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Synthesis and characterization of Bi2WO6 nanoplates using egg white as a biotemplate through sol-gel method
Materials Letters 139 (2015) 401–404
Contents lists available at ScienceDirect
Materials Letters journal homepage: www.elsevier.com/locate/matlet
Synthesis and characterization of Bi2WO6 nanoplates using egg white as a biotemplate through sol-gel method Yumin Liu n, Hua Lv, Jiayuan Hu, Zijin Li Collaborative Innovation Center of Henan Province for Green Manufacturing of Fine Chemicals, School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang, Henan 453007, P. R. China
art ic l e i nf o
a b s t r a c t
Article history: Received 5 August 2014 Accepted 24 October 2014 Available online 4 November 2014
Bi2WO6 nanoplates with thickness of about 100 nm had been successfully synthesized by sol-gel method using egg white proteins (albumin) as a biotemplate. On the basis of results of morphologies observation, it was found that albumin was critical for controlling the morphologies of the final products. Photocatalytic activities of the samples were evaluated by the degradation of Rhodamine B (RhB) under visible light irradiation. Due to the combined effects of high specific area, high light absorption and efficient separation of photogenerated electron-hole pairs, Bi2WO6 photocatalyst synthesized in the presence of albumin exhibited better photocatalytic activity than that Bi2WO6 synthesized without using albumin. & 2014 Elsevier B.V. All rights reserved.
Keywords: Bi2WO6 Albumin Semiconductors Sol-gel preparation
1. Introduction Bismuth tungstate (Bi2WO6), as one of the simplest numbers of Aurivillius oxide family of layered perovskite, is composed of accumulated layers of alternating fluorite-like (WO4)2- sheets and perovskite-like (Bi2O2)2 þ layers[1]. Since Kudo and Hijii firstly demonstrated the photocatalytic splitting water for O2 evolution over Bi2WO6[2], extensive attention had been paid to Bi2WO6 for its potential applications in solar-energy-transfer and photocatalytic fields. However, the practical applications of Bi2WO6 have been strictly limited due to its relatively low photocatalytic activity. To improve the photocatalytic activity of Bi2WO6, various methods, such as solid-state reaction[3], sol-gel process[4], hydrothermal and solvothermal method[1,5], have been reported to synthesize Bi2WO6 with various morphologies and architectures. As for sol-gel method, the gelata plays an important role in the mineralization for controlling the structure, morphology and diameter size of the final products. Egg white proteins (albumin) contain more than 20 amino acids and are well known for the high nutrition quality[6]. Besides that, egg white has been widely used as a binder cum gel forming material because of its high solubility in water and having the ability to associate with metal ions in solution. For example, Hu et al. have prepared the stack-like crystallization of calcium carbonate using egg white as a gelata [6]. The platelike clusters of CeO2 nanoparticles with particle size of 6-30 nm have been successfully prepared in the presence of
n
Corresponding author. Tel.: þ 86 373 3326335; fax: þ 86 373 3326336. E-mail address: [email protected] (Y. Liu).
http://dx.doi.org/10.1016/j.matlet.2014.10.131 0167-577X/& 2014 Elsevier B.V. All rights reserved.
freshly extracted egg white[7]. Inspired by the above efforts, we herein present a simple, innovative and environment friendly approach for the synthesis of Bi2WO6 nanoplates using egg white proteins as a gelata through sol-gel method. In addition, the enhanced photocatalytic activity for Bi2WO6 nanoplates was also systematically investigated.
