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Superior adsorption and photoinduced carries transfer behaviors of dandelion-shaped Bi 2 S 3 @MoS 2 : experiments and theory

View Article: PubMed Central - PubMed

ABSTRACT

The enhanced light-harvesting capacity and effective separation of photogenerated carriers in fantastic hierarchical heterostructures enjoy striking attention for potential applications in the field of solar cells and photocatalysis. A three-dimensional (3D) dandelion-shaped hierarchical Bi2S3 microsphere compactly decorated with wing-shaped few layered MoS2 lamella (D-BM) was fabricated via a facile hydrothermal self-assembly process. Especially, polyethylene glycol (PEG) has been proven as the vital template to form D-BM microsphere. Importantly, the as-prepared D-BM microsphere presents pH-dependent superior adsorption behavior and remarkable visible light photocatalytic activity for degradation of organic dyestuffs (Rhodamine B/RhB and Methylene blue/MB), far exceeding those for the pure Bi2S3 and MoS2. It is understandable that D-BM with high surface area possesses more active sites and promotes light utilization due to the unique porous structure with outspread wings. Besides, based on the experiments and theoretical calculations, the staggered type II band alignment of D-BM permits the charge injection from Bi2S3 to MoS2, subsequently accelerates the separation and restrains the recombination of carriers, leading to excellent photocatalytic activity, as well as the photoconductance and photoresponse performance (with Ilight/Idark ratio 567).

No MeSH data available.


(a,b) SEM images of the dandelion-shaped Bi2S3 microspheres under different magnifications. The inset shows the high magnification SEM image of vimineous Bi2S3 nanorods. (c) The broken Bi2S3 microspheres. (d) SEM image of MoS2 nanoflower and the inset is the several chapped MoS2 nanoflowers. (e,f) SEM image with different magnifications of the synthesized D-BM heterostructures. The insets are a local amplification from the side views and a broken section.
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f2: (a,b) SEM images of the dandelion-shaped Bi2S3 microspheres under different magnifications. The inset shows the high magnification SEM image of vimineous Bi2S3 nanorods. (c) The broken Bi2S3 microspheres. (d) SEM image of MoS2 nanoflower and the inset is the several chapped MoS2 nanoflowers. (e,f) SEM image with different magnifications of the synthesized D-BM heterostructures. The insets are a local amplification from the side views and a broken section.

Mentions: The morphology and micro-structure of all the samples have been investigated by SEM images. Figure 2a,b display the pure D-Bi2S3 microspheres in different magnifications. It can be seen that the Bi2S3 structures are distributed in the shape of irregular microspheres with the average diameter of 5 μm. Apparently (inset of Fig. 2b), these D-Bi2S3 micropheres were composed of a large number of acicular crystalline nanorods with uniform diameters of about 80 nm. Moreover, the broken D-Bi2S3 microsphere shown in Fig. 2c indicates that the acicular Bi2S3 nanorods radiate from the center and stack uniformly. It is extremely vital that the interstices between Bi2S3 nanorods can provide particular framework for the embedded of layered MoS2 petals. As presented in Fig. 2d, the pure MoS2 flowers reveal the diameter of 4 μm, with number of thinnish petals aggregated closely. The inset of Fig. 2d provides a chapped MoS2 flowers, and it illustrates that these disordered petals grown from a common center to form the spherical structure. Figure 2e exhibits the morphology of the hydrothermal synthesized D-BM (5 MBS) hetero-microspheres. Detailedly, some other SEM information on Bi2S3, MoS2, and hybrids are shown in Figs S1 and S2 (ESI). Generally, the whole D-Bi2S3 microspheres are uniformly covered with 2D MoS2 nanosheets. A high magnification top view SEM image shown in the inset of Fig. 2e, the composites present apparent differences from the pristine D-Bi2S3 or MoS2. Iconically, almost each Bi2S3 nanorod are compactly decorated with a pair of expanding wings of MoS2 nanosheets, thus forming the MoS2 coated Bi2S3 heterostructure. In the inset of Fig. 2f, a section of the broken composites elucidates that MoS2 nanosheets have grown along the Bi2S3 nanorods and deeply rooted in the center of Bi2S3 spheres, which expects that this unique hierarchical architecture can provide more effective activity sites and enhance the photoelectric properties.


