Bismuth selenide (Bi2Se3) nanosheets, a member of the AV-BVI (A = Sb, Bi, B = S, Se, Te) family of metal chalcogenide semiconductor materials, have a large surface area, a tunable bandgap that is ...dependent on the thickness of the atomic layer, and potential applications in photocatalysis, photothermal therapy, and photodetectors, among other fields. Here, we describe the synthesis of Bi2Se3 nanosheets using a simple solvothermal method, resulting in a smooth surface and a well-crystalline structure. The XRD results indicate that the Bi2Se3 nanosheets belong to the hexagonal crystal structure, with lattice constants of a = 0.4140 nm, b = 0.4140 nm, and c = 2.8636 nm. Bi2Se3 nanosheet photodetectors, which have a Schottky contact between the nanosheets and the electrodes, exhibit a notable light response to an 850 nm laser. The device displays a switch ratio of 50 when operated at a voltage of 0.6 V and an irradiance of 2.87 W/cm2 (@ 850 nm). The switching speed of the device was measured in terms of rise and decay times, measured to be 126 ms and 85 ms respectively. It is evident from the obtained results that high performance nanoscale photodetectors can be made efficiently from 2D Bi2Se3 nanosheets.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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•Inversion of bulk states due to spin-orbit coupling.•Surface Dirac states formed by Bi atoms in the first quintuple layer.•Appearance of additional p surface states due to BiSe ...subsurface substitution.
We present a systematic theoretical study of bismuth selenide electronic structure in the presence of spin-orbit interaction. It is confirmed that the inversion of Bi pz and Se pz states in the bulk band structure is induced by spin-orbit coupling. The energy gap in the bulk electronic structure is closed by pz states associated mainly with Bi atoms from the first quintuple layer. We elucidate the influence of Bi substitution in the fifth atomic layer on the local density of electronic states in the top quintuple layer. Finally, we describe how it develops into the additional p states in the surface electronic structure, which produce the triangular protrusion observed in Scanning Tunnelling Microscopy measurements and characteristic narrow features in Scanning Tunnelling Spectroscopy results.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Bi, a high atomic number element, has a high photoelectric absorption coefficient, and Se has anticancer activity. Hence, their compound chalcogenide (Bi2Se3) deserves a thorough investigation for ...biomedical applications. This study reveals that Bi2Se3 nanoplates (54 nm wide) protected with poly(vinylpyrollidone) (PVP) could be presumed to have low toxicity even at a high dose of 20 mg/kg in mice. This conclusion is made through studies on the biodistribution and 90‐day long term in vivo clearance of the nanoplates. The liver and spleen are dominant organs for accumulation of the nanoplates, which is mainly due to RES absorption. 93% of the nanoplates are cleared after 90 days of treatment. Concentrations of Bi and Se in tumor tissue continuously increased until 72 h after intraperitoneal injection into mice. Such selective accumulation of Bi is utilized to enhance the contrast of X‐ray computerized tomography (CT) images. Bi element concentrated in a tumor leads to damage on the tumor cells when exposed to gamma radiation. Growth of the tumor is significantly delayed and stopped in 16 days after the tumor is treated by radiation with Bi2Se3 nanoplates. This work clearly shows that Bi2Se3 nanoplates may be used for cancer radiation therapy and CT imaging. The nanoplates deserve further study for biological and medical applications.
