Enhanced Photocurrent of the Ag Interfaced Topological Insulator Bi2Se3 under UV- and Visible-Light Radiations

Bi2Se3 is a topological quantum material that is used in photodetectors, owing to its narrow bandgap, conductive surface, and insulating bulk. In this work, Ag@Bi2Se3 nanoplatelets were synthesized on Al2O3(100) substrates in a two-step process of thermal evaporation and magnetron sputtering. X-ray diffractometer (XRD), high-resolution transmission electron microscopy (HRTEM), Raman spectroscopy, and x-ray photoelectron spectroscopy (XPS) revealed that all samples had the typical rhombohedral Bi2Se3. Field-emission scanning electron microscopy (FESEM)-energy dispersive x-ray spectroscopy (EDS), XPS, and HRTEM confirmed the presence of the precipitated Ag. The optical absorptance of Bi2Se3 nanoplatelets in UV-visible range decreased with the Ag contents. Results of photocurrent measurements under zero-bias conditions revealed that the deposited Ag affected photosensitivity. A total of 7.1 at.% Ag was associated with approximately 4.25 and 4.57 times higher photocurrents under UV and visible light, respectively, than 0 at.% Ag. The photocurrent in Bi2Se3 at 7.1 at.% Ag under visible light was 1.72-folds of that under UV light. This enhanced photocurrent is attributable to the narrow bandgap (~0.35 eV) of Bi2Se3 nanoplatelets, the Schottky field at the interface between Ag and Bi2Se3, the surface plasmon resonance that is caused by Ag, and the highly conductive surface that is formed from Ag and Bi2Se3. This work suggests that the appropriate Ag deposition enhances the photocurrent in, and increases the photosensitivity of, Bi2Se3 nanoplatelets under UV and visible light.

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Zinc Oxide Nanoparticles from Waste Zn-C Battery via Thermal Route: Characterization and Properties

Nanomaterials ◽

10.3390/nano8090717 ◽

2018 ◽

Vol 8 (9) ◽

pp. 717 ◽

Cited By ~ 9

Author(s):

Rifat Farzana ◽

Ravindra Rajarao ◽

Pravas Behera ◽

Kamrul Hassan ◽

Veena Sahajwalla

Keyword(s):

Electron Microscopy ◽

Zno Nanoparticles ◽

Photoelectron Spectroscopy ◽

Uv Light ◽

Inert Atmosphere ◽

Bet Surface Area ◽

Visible Range ◽

Tem Analysis ◽

Thermal Synthesis ◽

X Ray

Disposable batteries are becoming the primary sources of powering day-to-day gadgets and consequently contributing to e-waste generation. The emerging e-waste worldwide is creating concern regarding environmental and health issues. Therefore, a sustainable recycling approach of spent batteries has become a critical focus. This study reports the detail characterization and properties of ZnO nanoparticles recovered from spent Zn-C batteries via a facile thermal synthesis route. ZnO nanoparticles are used in many applications including energy storage, gas sensors, optoelectronics, etc. due to the exceptional physical and optical properties. A thermal treatment at 900 °C under an inert atmosphere of argon was applied to synthesize ZnO nanoparticles from a spent Zn-C battery using a horizontal quartz tube furnace. X-ray diffraction (XRD), selected area electron diffraction (SAED) and X-ray photoelectron spectroscopy (XPS) results confirmed the formation of crystalline ZnO nanoparticles. Field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) analysis confirmed that the size of synthesised ZnO particles were less than 50 nm and mainly composed of sphere shaped nanoparticles. Synthesized ZnO exhibited BET surface area of 9.2629 m2/g and showed absorption of light in the UV region. Excitation of ZnO by UV light showed photoluminescence in the visible range. This study will create an opportunity for potential applications of ZnO nanoparticles from spent batteries and will benefit the environment by reducing the volume of e-waste in landfills.