2. Experimental 2.1. Materials and synthesis In a typical procedure, the freshly extracted egg white (5 ml) was mixed with 25 ml deionized water under stirring until a homogeneous solution was obtained. Then, 0.6 mmol of Bi (NH3)2C6H7O7 H2O and 0.043 mmol of (NH4)6W7O24 6 H2O were slowly added to the egg white solution to obtain a well-dissolved solution. The as-formed transparent mixture solution was evaporated at 80 oC in the air until the formation of yellow sticky gelatin. The gelatin was dried in the oven at 80 oC for the whole night and then calcined in a muffle furnace at 500 oC for 2 h to obtain the Bi2WO6 nanoplates (denoted as EBWO). For comparison, Bi2WO6 sample was also synthesized by replacing the egg white solution with an equal volume of deionized water (denoted as BWO), while the other experimental conditions remained the same. 2.2. Characterization The crystal structure of the samples was determined by XRD (Bruker D8 Advance, Germany) using graphite monochromatic
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Y. Liu et al. / Materials Letters 139 (2015) 401–404
copper radiation (Cu Kα). Morphologies and structures of the samples were observed by SEM (JEOL JSM-63901, Japan) and TEM (JEOL JEM-2100, Japan). The Brunauer-Emmett-Teller (BET) specific surface area was determined on a Surface Area Analyzer (NOVA2000e, USA) at liquid nitrogen temperature. The optical absorption spectra of samples were recorded by UV–vis diffuse reflectance spectra (Cary5000 UV–vis-NIR) using BaSO4 as a reference. Photoluminescence (PL) spectra were measured by using a Fluorescence Spectrophotometer (FP-6500, Japan) equipped with a Xenon lamp at an excitation wavelength of 300 nm. 2.3. Photocatalytic test Typically, 0.1 g catalyst (EBWO or BWO) was added into 100 ml RhB aqueous solution (5 mg L-1). After ultrasonic dispersion for 10 min, the suspension was then stirred for 30 min in the dark to reach the adsorption-desorption equilibrium. Then, the solution was exposed to simulated visible light irradiation using a 300 W Xe lamp. At given time intervals, about 5 ml of the suspension was collected for further analysis after centrifugation. The concentration of RhB was determined using UV–vis spectrophotometer at λmax of 553 nm. 3. Results and discussion The structure and morphology of the as-prepared Bi2WO6 were characterized by XRD, SEM and TEM. As shown in Fig. 1A, all the diffraction peaks of Bi2WO6 samples synthesized with and without albumin match well with the pure orthorhombic phase of Bi2WO6 (card no. 39-0256), and no characteristic peaks for impurities can
be detected. Moreover, the BWO sample exhibits higher intensity and narrower diffraction peaks than that of EBWO sample, indicating that the existence of albumin can decrease the crystalline grain growth and consequently result in small crystal size. The average crystal sizes of BWO and EBWO samples are 37.3 nm and 32.6 nm, respectively, using FWHM of (1 1 3) diffraction peak at 28.8o with the famous Scherrer equation. A panoramic SEM image (Fig. 1B) indicates that BWO sample is almost entirely composed of large quantities of irregular block particles and agglomerated plates. While, EBWO sample (Fig. 1C and Fig. 1D) exhibits well dispersed nanoplates-like morphology with thickness of ~100 nm and the other two dimensions of several micrometers. The interplanar spacing of EBWO sample (inset of Fig. 1D) is determined to be 0.273 nm, corresponding to d spacing of (0 2 0) plane of orthorhombic Bi2WO6. Compared to BWO sample, we believe that albumin used as gelling agent and stabilizer is critical for the formation of nanoplates Bi2WO6, which may adsorb onto surfaces of the nucleating Bi2WO6 to regulate the lamellar growth and inhibit the agglomerate tendency of the growing plates during the preparing process. The optical properties of as-prepared Bi2WO6 samples were measured by UV–vis diffuse reflectance spectroscopy. As shown in Fig. 2A, both samples have a broad absorption from the UV light to visible light region due to the band gap transition. It is noteworthy that EBWO sample exhibits an enhanced optical absorption in the visible light region compared to BWO sample. After the calculation [8], the band gaps (Eg) of EBWO and BWO samples are estimated to be about 2.83 eV and 3.04 eV from the onsets of the absorption edges (inset of Fig. 2A), respectively. Taking the efficient utilization of visible light into account, we believe that EBWO sample, with long wavelength absorption band and enhanced absorption in the
Fig. 1. (A) XRD pattern. (B) SEM image of BWO. (C) SEM image of EBWO (Inset is the magnified image). (D) TEM image of EBWO (Inset is the corresponding HRTEM image).
