Titanium dioxide-coated copper electrodes for hydrogen production by water splitting

초록

Pt is the most commonly used electrode and catalyst materials for H-2 production via water splitting as it provides the highest Gibbs free energy of H-2 adsorption (Delta G(H)) an d overpotential. However, as Pt catalysts are expensive and difficult to mass-produce, several efforts have been made to identify suitable substitutes. Although Cu provides lower Delta G(H) and overpotential than Pt, it exhibits better catalytic performance than other catalysts and is suitable for H-2 production. However, corrosion of Cu may affect its stability of Cu electrode. To overcome this limitation, we have coated a layer of carbon on the copper electrode and then synthesized titanium dioxide-(TiO2-) on the C/Cu electrode for water splitting application. Carbon black (CB) has excellent electrical conductivity and stable resistance for effective working as an electrochemical catalyst, and TiO2 has diverse applications because of its low-cost, non-toxic, and corrosion-resistant charac- teristics. In this study, TiO2 was synthesized on C/Cu electrodes under UV irradiation for different durations. The optimum irradiation duration was determined to be 15 min via surface and electrochemical analyses. To identify the potential applications of this TiO2-C/Cu electrode, we used artificial wastewater as the electrolyte. The synthesized TiO2-C/Cu electrode exhibited better stability than C/Cu electrode. Further, H-2 production with TiO2-C/Cu electrode was higher than that with C/Cu electrode at the same current density. We also investigated the effect of TiO2-C/Cu electrode on decomposition of formaldehyde. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

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