RuCo Nanoparticles Embedded on Carbon Nanotubes through Spray Drying for Enhanced Hydrogen Evolution Electrocatalysis

Design and fabrication of a non-Pt hydrogen evolution catalyst for acidic and alkaline solutions are of paramount significance for water splitting. Herein, we proposed a method through spray-drying coupling high-temperature reduction, which had simple, efficient, and wide-scale applications compared with the traditional synthetic process, and a RuCo NPs/CNTs hydrogen evolution catalyst was fabricated successfully. Zero-dimensional (0D) RuCo nanoparticles (<10 nm) embedded on one-dimensional (1D) CNTs uniformly and CNTs involving each other could offer numerous mass transfer pore canals and a large active specific surface area; on the other hand, Ru would possess an enhanced HER activity with the incorporation of Co for optimizing the adsorption energy of intermediates by the synergistic effect, which was verified through DFT calculation. Benefitting from the porous structure and metallic nanostructure, the RuCo NPs/CNTs-400 °C prepared in this paper showed excellent hydrogen evolution reaction (HER) performance, with low overpotentials of 39 and 27 mV at the current density of 10 mA·cm–2, small Tafel slopes of 32 and 27 mV·dec–1, and superior durability for 24 h in 0.5 M H2SO4 and 1.0 M KOH solutions, respectively. The proposed method in this paper may provide valuable strategies for developing varied catalysts for other catalysis fields.