Y. Liu et al. / Materials Letters 139 (2015) 401–404
403
Fig. 2. (A) UV–vis diffuse reflectance spectra and the corresponding (αhv)2 vs (hv) curves (inset) of samples. (B) N2 adsorption-desorption isotherms and (C) pore-size distribution curves of samples. (D) PL spectrum of samples.
visible light region, is an efficient photocatalyst for decomposition of organic contaminants under visible light irradiation. Fig. 2B shows the nitrogen adsorption/desorption isotherms of EBWO and BWO samples. These isotherms can be classified to type IV with H3-type hysteresis loops at high relative pressures, indicating the characteristic of mesoporous feature. These porous structures can be ascribed to the irregular stacking of Bi2WO6 plates which give rise to slit-shaped pores. Moreover, the hysteresis loops of both samples shift approach p/p0 ¼1, suggesting the existence of macropores, which agrees well with the poresize distribution curves (Fig. 2C)[9]. It can be seen from Fig. 2C that BWO sample contains small mesopores centered at 13.7 nm and large mesopores of around 37.1 nm. Whereas, EBWO sample possesses small mesopores with a peak around 16.1 nm and large mesopores of 36.2 nm. As revealed by SEM observation, the smaller pores may be generated during the crystal growth process, while the larger pores are ascribed to the space between the intercrossed Bi2WO6 plates. The BET specific surface areas of EBWO and BWO samples calculated from N2 isotherms are about 3.5 and 1.2 m2g, respectively. PL emission spectra are useful techniques in determining the separation efficiency of photogenerated electron-hole pairs in semiconductor. A low PL intensity indicates a low recombination rate of the electron-hole pairs under light irradiation. Fig. 2D shows comparison of PL spectra of the as-prepared samples. The PL intensity of EBWO is lower than that of BWO, which clearly suggests that the recombination of photogenerated electron-hole pairs is greatly inhibited in EBWO sample. The low PL intensity of EBWO may be mainly attributed to its nanoparticles comprising
Fig. 3. Photocatalytic degradation of RhB by EBWO and BWO samples.
Bi2WO6 nanoplates, whose small size and nanoplates-like structure are beneficial for the separation and transport of the photogenerated electron-hole pairs[10]. Fig. 3 illustrates the degradation of RhB by EBWO and BWO samples under identical conditions. It can be seen that the degradation efficiency over BWO photocatalyst is 35.6% after 120 min irradiation. While, the degradation efficiency over EBWO sample is 91.1%, about 2.6 times greater than that of BWO sample. It is well known that the photocatalytic activity of semiconductor is affected by many factors, such as crystal size, surface area, morphology and electronic structure, which can cooperate with
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Y. Liu et al. / Materials Letters 139 (2015) 401–404
each other and improve the photocatalytic activity. As far as EBWO sample is concerned, the high photocatalytic performance is due to the following reasons: (i) the larger surface area not only supplies more active sites and absorbs more organic pollutant but also facilitates the separation efficiency of the photogenerated electron-hole pairs in the degradation process, resulting in a high photocatalytic activity (ii) the porous structure provides more transport paths for the reactants to reach the reactive sites for photocatalytic reaction and make the reaction occur more efficiently and easily (iii) the nanoplates-like structure allows multiple reflections of visible light, which improves light-harvesting and increases the number of photoinduced electrons and holes available to participate in the photocatalytic reaction.
Bi2WO6 obtained without using albumin. The present work not only provides a simple, economical and environmentally friendly synthesis route to prepare Bi2WO6 nanoplates, but also presents a step forward in the design of other interesting materials with controllable morphology and improved performance.