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ROOM TEMPERATURE PHOTOLUMINESCENCE OF POLYCRYSTALLINE SIC PREPARED FROM CARBON-SATURATED SI MELT

International Journal of Modern Physics B ◽

10.1142/s021797920201083x ◽

2002 ◽

Vol 16 (06n07) ◽

pp. 1047-1051

Author(s):

JIANPING MA ◽

ZHIMING CHEN ◽

GANG LU ◽

MINGBIN YU ◽

LIANMAO HANG ◽

...

Keyword(s):

Electron Microscopy ◽

Photoelectron Spectroscopy ◽

Room Temperature ◽

Uv Light ◽

X Ray Diffraction ◽

X Ray ◽

Room Temperature Photoluminescence ◽

Composition And Structure ◽

Light Excitation ◽

Scanning Electron

Intense photoluminescence (PL) has been observed at room temperature from the polycrystalline SiC samples prepared from carbon-saturated Si melt at a temperature ranging from 1500 to 1650°C. Composition and structure of the samples have been confirmed by means of X-ray photoelectron spectroscopy, X-ray diffraction and scanning electron microscopy. PL measurements with 325 nm UV light excitation revealed that the room temperature PL spectrum of the samples consists of 3 luminescent bands, the peak energies of which are 2.38 eV, 2.77 eV and 3.06 eV, respectively. The 2.38 eV band is much stronger than the others. It is suggested that some extrinsic PL mechanisms associated with defect or interface states would be responsible to the intensive PL observed at room temperature.

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Synthesis of Hollow Flower-Like Fe3O4/MnO2/Mn3O4 Magnetically Separable Microspheres with Valence Heterostructure for Dye Degradation

Catalysts ◽

10.3390/catal9070589 ◽

2019 ◽

Vol 9 (7) ◽

pp. 589 ◽

Cited By ~ 4

Author(s):

Mingliang Ma ◽

Yuying Yang ◽

Yan Chen ◽

Fei Wu ◽

Wenting Li ◽

...

Keyword(s):

Electron Microscopy ◽

Visible Light ◽

Photoelectron Spectroscopy ◽

Organic Contaminants ◽

Dye Degradation ◽

Catalytic Performance ◽

X Ray ◽

Composite Microspheres ◽

Magnetically Separable ◽

Mno2 Nanosheet

In this manuscript, hollow flower-like ferric oxide/manganese dioxide/trimanganese tetraoxide (Fe3O4/MnO2/Mn3O4) magnetically separable microspheres were prepared by combining a simple hydrothermal method and reduction method. As the MnO2 nanoflower working as precursor was partially reduced, Mn3O4 nanoparticles were in situ grown from the MnO2 nanosheet. The composite microspheres were characterized in detail by employing scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Brunauer–Emmett–Teller (BET), vibration sample magnetometer (VSM) and UV–visible spectrophotometer (UV–vis). Under visible light conditions, the test for degrading rhodamine B (RhB) was used to verify the photocatalytic activity of the photocatalyst. The results showed that the efficiency of the Fe3O4/MnO2/Mn3O4 photocatalyst in visible light for 130 min is 94.5%. The catalytic activity of photocatalyst far exceeded that of the Fe3O4/MnO2 component, and after four cycles, the catalytic performance of the catalyst remained at 78.4%. The superior properties of the photocatalyst came from improved surface area, enhanced light absorption, and efficient charge separation of the MnO2/Mn3O4 heterostructure. This study constructed a green and efficient valence heterostructure composite that created a promising photocatalyst for degrading organic contaminants in aqueous environments.

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Photocatalytic degradation of deoxynivalenol over dendritic-like α-Fe2O3 under visible light irradiation

Toxins ◽

10.3390/toxins11020105 ◽

2019 ◽

Vol 11 (2) ◽

pp. 105 ◽

Cited By ~ 14

Author(s):

Huiting Wang ◽

Jin Mao ◽

Zhaowei Zhang ◽

Qi Zhang ◽

Liangxiao Zhang ◽

...

