Surface oxygen vacancy induced solar light activity enhancement of a CdWO4/Bi2O2CO3 core-shell heterostructure photocatalystElectronic supplementary information (ESI) available. See DOI: 10.1039/c7cp02136d

• Main Authors: Yang, Chunming, Gao, Guimei, Zhang, Junjun, Liu, Ruiping, Fan, Ruicheng, Zhao, Ming, Wang, Yongwang, Gan, Shucai
• Format: Journal Article
• Language: English
• Published: 07.06.2017
• ISSN: 1463-9076; 1463-9084
• DOI: 10.1039/c7cp02136d

A CdWO 4 /Bi 2 O 2 CO 3 core-shell heterostructure photocatalyst was fabricated via a facile two-step hydrothermal process. Flower-like Bi 2 O 2 CO 3 was synthesized and functioned as the cores on which CdWO 4 nanorods were coated as the shells. Photoluminescence (PL) spectra and electron paramagnetic resonance (EPR) demonstrate that the CdWO 4 /Bi 2 O 2 CO 3 core-shell heterostructure photocatalyst possesses a large amount of oxygen vacancies, which induce defect levels in the band gap and help to broaden light absorption. The photocatalyst exhibits enhanced photocatalytic activity for Rhodamine B (RhB), methylene blue (MB), methyl orange (MO), and colorless contaminant phenol degradation under solar light irradiation. The heterostructured CdWO 4 /Bi 2 O 2 CO 3 core-shell photocatalyst shows drastically enhanced photocatalytic properties compared to the pure CdWO 4 and Bi 2 O 2 CO 3 . This remarkable enhancement is attributed to the following three factors: (1) the presence of oxygen vacancies induces defect levels in the band gap and increases the visible light absorption; (2) intimate interfacial interactions derived from the core-shell heterostructure; and (3) the formation of the n-n junction between the CdWO 4 and Bi 2 O 2 CO 3 . The mechanism is further explored by analyzing its heterostructure and determining the role of active radicals. The construction of high-performance photocatalysts with oxygen vacancies and core-shell heterostructures has great potential for degradation of refractory contaminants in water with solar light irradiation. A CdWO 4 /Bi 2 O 2 CO 3 core-shell heterostructure photocatalyst was fabricated via a facile two-step hydrothermal process.