Biomimetic Polyimide-Supported Cuprous Oxide Photocatalytic Film with Tunable Hydrophobicity, Improved Thermal Stability, and Photocatalytic Activity toward CO₂ Reduction

Abstract

Flexible and thermally stable polyimide (PI) films containing a hierarchical surface structure were synthesized as substrates to support visible-light active cuprous oxide for photocatalytic reduction of carbon dioxide for the first time. With the nanocasting technique, the surface structure on the leaves of Xanthosoma sagittifolium was successfully duplicated on PI films. Followed by the ion-exchange process and adequate thermal treatment, cuprous oxide nanoparticles were successfully immobilized on the artificial PI leaves and exhibited the capability to photoreduce carbon dioxide into carbon monoxide under visible-light illumination. With the selection of biomimetic structures and adjustment of fabrication parameters, the hydrophobicity and optical absorption edge of the photocatalytic film were tunable. An increase in hydrophobicity improved the yield of carbon monoxide. The introduction of a hierarchical structure on the surface and cuprous oxide within the matrix dramatically enhanced the thermal stability of the PI film. The flexible photocatalytic film is a promising material for the applications requiring high mechanical and thermal stability, such as industrial flue-gas treatments.

Tailoring Copper Chemical Status and Hydrophobicity of Biomimetic Photocatalytic Films for Carbon Dioxide Conversion

“…On the other hand, the micrometerscale papillae connected with cuticular foldings were presented on t X PI, indicating the successful duplication of the leaf structure of Xanthosoma sagittifolium. 15 The smooth crosssectional image of the fracture surface of t S PI or t X PI (Figure 1(a′, b′)) suggested the dense and pore-free feature of biomimetic PI films. As shown in Figure 2, those hierarchical structures remained on PI after the cautiously controlled Cugrafting process.…”

DFT-Assisted Design of D–A Conjugated Polymers for Photocatalytic Reduction of Carbon Dioxide

“…Various research efforts based on hydrophobicity control have been reported in selectivity control of the photocatalytic CO 2 RR. ,, As reported, a hydrophilic photocatalyst would suffer from the HER more greatly than hydrophobic photocatalysts. To explore the catalyst nature for the CO 2 RR with high selectivity toward CO, physical and chemical modifications on AQT were applied to obtain photocatalysts with different hydrophobicities, which was measured by contact angle tests.…”

Fluid Field Modulation in Mass Transfer for Efficient Photocatalysis

“…durability, which would further enhance the photocatalytic activity of artificial cilia photocatalysts. [204] To further take advantages of cilia-like structure, Lu's group constructed ZnO nanorods on the surface of cilia and deposited CdS quantum dots on ZnO branches, forming heterostructure magnetically actuated artificial cilia film (ZCB-S), which exhibited 2.7 times higher photocatalytic hydrogen evolution activity (up to about 5500 μmol h -1 m -1 under magnet-actuation with 14 Hz) that without magnetic actuation situation (Figure 12 g). [205] The obvious improvement in photocatalytic performance was ascribed to the natural manipulation ability of cilia in fluid actuators, which promoted mass transfer and the desorption of hydrogen from active sites, facilitating continuous photocatalytic hydrogen generation reaction (Figure 12 h).…”

“…corroborated that compared with photocatalyst film, cilia‐like structure endowed photocatalyst with higher surface area, better light harvesting ability and greater practical durability, which would further enhance the photocatalytic activity of artificial cilia photocatalysts. [ 204 ]…”