Multistage structural self-supported electrode via structural engineering on carbon nanofibers for efficient hydrogen evolution reaction at high current density

Pt -based catalysts suffered from the wastage of active sites, resulting in unsatisfactory actual catalytic performance and poor durability as non -self-supporting catalysts for alkaline hydrogen evolution reaction (HER). In this work, we designed a self-supporting electrode material with multi -level structure that utilized carbon nanofibers anchored with cobalt to load and stabilize Pt nanoparticles (Pt@Co/CNFs) for achieving high activity and stability in alkaline HER. The carbon nanofibers served as a framework, with cobalt nanoparticles as an electron donor that can transfer electrons to the metal Pt to accelerating water splitting. In addition, the morphology of the multi -level structure surface was controlled by the content of the reducing agent to giving the material excellent superhydrophilic/underwater superaerophobic properties with ultra -low Pt load (0.29 mg cm -2 ), which was beneficial for HER. HER test results showed that Pt@Co/CNFs exhibited great catalytic activity, with 1 10 = 15 mV and 1 100 = 101 mV. Besides, the stable mechanical structure and the stability of the designed catalytic surface and electron donor in the multi -level structure gave the material exceptional stability. During the 100 -hour stability test at 100 mA cm -2 , the voltage change was only 50 mV. Besides, utilizing the Pt@Co/CNFs self-supporting electrode directly in the AEM water electrolysis system, a cell voltage as low as 2.18 V was achieved at 500 mA cm -2 . Impressively, it demonstrated operational stability for over 200 h without noticeable decay. This work provides a promising approach for the development of advanced self-supporting electrode catalysts.