Selective Photocatalytic Hydrogenation of α,β-Unsaturated Aldehydes on Au/CuCo₂O₄ Nanotubes under Visible-Light Irradiation

Photocatalysis for selective organic transformations has received tremendous attention recently. However, how to achieve high selectivity in the photocatalysis of organic reaction remains a challenge. In this work, we reported new hierarchical Au/CuCo₂O₄ nanotubes for highly selective and efficient photocatalytic hydrogenation of α,β-unsaturated aldehydes. The hierarchical Au/CuCo₂O₄ nanotubes consisting of CuCo₂O₄ nanosheets and Au nanoparticles were prepared by the spinning technique in combination with thermal treatment and photoreduction. The produced Au/CuCo₂O₄ nanotubes were tested as a visible-light-responsive catalyst for the selective hydrogenation of 5-hydroxymethylfurfural to 2,5-furandimethanol. At 20 °C, the catalyst exhibits a high turnover frequency (up to 2727.6 h^–1) with nearly 100% selectivity and 93% conversion. Moreover, the Au/CuCo₂O₄ photocatalyst is highly stable under the reaction conditions and has a wide scope of substrates. The excellent performance of Au/CuCo₂O₄ can be ascribed to the synergistic effect of Au nanoparticles and semiconducting CuCo₂O₄ nanosheets, which achieve an efficient interband electron transition in the metal/semiconductor heterostructures. The unique Au/CuCo₂O₄ heterostructures presented in this work provide not only a green method for the hydrogenation reactions but also an effective way to boost light-induced organic synthesis.