High-entropy alloy nanocages with highly ordered {100} facets and ultrathin features for water splitting in an acidic medium

• Published in: Journal of materials chemistry. A, Materials for energy and sustainability Vol. 12; no. 26; pp. 1643 - 1651
• Main Authors: Su, Keying, Yang, Shan, Zhu, Yulu, Liang, Yujia, Tang, Yawen, Qiu, Xiaoyu
• Format: Journal Article
• Language: English
• Published: Cambridge Royal Society of Chemistry 02.07.2024
• Subjects: Catalysts; Catalytic activity; Entropy; Etching; High entropy alloys; Nanoparticles; Oxygen evolution reactions; Synergistic effect; Water splitting
• ISSN: 2050-7488; 2050-7496
• DOI: 10.1039/d4ta02556c

High-entropy alloy (HEA) nanoparticles have been recognized as one kind of efficient electro-catalyst for water splitting. However, their higher catalytic activity is restrained by the difficulty in precisely shaping the HEAs into ordered facets and fully exposed surface structures. Herein, we report a seed-mediated conformal growth and partial etching method for the controlled synthesis of PtIrRuRhPd HEA cubic nanocages (CNCs), which feature the ordered {100} facets and ultrathin shells of five atomic layers. The slow injection of a PtIrRuRh layer on Pd nanocubes and the subsequent capture of dissociative Pd atoms in the etching step are responsible for the formation of nearly equimolar PtIrRuRhPd HEAs. Due to the synergistic effects derived from the multicomponent high-entropy effects, the ordered (100) facets, and the ultrathin feature, the PtIrRuRhPd HEA CNCs exhibit significantly high electro-catalytic activities for hydrogen and oxygen evolution reactions in an acidic medium, with overpotentials of 20 mV and 272 mV at 10 mA cm −2 ( η 10 ), respectively. As electrodes for a water electrolyzer, the PtIrRuRhPd HEA CNCs afford an η 10 as low as 196 mV, together with superior long-term durability for 200 000 s. PtIrRuRhPd HEA cubic nanocages with ordered {100} facets and ultrathin shells exhibit high electro-catalytic activities for hydrogen and oxygen evolution reactions in an acidic medium.