Keyword(s):

Electron Microscopy ◽

Visible Light ◽

Photocatalytic Degradation ◽

Visible Light Irradiation ◽

Photoelectron Spectroscopy ◽

High Performance ◽

Synthesis Method ◽

Light Irradiation ◽

Trichothecene Mycotoxin ◽

X Ray

Deoxynivalenol (DON) is a secondary metabolite produced by Fusarium, which is a trichothecene mycotoxin. As the main mycotoxin with high toxicity, wheat, barley, corn and their products are susceptible to contamination of DON. Due to the stability of this mycotoxin, traditional methods for DON reduction often require a strong oxidant, high temperature and high pressure with more energy consumption. Therefore, exploring green, efficient and environmentally friendly ways to degrade or reduce DON is a meaningful and challenging issue. Herein, a dendritic-like α-Fe2O3 was successfully prepared using a facile hydrothermal synthesis method at 160 °C, which was systematically characterized by X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). It was found that dendritic-like α-Fe2O3 showed superior activity for the photocatalytic degradation of DON in aqueous solution under visible light irradiation (λ > 420 nm) and 90.3% DON (initial concentration of 4.0 μg/mL) could be reduced in 2 h. Most of all, the main possible intermediate products were proposed through high performance liquid chromatography-mass spectrometry (HPLC-MS) after the photocatalytic treatment. This work not only provides a green and promising way to mitigate mycotoxin contamination but also may present useful information for future studies.

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Significantly Enhanced Aqueous Cr(VI) Removal Performance of Bi/ZnO Nanocomposites via Synergistic Effect of Adsorption and SPR-Promoted Visible Light Photoreduction

Catalysts ◽

10.3390/catal8100426 ◽

2018 ◽

Vol 8 (10) ◽

pp. 426 ◽

Cited By ~ 9

Author(s):

Xiaoya Yuan ◽

Zijuan Feng ◽

Jianjun Zhao ◽

Jiawei Niu ◽

Jiasen Liu ◽

...

Keyword(s):

Electron Microscopy ◽

Synergistic Effect ◽

Visible Light ◽

Photoelectron Spectroscopy ◽

Electrochemical Impedance ◽

Diffuse Reflectance Spectroscopy ◽

X Ray ◽

Enhanced Absorption ◽

Bismuth Nanoparticles ◽

Effective Transfer

Bismuth nanoparticles (BiNPs) and Zinc Oxide photocatalysts (BiNPs/ZnO) with different Bi loadings were successfully prepared via a facile chemical method. Their morphology and structure were thoroughly characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS), UV-Vis (Ultraviolet-Visible) diffuse reflectance spectroscopy (DRS), photoluminescence spectra (PL), and electrochemical impedance spectroscopy (EIS). The results showed that a modification of hexagonal wurtzite-phase ZnO nanoparticles with Bi is achievable with an intimate interfacial interaction within its composites. The performance of the photocatalytic Cr(VI) removal under visible light irradiation indicated that BiNPs/ZnO exhibited a superior removal performance to bare ZnO, Bi, and the counterpart sample prepared using a physical mixing method. The excellent performance of the BiNPs/ZnO photocatalysts could be ascribed to the synergistic effect between the considerable physical Cr (VI) adsorption and enhanced absorption intensity in the visible light region, due to the surface plasmon resonance (SPR) as well as the effective transfer and separation of the photogenerated charge carriers at the interface.