Acknowledgments The authors gratefully acknowledge the financial support from the National Innovation Experiment Program for University Students (Grant no. 201310476056). References
4. Conclusion Well-dispersed Bi2WO6 nanoplates were successfully synthesized through an environmentally friendly route using albumin as a biotemplate. It was found that albumin used as gelling agent and stabilizer plays an important role in the formation of Bi2WO6 nanoplates. The photocatalytic activities of the as-prepared Bi2WO6 samples were evaluated by degradation of RhB under visible light irradiation. Due to the unique morphology, large surface area and porous structure, Bi2WO6 nanoplates exhibited higher shape-associated photocatalytic performance than that of
[1] [2] [3] [4] [5] [6] [7] [8] [9] [10]
Min Y, Zhang K, Chen Y, Zhang Y, Zhao W. Sep Purif Technol 2012;92:115–20. Kudo A, Hijii S. Chem Lett 1999;28:1103–4. Tang J, Zou Z, Ye J. Catal Lett 2004;92:53–6. Zhang G, Lü F, Li M, Yang J, Zhang X, Huang B. J Phys Chem Solids 2010;71:579–82. Zhu G, Liang J, Hojamberdiev M, Bilmes SA, Wei X, Liu P, et al. Mater Lett 2014;122:216–9. Hu Y, Ma Y, Zhou Y, Nie F, Duan X, Pei C. J Cryst Growth 2010;312:831–6. Maensiri S, Masingboon C, Laokul P, Jareonboon W, Promarak V, Anderson PL, et al. Cryst Growth Des 2007;7:950–5. Zhuo Y, Huang J, Cao L, Ouyang H, Wu J. Mater Lett 2013;90:107–10. Xu L, Yang X, Zhai Z, Hou W. Cryst Eng Commun 2011;13:7267–75. Zhang F-J, Xie F-Z, Liu J, Zhao W, Zhang K. Ultrason Sonochem 2013;20:209–15.
Contents lists available at ScienceDirect
Materials Letters journal homepage: www.elsevier.com/locate/matlet
Synthesis and characterization of Bi2WO6 nanoplates using egg white as a biotemplate through sol-gel method Yumin Liu n, Hua Lv, Jiayuan Hu, Zijin Li Collaborative Innovation Center of Henan Province for Green Manufacturing of Fine Chemicals, School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang, Henan 453007, P. R. China
art ic l e i nf o
a b s t r a c t
Article history: Received 5 August 2014 Accepted 24 October 2014 Available online 4 November 2014
Bi2WO6 nanoplates with thickness of about 100 nm had been successfully synthesized by sol-gel method using egg white proteins (albumin) as a biotemplate. On the basis of results of morphologies observation, it was found that albumin was critical for controlling the morphologies of the final products. Photocatalytic activities of the samples were evaluated by the degradation of Rhodamine B (RhB) under visible light irradiation. Due to the combined effects of high specific area, high light absorption and efficient separation of photogenerated electron-hole pairs, Bi2WO6 photocatalyst synthesized in the presence of albumin exhibited better photocatalytic activity than that Bi2WO6 synthesized without using albumin. & 2014 Elsevier B.V. All rights reserved.