The Bi2Se3 nanoplates for cancer radiation therapy are designed. 50 nm PVP‐protected Bi2Se3 nanoplates induce long blood circulation. The Bi2Se3 nanoplates are metabolizable and show low in vivo toxicity. The tumor accumulation of the Bi2Se3 nanoplates exhibit strong enhancement of cancer radiotherapy.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Poly(vinylpyrrolidone)-encapsulated Bi2 Se3 nanosheets with a thickness of 1.7 nm and diameter of 31.4 nm are prepared by a solution method. Possessing an extinction coefficient of 11.5 L g(-1) ...cm(-1) at 808 nm, the ultrathin Bi2 Se3 nanosheets boast a high photothermal conversion efficiency of 34.6% and excellent photoacoustic performance. After systemic administration, the Bi2 Se3 nanosheets with the proper size and surface properties accumulate passively in tumors enabling efficient photoacoustic imaging of the entire tumors to facilitate photothermal cancer therapy. In vivo biodistribution studies reveal that they are expelled from the body efficiently after 30 d. The ultrathin Bi2 Se3 nanosheets have large clinical potential as metabolizable near-infrared-triggered theranostic agents.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
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Photothermal therapy (PTT) has gained widespread attention due to its significant advantages, such as noninvasiveness and ability to perform laser localization. However, PTT usually ...reaches temperatures exceeding 50 °C, which causes tumor coagulation necrosis and unfavorable inflammatory reactions, ultimately decreasing its efficacy. In this study, multifunctional two-dimensional Bi2Se3 nanodisks were synthesized as noninflammatory photothermal agents for glioma therapy. The Bi2Se3 nanodisks showed high photothermal stability and biocompatibility and no apparent toxicology. In addition, in vitro and in vivo studies revealed that the Bi2Se3 nanodisks effectively ablated gliomas at relatively low concentrations and inhibited tumor proliferation and migration. Moreover, the multienzymatic activity of the Bi2Se3 nanodisks inhibited the PTT-induced inflammatory response through their high ability to scavenge reactive oxygen species. Finally, the Bi2Se3 nanodisks demonstrated computed tomography capabilities for integrating diagnosis and treatment. These findings suggest that multifunctional Bi2Se3 nanodisk nanozymes can enable more effective cancer therapy and noninflammatory PTT.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The development of nanotheranostic agent with imaging-guided highly therapeutic efficiency has attracted most attentions on tumor treatment. Herein, the novel MoSe2/Bi2Se3 nanosheets were designed to ...integrate CT/photothermal (PT) imaging and photodynamic/photothermal/chemo-therapy (PTT/PDT/chemotherapy) into one nanoplatform. Firstly, the MoSe2 nanosheets (5–30 nm) were prepared via ultrasound-assisted exfoliated method, and then by a cation-exchange strategy the novel sandwich nanostructure Bi2Se3/MoSe2/Bi2Se3 (Bi-M-3) were obtained, revealing the narrower band gap (1.17 eV) and the stronger near-infrared (NIR) absorption. Both experimental and density functional theory (DFT) calculations reveal the Z-scheme mechanism of charge transfer in the heterostructure, which induces the enhanced ROS (⋅OH) generation due to the efficient separation of photogenerated electron-hole pairs. Meanwhile, the nanoheterostructure also makes sure the improved photothermal conversion efficiency (59.3%). Besides, we also found the photothermal effect can promote the transfer photo-generated electron that is in favor of ROS generation. Furthermore, because of the higher absorption coefficient of X-ray for Bi atom, the heterostructure also exhibits the higher CT imaging contrast than pure MoSe2 sample. After the loading of anticancer drug Doxorubicin (Dox), Bi-M-3@PEG-Dox displays the acid/photothermal sensitive drug release behavior. The synergistic effect of chemotherapy, photodynamic and photothermal therapy further induces the superior cancer cell apoptosis and enhanced antitumor effect.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Abundant photo-generated electrons/thermally excited electrons are rapidly transferred from Bi2Se3 to BiOCl via the electron transport channels formed by interface oxygen vacancies under the synergy ...of interface/thermal electric field, and thus OTC was effectively mineralizing to CO2 and H2O under the cooperation of ·O2-and h+.
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•Big surface area benefits the mass transfer and adsorption of OTC.•Electron transfer channels promote the transport of thermal/photo-generated electrons.•Interface/thermal electric field boosting the carrier transfer efficiency.
