Facile fabrication of Ir/CNT/rGO nanocomposites with enhanced electrocatalytic performance for the hydrogen evolution reaction

Developing high-performance Ir-based catalysts for the hydrogen evolution reaction (HER) is important because of the unique catalytic activity of Ir in this process. An Ir colloidal precursor with the same size distribution of Ir nanoparticles was employed to prepare Ir-based electrocatalysts for the first time and explore the effects of different electrocatalytic supports, including active carbon, rGO, carbon nanotubes (CNTs), and CNT/rGO composites. The results indicate that the metal–support interactions in electronic transfer were not the key factor determining the electrocatalytic performance. Instead, the stability of the interaction between the supports and Ir nanoparticles was the key factor. It is exciting that the as-prepared Ir/CNT/rGO nanocomposite has enhanced properties; the overpotential of Ir/CNT/rGO is 19 mV at η10, and the overpotential is well maintained after 10 000 cycles. This work provides a promising electrocatalyst for HER and reveals the influential factors in electrocatalytic HER.