Keywords: Bi2WO6 Albumin Semiconductors Sol-gel preparation
1. Introduction Bismuth tungstate (Bi2WO6), as one of the simplest numbers of Aurivillius oxide family of layered perovskite, is composed of accumulated layers of alternating fluorite-like (WO4)2- sheets and perovskite-like (Bi2O2)2 þ layers[1]. Since Kudo and Hijii firstly demonstrated the photocatalytic splitting water for O2 evolution over Bi2WO6[2], extensive attention had been paid to Bi2WO6 for its potential applications in solar-energy-transfer and photocatalytic fields. However, the practical applications of Bi2WO6 have been strictly limited due to its relatively low photocatalytic activity. To improve the photocatalytic activity of Bi2WO6, various methods, such as solid-state reaction[3], sol-gel process[4], hydrothermal and solvothermal method[1,5], have been reported to synthesize Bi2WO6 with various morphologies and architectures. As for sol-gel method, the gelata plays an important role in the mineralization for controlling the structure, morphology and diameter size of the final products. Egg white proteins (albumin) contain more than 20 amino acids and are well known for the high nutrition quality[6]. Besides that, egg white has been widely used as a binder cum gel forming material because of its high solubility in water and having the ability to associate with metal ions in solution. For example, Hu et al. have prepared the stack-like crystallization of calcium carbonate using egg white as a gelata [6]. The platelike clusters of CeO2 nanoparticles with particle size of 6-30 nm have been successfully prepared in the presence of
n
Corresponding author. Tel.: þ 86 373 3326335; fax: þ 86 373 3326336. E-mail address: [email protected] (Y. Liu).
http://dx.doi.org/10.1016/j.matlet.2014.10.131 0167-577X/& 2014 Elsevier B.V. All rights reserved.
freshly extracted egg white[7]. Inspired by the above efforts, we herein present a simple, innovative and environment friendly approach for the synthesis of Bi2WO6 nanoplates using egg white proteins as a gelata through sol-gel method. In addition, the enhanced photocatalytic activity for Bi2WO6 nanoplates was also systematically investigated.
2. Experimental 2.1. Materials and synthesis In a typical procedure, the freshly extracted egg white (5 ml) was mixed with 25 ml deionized water under stirring until a homogeneous solution was obtained. Then, 0.6 mmol of Bi (NH3)2C6H7O7 H2O and 0.043 mmol of (NH4)6W7O24 6 H2O were slowly added to the egg white solution to obtain a well-dissolved solution. The as-formed transparent mixture solution was evaporated at 80 oC in the air until the formation of yellow sticky gelatin. The gelatin was dried in the oven at 80 oC for the whole night and then calcined in a muffle furnace at 500 oC for 2 h to obtain the Bi2WO6 nanoplates (denoted as EBWO). For comparison, Bi2WO6 sample was also synthesized by replacing the egg white solution with an equal volume of deionized water (denoted as BWO), while the other experimental conditions remained the same. 2.2. Characterization The crystal structure of the samples was determined by XRD (Bruker D8 Advance, Germany) using graphite monochromatic
402
Y. Liu et al. / Materials Letters 139 (2015) 401–404
copper radiation (Cu Kα). Morphologies and structures of the samples were observed by SEM (JEOL JSM-63901, Japan) and TEM (JEOL JEM-2100, Japan). The Brunauer-Emmett-Teller (BET) specific surface area was determined on a Surface Area Analyzer (NOVA2000e, USA) at liquid nitrogen temperature. The optical absorption spectra of samples were recorded by UV–vis diffuse reflectance spectra (Cary5000 UV–vis-NIR) using BaSO4 as a reference. Photoluminescence (PL) spectra were measured by using a Fluorescence Spectrophotometer (FP-6500, Japan) equipped with a Xenon lamp at an excitation wavelength of 300 nm. 2.3. Photocatalytic test Typically, 0.1 g catalyst (EBWO or BWO) was added into 100 ml RhB aqueous solution (5 mg L-1). After ultrasonic dispersion for 10 min, the suspension was then stirred for 30 min in the dark to reach the adsorption-desorption equilibrium. Then, the solution was exposed to simulated visible light irradiation using a 300 W Xe lamp. At given time intervals, about 5 ml of the suspension was collected for further analysis after centrifugation. The concentration of RhB was determined using UV–vis spectrophotometer at λmax of 553 nm. 3. Results and discussion The structure and morphology of the as-prepared Bi2WO6 were characterized by XRD, SEM and TEM. As shown in Fig. 1A, all the diffraction peaks of Bi2WO6 samples synthesized with and without albumin match well with the pure orthorhombic phase of Bi2WO6 (card no. 39-0256), and no characteristic peaks for impurities can
