Equilibrated PtIr/IrOx Atomic Heterojunctions on Ultrafine 1D Nanowires Enable Superior Dual-Electrocatalysis for Overall Water Splitting.
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; 18(20): e2201333, 2022 05.
Article
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| MEDLINE
| ID: mdl-35419953
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/IrOx hybrid NWs are elaborately synthesized with equilibrated Pt/IrOx AHJs as high-efficiency bifunctional electrocatalysts for overall water splitting. Mechanism studies reveal the atomically coupled Pt-IrOx 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-IrOx ratio, the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) can be substantially accelerated. In particular, Pt-rich PtIr/IrOx -30 NWs attain 11-fold enhancements for HER compared to Pt/C in 1.0 m KOH, while IrOx -rich PtIr/IrOx -50 NWs express about five times mass activity referring to Ir/C for OER. Remarkably, the ratio-optimized PtIr/IrOx NWs electrode couple achieves a durably continuous H2 production under a substantially low cell voltage.
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MEDLINE
Assunto principal:
Nanofios
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En
Ano de publicação:
2022
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Article