Construction of CuO quantum Dots/WO3 nanosheets 0D/2D Z-scheme heterojunction with enhanced photocatalytic CO2 reduction activity under visible-light

• Published in: Journal of alloys and compounds 2021-03, Vol.858, p.157668, Article 157668
• Main Authors: Xie, Zhongkai, Xu, Yuyan, Li, Di, Chen, Lijie, Meng, Suci, Jiang, Deli, Chen, Min
• Format: Article
• Language: English
• Subjects: Carbon dioxide; Catalytic activity; Charge efficiency; Charge transfer; CO2 photoreduction; Current carriers; Heterointerfaces; Heterojunctions; Heterostructures; Light irradiation; Nanosheets; Narrow-bandgap; Oxidation; Photocatalysis; Quantum dots; Reduction; Self-assembly; Separation; Tungsten oxides; Z-scheme
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2020.157668

Construction of Z-scheme heterojunction has received more attention in photocatalytic CO2 reduction owing to its excellent charge carriers separation efficiency and unweakened redox capability of different active components. Herein, a novel CuO quantum dots (QDs)/WO3 nanosheets (NSs) 0D/2D Z-scheme heterojunction was synthesized by a self-assembly method. The CuO QDs with an average diameter of 1.6 nm are uniformly distributed on the WO3 NSs, affording a close interface and short charge diffusion distance, which can effectively promote the separation efficiency of charge carriers. Moreover, the Z-scheme charge transfer mechanism simultaneously keeps the strong reduction capability of CuO and oxidation of WO3, thus enhancing the photocatalytic CO2 reduction performance. Resulting from the 0D/2D structural benefits and Z-scheme charge transfer mechanism, the CuO QDs/WO3 NSs performs a much higher photocatalytic activity by reducing CO2 with H2O vapor into CO under visible-light irradiation, which is significantly higher than those of pure CuO and WO3. This study constructs a novel Z-scheme heterostructure by combining different narrow-bandgap semiconductors, which can possess a rapid charge transfer rate and superior redox ability in CO2 photoreduction. [Display omitted] •CuO QDs/WO3 NSs Z-scheme heterostructure was synthesized by uniformly loading the 0D non-noble metallic oxide CuO quantum dots onto the surface of 2D WO3 nanosheets by a self-assembly strategy.•CuO QDs/WO3 NSs composites exhibited a much higher photocatalytic activity compared with pure CuO and WO3.•The unique channel for Z-scheme charge transfer of CuO/WO3 create an enhanced redox ability for the photocatalytic CO2 reduction to CO with H2O.•The compactly connected heterointerface accelerate the charge transfer and decrease the photoinduced carrier recombination.