be detected. Moreover, the BWO sample exhibits higher intensity and narrower diffraction peaks than that of EBWO sample, indicating that the existence of albumin can decrease the crystalline grain growth and consequently result in small crystal size. The average crystal sizes of BWO and EBWO samples are 37.3 nm and 32.6 nm, respectively, using FWHM of (1 1 3) diffraction peak at 28.8o with the famous Scherrer equation. A panoramic SEM image (Fig. 1B) indicates that BWO sample is almost entirely composed of large quantities of irregular block particles and agglomerated plates. While, EBWO sample (Fig. 1C and Fig. 1D) exhibits well dispersed nanoplates-like morphology with thickness of ~100 nm and the other two dimensions of several micrometers. The interplanar spacing of EBWO sample (inset of Fig. 1D) is determined to be 0.273 nm, corresponding to d spacing of (0 2 0) plane of orthorhombic Bi2WO6. Compared to BWO sample, we believe that albumin used as gelling agent and stabilizer is critical for the formation of nanoplates Bi2WO6, which may adsorb onto surfaces of the nucleating Bi2WO6 to regulate the lamellar growth and inhibit the agglomerate tendency of the growing plates during the preparing process. The optical properties of as-prepared Bi2WO6 samples were measured by UV–vis diffuse reflectance spectroscopy. As shown in Fig. 2A, both samples have a broad absorption from the UV light to visible light region due to the band gap transition. It is noteworthy that EBWO sample exhibits an enhanced optical absorption in the visible light region compared to BWO sample. After the calculation [8], the band gaps (Eg) of EBWO and BWO samples are estimated to be about 2.83 eV and 3.04 eV from the onsets of the absorption edges (inset of Fig. 2A), respectively. Taking the efficient utilization of visible light into account, we believe that EBWO sample, with long wavelength absorption band and enhanced absorption in the
Fig. 1. (A) XRD pattern. (B) SEM image of BWO. (C) SEM image of EBWO (Inset is the magnified image). (D) TEM image of EBWO (Inset is the corresponding HRTEM image).
Y. Liu et al. / Materials Letters 139 (2015) 401–404
403
Fig. 2. (A) UV–vis diffuse reflectance spectra and the corresponding (αhv)2 vs (hv) curves (inset) of samples. (B) N2 adsorption-desorption isotherms and (C) pore-size distribution curves of samples. (D) PL spectrum of samples.
visible light region, is an efficient photocatalyst for decomposition of organic contaminants under visible light irradiation. Fig. 2B shows the nitrogen adsorption/desorption isotherms of EBWO and BWO samples. These isotherms can be classified to type IV with H3-type hysteresis loops at high relative pressures, indicating the characteristic of mesoporous feature. These porous structures can be ascribed to the irregular stacking of Bi2WO6 plates which give rise to slit-shaped pores. Moreover, the hysteresis loops of both samples shift approach p/p0 ¼1, suggesting the existence of macropores, which agrees well with the poresize distribution curves (Fig. 2C)[9]. It can be seen from Fig. 2C that BWO sample contains small mesopores centered at 13.7 nm and large mesopores of around 37.1 nm. Whereas, EBWO sample possesses small mesopores with a peak around 16.1 nm and large mesopores of 36.2 nm. As revealed by SEM observation, the smaller pores may be generated during the crystal growth process, while the larger pores are ascribed to the space between the intercrossed Bi2WO6 plates. The BET specific surface areas of EBWO and BWO samples calculated from N2 isotherms are about 3.5 and 1.2 m2g, respectively. PL emission spectra are useful techniques in determining the separation efficiency of photogenerated electron-hole pairs in semiconductor. A low PL intensity indicates a low recombination rate of the electron-hole pairs under light irradiation. Fig. 2D shows comparison of PL spectra of the as-prepared samples. The PL intensity of EBWO is lower than that of BWO, which clearly suggests that the recombination of photogenerated electron-hole pairs is greatly inhibited in EBWO sample. The low PL intensity of EBWO may be mainly attributed to its nanoparticles comprising
Fig. 3. Photocatalytic degradation of RhB by EBWO and BWO samples.
