7787-63-5Relevant articles and documents
Low-temperature reaction of Aurivillius phases with halides
Sitharaman,Sleight
, p. 416 - 416 (2000)
Kijima et al. [T. Kijima, S. Kimura, Y. Kawahara, K. Ohe, M. Yada, and M. Machida, J. Solid State Chem. 146, 60 (1999)] recently reported a reaction between Bi4Ti3O12 and LiI in the presence of iodine at 350°C. Their product was never obtained free of Bi4Ti3O12, but their claim was that their product was Bi4Ti3O12 intercalated with I and Li. We have repeated this reaction and found conditions under which the reaction goes to completion, i.e., Bi4Ti3O12 is completely consumed. The dominant crystalline product is apparently identical to the product reported by Kijima et al. However, we conclude that no intercalation of Bi4Ti3O12 has occurred. This dominant crystalline phase is in fact BiOI. The remainder of the product is poorly crystalline. Analogous reactions occur at low temperature using other halides such as NaCl and other Aurivillius phases such as Bi2WO6. (C) 2000 Academic Press.
Tailoring AgI nanoparticles for the assembly of AgI/BiOI hierarchical hybrids with size-dependent photocatalytic activities
Cheng, Hefeng,Wang, Wenjun,Huang, Baibiao,Wang, Zeyan,Zhan, Jie,Qin, Xiaoyan,Zhang, Xiaoyang,Dai, Ying
, p. 7131 - 7136 (2013)
A facile ion exchange route between BiOI hierarchical microspheres and AgNO3 solution is explored to synthesize AgI/BiOI hierarchical hybrids that consist of AgI nanoparticles (NPs) uniformly anchored on the surface of BiOI nanosheets. With the addition of poly(vinylpyrrolidone) (PVP) surfactant molecules, the size of the AgI NPs can be tailored in the range of 55-16 nm. Evaluated by the photodecomposition of 2,4-dichlorophenol (2,4-DCP) solution under visible light irradiation, the AgI NPs/BiOI hybrids displayed highly efficient photocatalytic activities. What is more, as the size of the AgI NPs decreases, the AgI/BiOI hybrids exhibit enhanced photocatalytic performance, which is believed to be related to the larger number of surface active sites and faster spatial charge transfer. The Royal Society of Chemistry 2013.
ZnWO4/BiOI heterostructures with highly efficient visible light photocatalytic activity: The case of interface lattice and energy level match
Li, Pan,Zhao, Xian,Jia, Chun-Jiang,Sun, Honggang,Sun, Liming,Cheng, Xiufeng,Liu, Li,Fan, Weiliu
, p. 3421 - 3429 (2013)
ZnWO4/BiOI heterostructures with different constituents are synthesized via a chemical bath approach under mild conditions by tuning the Zn/Bi molar ratios. The obtained ZnWO4/BiOI heterostructures display high photocatalytic activities in degradation of MO and photocurrent response under visible light irradiation. Combining the experimental findings, first-principles calculations are used to investigate the surface geometry structures and the work functions of the (011) and (010) surfaces of the ZnWO4 phase and the (001) surface of the BiOI phase. The results show that the lattice and energy levels between the ZnWO4 and BiOI phases match well with each other to be capable of forming efficient ZnWO 4/BiOI p-n heterojunction structures. This match promotes the separation and transfer of photoinduced electron-hole pairs at the interface, resulting in the excellent photocatalytic performance of the ZnWO 4/BiOI heterostructures. Our findings show that the formation of a heterostructure would possess the excellent photocatalytic activities only if the lattice and energy level match between the two semiconductors was satisfied, which is of great importance for designing and developing more efficient heterostructured photocatalysts.