Ameliorating photocatalytic performance by enhancing carrier transport efficiency is an appealing strategy. Thus, Bi2Se3/BiOCl heterostructure with appropriate oxygen vacancies (OVs) was successfully fabricated by using of ultrasound approach. The results discern that BOC-2 can degrade 81 % Oxytetracycline hydrochloride (OTC, 20 mg/L) within 3 h, which is 3.46 and 5.71 times higher than BiOCl and Bi2Se3, respectively. Mechanism studies verified that abundant photo-generated electrons/thermally excited electrons are quickly transferred from Bi2Se3 to BiOCl via the electron transport channels formed by interface oxygen vacancies (IOVs) under the synergy of interface/thermal electric field, and thus OTC was effectively mineralizing to CO2 and H2O under the cooperation of ·O2– (65.71 %) and h+ (26.33 %). Meanwhile, the contribution of the interface/thermal electric field to photocatalytic activity was firstly established. Moreover, the pollutant degradation pathways and the intermediates toxicity were systematically researched by DFT theoretical calculations and experiments. This work offers an innovation strategy to mend photocatalytic activity by boosting carrier transport efficiency under the collaborative of interface/thermal electric field.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Binary compound bismuth selenide (Bi2Se3) in the orthorhombic phase is an n-type semiconductor with optoelectronic properties desirable for applications in photosensitive devices. Obtaining this ...phase at room temperature is challenging, resulting in limited literature on the subject, thereby restricting the available information about this phase. In this study, we present our findings on the aqueous medium synthesis and stability of nanocrystalline Bi2Se3 thin films over a Si substrate, predominantly exhibiting an orthorhombic phase (>92%), utilizing the electrodeposition technique. By changing the concentration of the electrolyte and deposition potential, it was possible to modify the morphology, absorbance, optical gap, and the magnitude of photocurrent signal in the photoelectrochemical cell (PEC), with no dramatical change in the chemical composition and crystalline phase of the films. The samples presented an inverse correlation between crystallite size and band gap, associated with the deposition conditions. Stability in the transient photocurrent signal with amplitudes around 9 µA/cm2 at 0.30 VSCE was observed for the sample growth at more negative potential.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
3D hierarchical G-Bi2Se3/C is synthesized and directly used as a self-supporting anode in Li/Na-ion batteries. The synergistic effects of nanostructured Bi2Se3 and high conductive rGO coating layer ...and carbon fiber substrate enable good cycling stability and excellent rate capability.
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•Self-supporting G-Bi2Se3/C anode is synthesized via CVD for Li+/Na+ storage.•The synergistic effects enable structural stability and fast reaction kinetics.•Good cycling stability and high rate capability are achieved in Li/Na-ion battery.•An advanced structural design principle for high-performance anode materials.
Bi2Se3 is a promising material for anodes in lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs) due to its abundance, easy preparation, and high capacity. However, its practical application is hindered by low conductivity and significant volume variation during cycling, leading to poor rate capability and cycling stability. Herein, a novel composite consisting of Bi2Se3 nanoplates deposited on carbon cloth (CC) and encapsulated by reduced graphene oxide (rGO) has been designed and synthesized. The composite structure combines the advantages of the Bi2Se3 nanoplates, CC substrate, and rGO encapsulation, leading to enhanced electrochemical properties. The physical vapor deposition of Bi2Se3 nanoplates onto CC ensures a high loading of active material, while the rGO encapsulation provides a conductive and stable framework for the composite. This synergistic design allows for improved electron and ion transport, as well as efficient accommodation of the volume changes during cycling. In LIBs, the composite demonstrates a high reversible capacity of 467.5 mAh/g at 0.1 A/g after 120 cycles. Moreover, it displays an outstanding rate capability, delivering a capacity of 398.6 mAh/g at 5.0 A/g. Similarly, in SIBs, the composite maintains a reversible capacity of 375.3 mAh/g at 0.1 A/g over 100 cycles and exhibits a high-rate capacity of 286.3 mAh/g at 5.0 A/g. This work represents a significant step forward in addressing the challenges associated with Bi2Se3 as an anode material, paving the way for the development of high-performance LIBs and SIBs.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
•Pomegranate-like Bi2Se3@C was synthesized by a sample solvothermal methods.•Bi2Se3@C delivers a high volume specific capacity as anode for LIBs.•Ex-situ XRD demonstrates the phase transition of ...Bi2Se3@C during the cycle.•DFT shows that the heterostructure accelerate electron transfer and ion adsorption.
Lithium-ion batteries (LIBs) with high volume specific capacity have promising applications in small/microelectronics. However, the contradiction between Li+ diffusion kinetics and material compaction density severely restricts its development. The layered bismuth selenide (Bi2Se3) with high conductivity and compaction density is a candidate material for LIBs with high volume specific capacity. In this work, Bi2Se3@C was synthesized by solvothermal and selenization methods, and the final product exhibits a high specific capacity (468 mAh g−1 at 0.1 A g−1, corresponding to 1862 mAh cm−3) and good cycling stability (358 mAh g−1 after 500 cycles at 0.5 A g−1, corresponding to 1445 mAh cm−3). The excellent electrochemical performance results from the special morphology of the carbon layer-coated Bi2Se3 nanospheres, and the carbon layer not only regulates the volume expansion of Bi2Se3 during cycling but also improves the electronic conductivity, which is also confirmed by density functional theory calculation. Ex-situ X-ray diffraction spectrum reveals that the crystal phase of Bi2Se3 changed from hexagon to orthogonal after the initial cycle.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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