Superior adsorption and photoinduced carries transfer behaviors of dandelion-shaped Bi 2 S 3 @MoS 2 : experiments and theory
(a,b) SEM images of the dandelion-shaped Bi2S3 microspheres under different magnifications. The inset shows the high magnification SEM image of vimineous Bi2S3 nanorods. (c) The broken Bi2S3 microspheres. (d) SEM image of MoS2 nanoflower and the inset is the several chapped MoS2 nanoflowers. (e,f) SEM image with different magnifications of the synthesized D-BM heterostructures. The insets are a local amplification from the side views and a broken section.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC5304175&req=5

f2: (a,b) SEM images of the dandelion-shaped Bi2S3 microspheres under different magnifications. The inset shows the high magnification SEM image of vimineous Bi2S3 nanorods. (c) The broken Bi2S3 microspheres. (d) SEM image of MoS2 nanoflower and the inset is the several chapped MoS2 nanoflowers. (e,f) SEM image with different magnifications of the synthesized D-BM heterostructures. The insets are a local amplification from the side views and a broken section.
Mentions: The morphology and micro-structure of all the samples have been investigated by SEM images. Figure 2a,b display the pure D-Bi2S3 microspheres in different magnifications. It can be seen that the Bi2S3 structures are distributed in the shape of irregular microspheres with the average diameter of 5 μm. Apparently (inset of Fig. 2b), these D-Bi2S3 micropheres were composed of a large number of acicular crystalline nanorods with uniform diameters of about 80 nm. Moreover, the broken D-Bi2S3 microsphere shown in Fig. 2c indicates that the acicular Bi2S3 nanorods radiate from the center and stack uniformly. It is extremely vital that the interstices between Bi2S3 nanorods can provide particular framework for the embedded of layered MoS2 petals. As presented in Fig. 2d, the pure MoS2 flowers reveal the diameter of 4 μm, with number of thinnish petals aggregated closely. The inset of Fig. 2d provides a chapped MoS2 flowers, and it illustrates that these disordered petals grown from a common center to form the spherical structure. Figure 2e exhibits the morphology of the hydrothermal synthesized D-BM (5 MBS) hetero-microspheres. Detailedly, some other SEM information on Bi2S3, MoS2, and hybrids are shown in Figs S1 and S2 (ESI). Generally, the whole D-Bi2S3 microspheres are uniformly covered with 2D MoS2 nanosheets. A high magnification top view SEM image shown in the inset of Fig. 2e, the composites present apparent differences from the pristine D-Bi2S3 or MoS2. Iconically, almost each Bi2S3 nanorod are compactly decorated with a pair of expanding wings of MoS2 nanosheets, thus forming the MoS2 coated Bi2S3 heterostructure. In the inset of Fig. 2f, a section of the broken composites elucidates that MoS2 nanosheets have grown along the Bi2S3 nanorods and deeply rooted in the center of Bi2S3 spheres, which expects that this unique hierarchical architecture can provide more effective activity sites and enhance the photoelectric properties.

View Article: PubMed Central - PubMed

ABSTRACT

The enhanced light-harvesting capacity and effective separation of photogenerated carriers in fantastic hierarchical heterostructures enjoy striking attention for potential applications in the field of solar cells and photocatalysis. A three-dimensional (3D) dandelion-shaped hierarchical Bi2S3 microsphere compactly decorated with wing-shaped few layered MoS2 lamella (D-BM) was fabricated via a facile hydrothermal self-assembly process. Especially, polyethylene glycol (PEG) has been proven as the vital template to form D-BM microsphere. Importantly, the as-prepared D-BM microsphere presents pH-dependent superior adsorption behavior and remarkable visible light photocatalytic activity for degradation of organic dyestuffs (Rhodamine B/RhB and Methylene blue/MB), far exceeding those for the pure Bi2S3 and MoS2. It is understandable that D-BM with high surface area possesses more active sites and promotes light utilization due to the unique porous structure with outspread wings. Besides, based on the experiments and theoretical calculations, the staggered type II band alignment of D-BM permits the charge injection from Bi2S3 to MoS2, subsequently accelerates the separation and restrains the recombination of carriers, leading to excellent photocatalytic activity, as well as the photoconductance and photoresponse performance (with Ilight/Idark ratio 567).

No MeSH data available.