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Combining the Photocatalysis and Absorption Properties of Core-Shell Cu-BTC@TiO2 Microspheres: Highly Efficient Desulfurization of Thiophenic Compounds from Fuel

Materials ◽

10.3390/ma11112209 ◽

2018 ◽

Vol 11 (11) ◽

pp. 2209 ◽

Cited By ~ 11

Author(s):

Jing Liu ◽

Xiao-Min Li ◽

Jing He ◽

Lu-Ying Wang ◽

Jian-Du Lei

Keyword(s):

Electron Microscopy ◽

Photoelectron Spectroscopy ◽

Photocatalytic Oxidation ◽

Uv Light ◽

Sulfur Removal ◽

Oxidation Products ◽

Core Shell ◽

Adsorptive Desulfurization ◽

X Ray ◽

Tio2 Microspheres

A core-shell Cu-benzene-1,3,5-tricarboxylic acid (Cu-BTC)@TiO2 was successfully synthesized for photocatalysis-assisted adsorptive desulfurization to improve adsorptive desulfurization (ADS) performance. Under ultraviolet (UV) light irradiation, the TiO2 shell on the surface of Cu-BTC achieved photocatalytic oxidation of thiophenic S-compounds, and the Cu-BTC core adsorbed the oxidation products (sulfoxides and sulfones). The photocatalyst and adsorbent were combined using a distinct core-shell structure. The morphology and structure of the fabricated Cu-BTC@TiO2 microspheres were verified by scanning electron microscopy, high-resolution transmission electron microscopy, energy-dispersive x-ray spectroscopy, X-ray powder diffraction, nitrogen adsorption-desorption and X-ray photoelectron spectroscopy analyses. A potential formation mechanism of Cu-BTC@TiO2 is proposed based on complementary experiments. The sulfur removal efficiency of the microspheres was evaluated by selective adsorption of benzothiophene (BT) and dibenzothiophene (DBT) from a model fuel with a sulfur concentration of 1000 ppmw. Within a reaction time of 20 min, the BT and DBT conversion reached 86% and 95%, respectively, and achieved ADS capacities of 63.76 and 59.39 mg/g, respectively. The BT conversion and DBT conversion obtained using Cu-BTC@TiO2 was 6.5 and 4.6 times higher, respectively, than that obtained using Cu-BTC. A desulfurization mechanism was proposed, the interaction between thiophenic sulfur compounds and Cu-BTC@TiO2 microspheres was discussed, and the kinetic behavior was analyzed.

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Synthesis of Nanophase Noble Metal Systems Utilizing Porous Silicon

MRS Proceedings ◽

10.1557/proc-457-161 ◽

1996 ◽

Vol 457 ◽

Cited By ~ 5

Author(s):

I. Coulthard ◽

T. K. Sham

Keyword(s):

Electron Microscopy ◽

Scanning Electron Microscopy ◽

Porous Silicon ◽

Noble Metal ◽

Photoelectron Spectroscopy ◽

Room Temperature ◽

Visible Range ◽

X Ray ◽

Metallic Salt ◽

Scanning Electron

ABSTRACTApart from its well known ability to luminesce very intensely at room temperature in the visible range, porous silicon is also an effective reducing agent. We report the formation of several noble metal (Pd, Ag, Au, Pt) nanostructures by reductive dispersion of metal ions from aqueous solutions onto the surface of porous silicon. The nanophase systems produced by reductive deposition vary with the element deposited and the metallic salt utilized in the process. The resulting nanophase systems were studied using a variety of techniques including: scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and spectroscopie methods using synchrotron radiation.

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Antiphotocorrosive photocatalysts containing CdS nanoparticles and exfoliated TiO2 nanosheets

Journal of Materials Research ◽

10.1557/jmr.2010.0007 ◽

2010 ◽

Vol 25 (1) ◽

pp. 182-188 ◽

Cited By ~ 32

Author(s):

Xiaoxia Yan ◽

Gang Liu ◽

Lianzhou Wang ◽

Yong Wang ◽

Xianfang Zhu ◽

...

