• Oh, Sangho
• Kang, Hoyoung
• Joo, Wonhyo
• Joo, Young-Chang

Abstract

<jats:title>Abstract</jats:title><jats:p>Although cuprous oxide, Cu<jats:sub>2</jats:sub>O, has attracted attention as a promising p‐type semiconductor material for carbon dioxide reduction (CO<jats:sub>2</jats:sub>RR) photocatalysts, serious stability problems have always occurred due to photocorrosion. In this work, we fabricated hierarchical‐structured photocathodes with CuFeO<jats:sub>2</jats:sub> on Cu<jats:sub>2</jats:sub>O nanorods by spray pyrolysis and oxygen‐controlled heat treatment to improve the stability of Cu<jats:sub>2</jats:sub>O from a thermodynamic perspective. Field‐emission scanning electron microscopy, field‐emission transmission electron microscopy and X‐ray diffraction confirmed that the Cu<jats:sub>2</jats:sub>O/CuFeO<jats:sub>2</jats:sub> hierarchical nanorod structure was successfully fabricated. It was observed that the photocathodes show enhanced stability as the Fe content increases. Therefore, we report that the CuFeO<jats:sub>2</jats:sub> layer enhances the stability of the Cu<jats:sub>2</jats:sub>O nanorod photocathode. A photocathode with a Cu : Fe atomic ratio of 1.52 : 1 has a current density of 1.1 mA/cm<jats:sup>2</jats:sup> at 0.35 V<jats:sub>RHE</jats:sub> even after 10 linear voltage sweep repetitions, a decrease of only 8 % compared to the current density at the first sweep. Additionally, formate and acetate were produced during the CO<jats:sub>2</jats:sub>RR, exhibiting faradaic efficiencies (FEs) of 21.6 % and 68.6 %, respectively.</jats:p>

Topics

• density
• Carbon
• scanning electron microscopy
• Oxygen
• semiconductor
• transmission electron microscopy
• current density
• spray pyrolysis