Delaminated CoAl‐Layered Double Hydroxide@TiO₂ Heterojunction Nanocomposites for Photocatalytic Reduction of CO₂

<jats:title>Abstract</jats:title><jats:p>Photocatalytic reduction offers an attractive route for CO<jats:sub>2</jats:sub> utilization as a chemical feedstock for solar fuels production but remains challenging due to the poor efficiency, instability, and/or toxicity of current catalyst systems. Delaminated CoAl‐layered double hydroxide nanosheets (LDH‐DS) combined with TiO<jats:sub>2</jats:sub> nanotubes (NTs) or nanoparticles (NPs) are promising nanocomposite photocatalysts for CO<jats:sub>2</jats:sub> reduction. Heterojunction formation between visible light absorbing delaminated CoAl nanosheets and UV light absorbing TiO<jats:sub>2</jats:sub> nanotubes greatly enhances interfacial contact between both high aspect ratio components relative to their bulk counterparts. The resulting synergic interaction confers a significant improvement in photoinduced charge carrier separation, and concomitant aqueous phase CO<jats:sub>2</jats:sub> photocatalytic reduction, in the absence of a sacrificial hole acceptor. CO productivity for a 3 wt% LDH‐DS@TiO<jats:sub>2</jats:sub>‐NT nanocomposite of 4.57 µmol g<jats:sub>cat</jats:sub><jats:sup>‐1</jats:sup> h<jats:sup>‐1</jats:sup> exhibits a tenfold and fivefold increase over that obtained for individual TiO<jats:sub>2</jats:sub> NT and delaminated CoAl‐LDH components respectively and is double that obtained for 3 wt% bulk‐LDH@TiO<jats:sub>2</jats:sub>‐NT and 3 wt% LDH‐DS@TiO<jats:sub>2</jats:sub>‐NP catalysts. Synthesis of delaminated LDH and metal oxide nanocomposites represents a cost‐effective strategy for aqueous phase CO<jats:sub>2</jats:sub> reduction.</jats:p>