Equilibrated PtIr/IrOx Atomic Heterojunctions on Ultrafine 1D Nanowires Enable Superior Dual‐Electrocatalysis for Overall Water Splitting. Issue 20 (14th April 2022)

• Record Type: Journal Article
• Authors: Huang, Hongpu; Fu, Luhong; Kong, Weiqiang; Ma, Hairui; Zhang, Xue; Cai, Junlin; Wang, Shupeng; Xie, Zhaoxiong; Xie, Shuifen
• Is Part Of: Small. Volume 18:Issue 20(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-04-14
• Subjects: atomic heterojunctions -- electronic modulation -- overall water splitting -- Pt–IrOx dual‐sites -- ultrafine hybrid nanowires; Nanotechnology -- Periodicals; Nanoparticles -- Periodicals; Microtechnology -- Periodicals; 620.5
• DOI: 10.1002/smll.202201333
• Languages: English
• ISSNs: 1613-6810

Abstract

Abstract: Dual‐active‐sites atomically coupled on ultrafine 1D nanowires (NWs) can offer synergic atomic heterojunctions (AHJs) and high atomic‐utilization toward multipurpose and superior catalysis. Here, ≈2‐nm‐thick PtIr/IrO x hybrid NWs are elaborately synthesized with equilibrated Pt/IrO x AHJs as high‐efficiency bifunctional electrocatalysts for overall water splitting. Mechanism studies reveal the atomically coupled Pt–IrO x dual‐sites are favorable for facilitating water dissociation, alleviating the binding of H* on Pt sites and inversely regulating the *OH adsorption and oxidation on bridge Ir–Ir sites. By simply equilibrating the Pt–IrO x ratio, the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) can be substantially accelerated. In particular, Pt‐rich PtIr/IrO x ‐30 NWs attain 11‐fold enhancements for HER compared to Pt/C in 1.0 m KOH, while IrO x ‐rich PtIr/IrO x ‐50 NWs express about five times mass activity referring to Ir/C for OER. Remarkably, the ratio‐optimized PtIr/IrO x NWs electrode couple achieves a durably continuous H2 production under a substantially low cell voltage. Abstract : Ultrafine PtIr/IrO x hybrid nanowires with equilibrated Pt/IrO x atomic heterojunctions are elaborately synthesized to serve as high‐performance dual‐function electrocatalysts for overall water splitting in alkaline conditions. Atomically coupled Pt–IrO x dual‐sites can mutually arouse electronic‐modulation for substantially accelerating the hydrogen evolution reaction and oxygen evolution reaction, respectively.