Bi2WO6 nanoplates, whose small size and nanoplates-like structure are beneficial for the separation and transport of the photogenerated electron-hole pairs[10]. Fig. 3 illustrates the degradation of RhB by EBWO and BWO samples under identical conditions. It can be seen that the degradation efficiency over BWO photocatalyst is 35.6% after 120 min irradiation. While, the degradation efficiency over EBWO sample is 91.1%, about 2.6 times greater than that of BWO sample. It is well known that the photocatalytic activity of semiconductor is affected by many factors, such as crystal size, surface area, morphology and electronic structure, which can cooperate with
404
Y. Liu et al. / Materials Letters 139 (2015) 401–404
each other and improve the photocatalytic activity. As far as EBWO sample is concerned, the high photocatalytic performance is due to the following reasons: (i) the larger surface area not only supplies more active sites and absorbs more organic pollutant but also facilitates the separation efficiency of the photogenerated electron-hole pairs in the degradation process, resulting in a high photocatalytic activity (ii) the porous structure provides more transport paths for the reactants to reach the reactive sites for photocatalytic reaction and make the reaction occur more efficiently and easily (iii) the nanoplates-like structure allows multiple reflections of visible light, which improves light-harvesting and increases the number of photoinduced electrons and holes available to participate in the photocatalytic reaction.
Bi2WO6 obtained without using albumin. The present work not only provides a simple, economical and environmentally friendly synthesis route to prepare Bi2WO6 nanoplates, but also presents a step forward in the design of other interesting materials with controllable morphology and improved performance.
Acknowledgments The authors gratefully acknowledge the financial support from the National Innovation Experiment Program for University Students (Grant no. 201310476056). References
4. Conclusion Well-dispersed Bi2WO6 nanoplates were successfully synthesized through an environmentally friendly route using albumin as a biotemplate. It was found that albumin used as gelling agent and stabilizer plays an important role in the formation of Bi2WO6 nanoplates. The photocatalytic activities of the as-prepared Bi2WO6 samples were evaluated by degradation of RhB under visible light irradiation. Due to the unique morphology, large surface area and porous structure, Bi2WO6 nanoplates exhibited higher shape-associated photocatalytic performance than that of
[1] [2] [3] [4] [5] [6] [7] [8] [9] [10]
Min Y, Zhang K, Chen Y, Zhang Y, Zhao W. Sep Purif Technol 2012;92:115–20. Kudo A, Hijii S. Chem Lett 1999;28:1103–4. Tang J, Zou Z, Ye J. Catal Lett 2004;92:53–6. Zhang G, Lü F, Li M, Yang J, Zhang X, Huang B. J Phys Chem Solids 2010;71:579–82. Zhu G, Liang J, Hojamberdiev M, Bilmes SA, Wei X, Liu P, et al. Mater Lett 2014;122:216–9. Hu Y, Ma Y, Zhou Y, Nie F, Duan X, Pei C. J Cryst Growth 2010;312:831–6. Maensiri S, Masingboon C, Laokul P, Jareonboon W, Promarak V, Anderson PL, et al. Cryst Growth Des 2007;7:950–5. Zhuo Y, Huang J, Cao L, Ouyang H, Wu J. Mater Lett 2013;90:107–10. Xu L, Yang X, Zhai Z, Hou W. Cryst Eng Commun 2011;13:7267–75. Zhang F-J, Xie F-Z, Liu J, Zhao W, Zhang K. Ultrason Sonochem 2013;20:209–15.