Achieving highly efficient pH-universal hydrogen evolution by superhydrophilic amorphous/crystalline Rh(OH)3/NiTe coaxial nanorod array electrode

Abstract

Design of high-performance pH-universal electrocatalysts is critical to practical large-scale hydrogen generation as a carbon-neutral fuel, yet challenging. Herein, we report an unique motif with crystalline nickel tellurium nanorods enclosed by amorphous rhodium hydroxide (a-Rh(OH)3/NiTe), formed through a hydrothermal synthesis and a subsequent chemical etching process, to address this challenge. The as-prepared a-Rh(OH)3/NiTe cathode enables a current density of 100 mA cm−2 with low overpotentials of 51, 109, and 64 mV for HER in alkaline, neutral and acidic media, respectively. As revealed by density functional theory (DFT) calculations, the electronic interactions between a-Rh(OH)3 and NiTe enhance the performance of Rh active sites. More importantly, the motif possesses superhydrophilicity and aerophobicity features, which not only facilitates the access to electrolytes but also ensures the fast release of hydrogen bubbles, endowing the electrocatalyst with advanced pH-universal HER activity. This work provides insights for the design of highly efficient electrocatalysts for hydrogen evolution at both molecular and mesoscopic levels.