Keyword(s):

Electron Microscopy ◽

Visible Light ◽

Photoelectron Spectroscopy ◽

Self Assembly ◽

Inductively Coupled Plasma ◽

Atomic Emission ◽

Cds Nanoparticles ◽

Visible Absorption ◽

X Ray ◽

Tio2 Nanosheets

Aimed at designing an efficient visible light active photocatalyst and suppressing the self-corrosion tendency of CdS nanoparticles, a novel composite consisting of CdS nanoparticles and exfoliated two-dimensional (2D) TiO2 nanosheets was successfully fabricated using a simple self-assembly process. The prepared samples were characterized using various techniques including x-ray diffraction, ultraviolet–visible absorption spectroscopy, x-ray photoelectron spectroscopy, scanning electron microscopy, and transmission electron microscopy. It was found that the exfoliated 2D nanosheets played an important role as an ultrathin coating to suppress the photocorrosion of CdS nanoparticles, evidenced by inductively coupled plasma-atomic emission spectrometer analysis. The resultant CdS/TiO2 composites exhibited enhanced photocatalytic activity in the oxidation of Rhodamine B in water under visible light irradiation (λ > 420 nm).

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Hydrothermal Synthesis and Photocatalytic Properties of Flower-Like CdS Nanostructures

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.335-336.460 ◽

2011 ◽

Vol 335-336 ◽

pp. 460-463 ◽

Cited By ~ 2

Author(s):

Hong Mei Wang ◽

Da Peng Zhou ◽

Yuan Lian ◽

Ming Pang ◽

Dan Liu

Keyword(s):

Electron Microscopy ◽

Photocatalytic Activity ◽

Photoelectron Spectroscopy ◽

Uv Light ◽

Sulfur Source ◽

X Ray Diffraction ◽

Facile Hydrothermal Method ◽

X Ray ◽

Transmission Electron ◽

Cds Nanostructures

Hexagonal flower-like CdS nanostructures were successfully synthesized through a facile hydrothermal method with thiourea as sulfur source. By combining the results of X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), field-emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), the structural and morphological characterizations of the products were performed. The photocatalytic activity of CdS nanostructures had been tested by degradation of Rhodamine B (RB) under UV light compared to commercial CdS powders, which indicated that the as-syntherized CdS nanostructures exhibited enhanced photocatalytic activity for degradation of RB. The possible growth mechanism of CdS nanostructures was proposed in the end.

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Synthesis and Characterization of Heterostructure Pd/Bi2WO6 Nanocomposites with Enhanced Properties of Visible-Light-Driven Photocatalyst

10.21203/rs.3.rs-512226/v1 ◽

2021 ◽

Author(s):

Anukorn Phuruangrat ◽

Jarupat Teppetcharat ◽

Panudda Patiphatpanya ◽

Phattranit Dumrongrojthanath ◽

Somchai Thongtem ◽

...

Keyword(s):

Electron Microscopy ◽

Visible Light ◽

Photoelectron Spectroscopy ◽

Pd Nanoparticles ◽

Cubic Phase ◽

Xenon Lamp ◽

Visible Absorption ◽

X Ray ◽

Visible Light Driven ◽

20 Nm

Abstract Heterostructure Pd/Bi2WO6 nanocomposites were successful synthesized in ethylene glycol by microwave-assisted deposition method at 300 W for 10 min. Effect of the loaded Pd on phase, composition, morphology and visible-light-driven photocatalytic properties of Bi2WO6 was investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fast-Fourier-Transform (FFT) diffraction, UV-visible absorption and X-ray photoelectron spectroscopy (XPS). In this research, good distribution of cubic phase of spherical Pd nanoparticles with particle size of 15–20 nm supported on orthorhombic Bi2WO6 thin nanoplates. The 10% Pd/Bi2WO6 nanocomposites reveal major metallic Pd0 species containing in Bi2WO6 sample. Microwave can be used to synthesize metallic Pd nanoparticles supporting on top of Bi2WO6 nanoplates. Photocatalytic activities of Bi2WO6 loaded with different weight contents of Pd were monitored through photodegradation of cationic rhodamine B (RhB) dye under visible light irradiation of a xenon lamp. The 10% Pd/Bi2WO6 nanocomposites have the highest photocatalytic activity because Pd nanoparticles as electron acceptors promote interfacial charge-transfer through Pd/Bi2WO6 heterojunction.

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