Beschreibung:
<jats:title>Abstract</jats:title><jats:p>To achieve substantial reductions in CO<jats:sub>2</jats:sub> emissions, catalysts for the photoreduction of CO<jats:sub>2</jats:sub> into value‐added chemicals and fuels will most likely be at the heart of key renewable‐energy technologies. Despite tremendous efforts, developing highly active and selective CO<jats:sub>2</jats:sub> reduction photocatalysts remains a great challenge. Herein, a metal oxide heterostructure engineering strategy that enables the gas‐phase, photocatalytic, heterogeneous hydrogenation of CO<jats:sub>2</jats:sub> to CO with high performance metrics (i.e., the conversion rate of CO<jats:sub>2</jats:sub> to CO reached as high as 1400 µmol g cat<jats:sup>−1</jats:sup> h<jats:sup>−1</jats:sup>) is reported. The catalyst is comprised of indium oxide nanocrystals, In<jats:sub>2</jats:sub>O<jats:sub>3−</jats:sub><jats:italic><jats:sub>x</jats:sub></jats:italic>(OH)<jats:italic><jats:sub>y</jats:sub></jats:italic>, nucleated and grown on the surface of niobium pentoxide (Nb<jats:sub>2</jats:sub>O<jats:sub>5</jats:sub>) nanorods. The heterostructure between In<jats:sub>2</jats:sub>O<jats:sub>3−</jats:sub><jats:italic><jats:sub>x</jats:sub></jats:italic>(OH)<jats:italic><jats:sub>y</jats:sub></jats:italic> nanocrystals and the Nb<jats:sub>2</jats:sub>O<jats:sub>5</jats:sub> nanorod support increases the concentration of oxygen vacancies and prolongs excited state (electron and hole) lifetimes. Together, these effects result in a dramatically improved photocatalytic performance compared to the isolated In<jats:sub>2</jats:sub>O<jats:sub>3−</jats:sub><jats:italic><jats:sub>x</jats:sub></jats:italic>(OH)<jats:italic><jats:sub>y</jats:sub></jats:italic> material. The defect optimized heterostructure exhibits a 44‐fold higher conversion rate than pristine In<jats:sub>2</jats:sub>O<jats:sub>3−</jats:sub><jats:italic><jats:sub>x</jats:sub></jats:italic>(OH)<jats:italic><jats:sub>y</jats:sub></jats:italic>. It also exhibits selective conversion of CO<jats:sub>2</jats:sub> to CO as well as long‐term operational stability.</jats:p>