Dramatic visible light photocatalytic activity of MnOx-BiOI heterogeneous photocatalysts and the selectivity of the cocatalyst
Ye, Liqun,Liu, Xiaodi,Zhao, Qiang,Xie, Haiquan,Zan, Ling
, p. 8978 - 8983 (2013)
Charge separation is very important for increasing the activity of semiconductor-based photocatalysts. Here we show that the main active species of BiOI are photo-induced holes, rather than OH and O2-, under visible light irradiation. Based on this finding, the cocatalyst MnO x was used to enhance the transfer of the photo-induced holes, resulting in much higher photocatalytic activity, compared with the photocatalyst without MnOx. MnOx-BiOI heterogeneous nanostructure photocatalysts have been prepared by photo-deposition in Mn(NO3)2 solution, and characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM) and photoluminescence (PL) spectroscopy. As-prepared MnOx-BiOI exhibited higher photoactivity than BiOI and Pt-BiOI for the degradation of Rhodamine B (RhB) dye under visible light irradiation. The PL spectrum showed that MnO x enhances the separation efficiency of the photo-induced electrons and holes of BiOI. Finally, BiOI was selectively combined with a deriving-hole-type cocatalyst to enhance the photocatalytic activity, and the reason for the cocatalyst selectivity is also discussed. This finding may be useful in bismuth-based photocatalysts to construct highly efficient solar energy conversion systems.
Bismuth oxyiodide heterojunctions in photocatalytic degradation of phenolic molecules
Han, Aijuan,Chian, Siew Fung,Toy, Xiu Yi,Sun, Jiulong,Jaenicke, Stephan,Chuah, Gaik-Khuan
, p. 9509 - 9520 (2015)
Bismuth oxyiodide composites were synthesized and tested as photocatalysts under visible light irradiation. Calcination of bismuth oxyiodide, BiOI, at 420 °C for various lengths of time led to composites with varying compositions of Bi7O9I3 and α-Bi5O7I. The ease of forming iodide-poor bismuth oxyhalides can be attributed to ready loss of the strongly reducing iodide ion. Thermogravimetric measurements show that BiOI is not thermally stable above 350 °C. The Bi7O9I3/a- Bi5O7I composites formed active visible-light photocatalysts for the degradation of phenol, p-chlorophenol, p-cresol, and 4-tert-butylphenol. Compared to BiOI, the rate constant for the photodegradation of phenol was 5-6 times higher over the Bi7O9I3/α-Bi5O7I composites. The excellent activity can be attributed to the efficient separation of photogenerated charge carriers at the intimately contacted heterojunctions of the in situ-generated composites.
Core-shell Cd0.2Zn0.8S@BiOX (X = Cl, Br and I) microspheres: A family of hetero-structured catalysts with adjustable bandgaps, enhanced stability and photocatalytic performance under visible light irradiation
Zhou, Yannan,Wen, Ting,Chang, Binbin,Yang, Baocheng,Wang, Yonggang
, p. 13709 - 13716 (2016/09/09)
Heterostructures consisting of two semiconductors have merited considerable attention in photocatalytic applications due to synergistic effects in complex redox processes. The incorporation of solid solutions into such architectures can further offer extra variability to control the bandgap. In this study, we report the fabrication of a series of core-shell Cd0.2Zn0.8S@BiOX (X = Cl, Br and I) microspheres via a solvothermal route that lead to enhanced photocatalytic performance under visible light irradiation. By optimizing the synthesis conditions, uniform and porous Cd0.2Zn0.8S@BiOX microspheres were achieved. The products were thoroughly characterized by X-ray diffraction studies, scanning electron microscopy, transmission electron microscopy, photoluminescence studies, absorption measurements and the photodegradation of RhB. Remarkably, the electronic structures of Cd0.2Zn0.8S@BiOX composites can be continuously tuned by varying the composition of BiOX to achieve the best catalytic performance under visible light irradiation. Finally, this greatly enhanced visible-light-driven photocatalytic efficiency was observed in the optimized Cd0.2Zn0.8S@BiOI composites when compared to their single-component counterparts, which may be attributed to increased light absorption and improved electron-hole separation. The photocatalytic mechanism has also been proposed based on the experimental evidences and the theoretical band positions of Cd0.2Zn0.8S@BiOI.
