrogen evolution reaction

The production of noble metal-free, high-performance, earth-abundant hydrogen evolution reaction (HER) electrocatalysts is a challenging search but indispensably a vital issue for green energy conversion and production. Herein, we report a nanoporous self-supported CuTiMo site nanostructured from Cu60Ti37Mo3 metallic glass as a highly efficient electrocatalyst for HER. The development of nanoporous structure from metallic glassy alloy rather than the conventional crystalline alloy is carried out, and a comprehensive plausible working mechanism of nanoporous structure development is outlined. The novelty of the present research is the nanostructuring of metallic glasses to form crystalline and amorphous dual sites. The dual phased nanoporous electrocatalyst exhibits high catalytic activity comparable to standard Pt-catalyst at higher current densities (> 60 mA cm(-2)). The electrocatalyst is stable even at high current densities (> 100 mA cm(-2)) and needs much lesser overpotential than that of standard Pt/C catalyst for HER reaction at high current densities. The dealloying of defect-free metallic glasses leads to the formation of a large number of catalytic active sites, and the introduction of Mo into the CuTi matrix leads to accelerated H-2 adsorption/desorption kinetics. The dealloyed metallic glass requires an overpotential of 220 mV vs. RHE to attain a current density of 100 mA cm(-2) in an alkaline HER reaction. Based on the advantages of nanoporous structure development from highly metastable metallic glasses, the high active surface area of nanoporous structure on a high conductive substrate, the exceptional stability for long term and at high current densities, the proposed nanoporous metallic glass composite electrode is of significance for a diversity of applications for green energy production. (C) 2021 Elsevier B.V. All rights reserved.