One-dimensional iridium-based nanowires for efficient water electrooxidation and beyond

The sluggish reaction kinetics of oxygen evolution reaction(OER)has largely lowered the efficiency of electrochemical water splitting.Ir represents one of the state-of-the-art electrocatalysts for promoting OER especially in acidic electrolytes.However,it remains a formidable challenge to synthesize high-quality one-dimensional(1D)Ir-based nanostructures for improved electrocatalytic performance.Herein,a template-assisted synthesis method is reported wherein 1D porous Ir-Te nanowires(Ir-Te NWs)are synthesized with Te NWs serving as the template.The Ir-Te NWs exhibit highly enhanced OER performance compared to commercial IrO_(2) and Ir/C.In detail,the overpotentials to reach 10 mA cm^(-2) are 248 and 284 mV in 1 M KOH and 0.5 M H2S04,respectively,much lower than those of commercial catalysts.The Ir-Te NWs also show smaller Tafel slopes than commercial IrO_(2) and Ir/C,signifying faster reaction kinetics.Besides,much more durable OER activity can be maintained for Ir-Te NWs with negligible decay during 25 and 20 h stability tests in 1 M KOH and 0.5 M H_(2)SO_(4),respectively.Further analysis indicates that the significantly improved OER performance of Ir-Te NWs could be ascribed to the larger electrochemical surface area and smaller electrical resistance.More significantly,the templated synthesis of Ir-Te NWs can be facilely extended to the fabrication of other metal-Te NWs including Ru-Te,Rh-Te and Pt-Te NWs.The design and synthesis of 1D metal-based NWs in this work provide important inspiration for the synthesis of diversified 1D metallic nanostructures with distinctly enhanced catalytic performance and beyond.