Facile Synthesis of Novel CaIn2S4/ZnIn2S4 Composites with Efficient Performance for Photocatalytic Reduction of Cr(VI) under Simulated Sunlight Irradiation
A series of novel and efficient heterostructured composites CaIn2S4/ZnIn2S4 have been synthesized using a facile hydrothermal method. XRD patterns indicate the as-prepared catalysts are two-phase composites of cubic phase CaIn2S4 and hexagonal phase ZnIn2S4. FESEM (field emission scanning electron m...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2018-06-01
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| Series: | Nanomaterials |
| Subjects: | |
| Online Access: | http://www.mdpi.com/2079-4991/8/7/472 |
| Summary: | A series of novel and efficient heterostructured composites CaIn2S4/ZnIn2S4 have been synthesized using a facile hydrothermal method. XRD patterns indicate the as-prepared catalysts are two-phase composites of cubic phase CaIn2S4 and hexagonal phase ZnIn2S4. FESEM (field emission scanning electron microscope) images display that the synthesized composites are composed of flower-like microspheres with wide diameter distribution. UV–Vis diffuse reflectance spectra (DRS) show that the optical absorption edges of the CaIn2S4/ZnIn2S4 composites shift toward longer wavelengths with the increase of the CaIn2S4 component. The photocatalytic activities of the as-synthesized composites are investigated by using the aqueous-phase Cr(VI) reduction under simulated sunlight irradiation. This is the first report on the application of the CaIn2S4/ZnIn2S4 composites as stable and efficient photocatalysts for the Cr(VI) reduction. The fabricated CaIn2S4/ZnIn2S4 composites possess higher photocatalytic performance in comparison with pristine CaIn2S4 or ZnIn2S4. The CaIn2S4/ZnIn2S4 composite with a CaIn2S4 molar content of 30% exhibits the optimum photocatalytic activity. The primary reason for the significantly enhanced photoreduction activity is proved to be the substantially improved separation efficiency of photogenerated electrons/holes caused by forming the CaIn2S4/ZnIn2S4 heterostructured composites. The efficient charge separation can be evidenced by steady-state photoluminescence spectra (PLs) and transient photocurrent response. Based on the charge transfer between CaIn2S4 and ZnIn2S4, an enhancement mechanism of photocatalytic activity and stability for the Cr(VI) reduction is proposed. |
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| ISSN: | 2079-4991 |