Hydrogen evolution reaction at the interface of Ni–Cu bi-metallic catalyst supported at TiO2–C matrix-nanostructures prepared from phytochemical sources

A promising approach for hydrogen evolution reaction (HER) as an energy source on non-noble metal nanostructures supported on phytochemically-derived TiO₂ is discussed in this work. The investigation is focused on the synergistic effect of Ni–Cu catalyst on carbon vulcan-TiO₂ (C–TiO₂) material in alkaline conditions. Among Ni:Cu ratios, nanoparticles of Ni₆₀Cu₄₀ resulted as the best electrocatalyst for HER, which was loaded over composites of carbon vulcan with TiO₂ prepared from phytochemical sources such as cinnamon (C-TC), spinach (C-TE), and commercial TiO₂ (C-T0). It has been demonstrated that Ni₆₀Cu₄₀/C-TC attains a higher activity towards HER owing to semiconductor nanostructures (from cinnamon) properties. The results are supported by electrochemical characterization (linear voltammetry, ECSA, EIS), including in-situ differential electrochemical mass spectrometry (DEMS) to monitoring hydrogen production in the working electrode side and oxygen evolution reaction (OER) in the counter electrode (CE) side. The morphological and structural characterization of the samples was carried out using XRD, TEM, Raman, UV-VIS, N₂ physisorption (BET), SEM and XPS.