The structural and optical constants of Ag2S semiconductor nanostructure in the Far-Infrared

Zamiri, Reza; Ahangar, Hossein Abbastabar; Zakaria, Azmi; Zamiri, Golnoosh; Shabani, Mehdi; Singh, Budhendra; Ferreira, J.M.F.

doi:10.1186/s13065-015-0099-y

Cited by 92 publications

(38 citation statements)

References 22 publications

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“…3b). The values for the band gap energies obtained for both BiVO 4 and Ag 2 S are in agreement with previously reported values for the semiconductors 48,49 . electrochemical and photoelectrochemical analysis.…”

Section: Resultssupporting

confidence: 91%

Towards visible light driven photoelectrocatalysis for water treatment: Application of a FTO/BiVO4/Ag2S heterojunction anode for the removal of emerging pharmaceutical pollutants

Orimolade

Arotiba

2020

Sci Rep

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Pharmaceuticals have been classified as emerging water pollutants which are recalcitrant in nature. In the quest to find a suitable technique in removing them from contaminated water, photoelectrocatalytic oxidation method has attracted much attention in recent years. this report examined the feasibility of degrading ciprofloxacin and sulfamethoxazole through photoelectrocatalytic oxidation using fto-BiVo 4 /Ag 2 S with p-n heterojunction as anode. BiVo 4 /Ag 2 S was prepared through electrodeposition and successive ionic layer adsorption/reaction on fto glass. Structural and morphological studies using XRD, SEM, EDS and diffusive reflectance UV-Vis confirmed the successful construction of p-n heterojunction of BiVo 4 /Ag 2 S. electrochemical techniques were used to investigate enhanced charge separation in the binary electrode. the fto-BiVo 4 /Ag 2 S electrode exhibited the highest photocurrent response (1.194 mA/cm −2 ) and longest electron lifetime (0.40 ms) than both pristine BiVo 4 and Ag 2 S electrodes which confirmed the reduction in recombination of charge carriers in the electrode. Upon application of the prepared FTO-BiVO 4 /Ag 2 S in photoelectrocatalytic removal of ciprofloxacin and sulfamethoxazole, percentage removal of 80% and 86% were achieved respectively with a low bias potential of 1.2 V (vs Ag/AgCl) within 120 min. The electrode possesses good stability and reusability. the results obtained revealed BiVo 4 /Ag 2 S as a suitable photoanode for removing recalcitrant pharmaceutical molecules in water. open Scientific RepoRtS | (2020) 10:5348 | https://doi.org/10.1038/s41598-020-62425-w www.nature.com/scientificreports www.nature.com/scientificreports/ Scientific RepoRtS | (2020) 10:5348 | https://doi.org/10.1038/s41598-020-62425-wwww.nature.com/scientificreports www.nature.com/scientificreports/ the BiOI electrode. The electrode was subsequently placed in a furnace at 420 °C for 1 h. Finally, excess V 2 O 5 was washed off from the electrode by soaking it in 1.0 M NaOH solution for 40 min. The resulting BiVO 4 /FTO electrode was thoroughly washed with deionized water and dried at room temperature. In order to obtain BiVO 4 / Ag 2 S electrode, the prepared FTO/BiVO 4 was dipped in a 0.3 M AgNO 3 solution for 10 s and followed by immersion in 0.3 M Na 2 S for 10 s. The cycle was repeated ten times and the obtained electrode was rinsed with deionized water and air dried at room temperature for 24 h. Scientific RepoRtS |(2020) 10:5348 | https://doi.org/10.1038/s41598-020-62425-w www.nature.com/scientificreports www.nature.com/scientificreports/ conclusion A photoanode of BiVO 4 /Ag 2 S with p-n heterojunction was successful prepared through electrodeposition and successive ionic layer adsorption/reaction method on FTO glass. The construction of p-n heterojunction reduced the common problem of rapid recombination of photogenerated electron-hole pairs. This was confirmed through the photocurrent response of BiVO 4 /Ag 2 S (1.194 mA/cm −2 ) which was higher than both pristine BiVO 4 (0.802 mA/cm −2 ) and...

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Section: Resultssupporting

confidence: 91%

Towards visible light driven photoelectrocatalysis for water treatment: Application of a FTO/BiVO4/Ag2S heterojunction anode for the removal of emerging pharmaceutical pollutants

Orimolade

Arotiba

2020

Sci Rep

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“…The three samples (prepared at 140-180 • C) produced the Tauc plots for a direct semiconductor, which included well-defined straight regions from which the band gap values (E g ) were estimated to be 2.11-2.14 eV. However, the NPs synthesized at 130 • C exhibited an absorption tail at >850 nm, which corresponded to the remaining intermediate Ag 2 S with a band gap of 1.1 eV [33]. The elemental composition of NPs supported similar assumptions ( Table 1) that are discussed above, indicating that the less reactive indium species needs a temperature higher than 140 • C to be fully incorporated in nanoparticles.…”

Section: Effect Of Temperature On the Generation Of Agins 2 Qds By Dmmentioning

confidence: 99%

Core Nanoparticle Engineering for Narrower and More Intense Band-Edge Emission from AgInS2/GaSx Core/Shell Quantum Dots

et al. 2019

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Highly luminescent silver indium sulfide (AgInS 2 ) nanoparticles were synthesized by dropwise injection of a sulfur precursor solution into a cationic metal precursor solution. The two-step reaction including the formation of silver sulfide (Ag 2 S) nanoparticles as an intermediate and their conversion to AgInS 2 nanoparticles, occurred during the dropwise injection. The crystal structure of the AgInS 2 nanoparticles differed according to the temperature of the metal precursor solution. Specifically, the tetragonal crystal phase was obtained at 140 • C, and the orthorhombic crystal phase was obtained at 180 • C. Furthermore, when the AgInS 2 nanoparticles were coated with a gallium sulfide (GaS x ) shell, the nanoparticles with both crystal phases emitted a spectrally narrow luminescence, which originated from the band-edge transition of AgInS 2 . Tetragonal AgInS 2 exhibited narrower band-edge emission (full width at half maximum, FWHM = 32.2 nm) and higher photoluminescence (PL) quantum yield (QY) (49.2%) than those of the orthorhombic AgInS 2 nanoparticles (FWHM = 37.8 nm, QY = 33.3%). Additional surface passivation by alkylphosphine resulted in higher PL QY (72.3%) with a narrow spectral shape.in the visible region as well as large optical absorption coefficients, which are characteristic for direct semiconductors [9][10][11][12][13]. Among these QDs, silver indium sulfide (AgInS 2 ) nanoparticles (NPs) with a band gap energy of 1.87 eV have attracted increasing attention [14,15]. A universal challenge during the synthesis of AgInS 2 NPs is to balance the reactivity of two cationic precursors against one anionic precursor [10,16]. In the past, the thermal decomposition of a single molecular precursor was used to avoid the reactivity problem, which resulted in a high (~50%) PL QY for AgInS 2 -ZnS NPs [17][18][19]. The limitations of this method are the necessity of designing a molecular precursor for each composition and the difficulty of controlling the particle size and shape due to the complexity of the decomposition process [20]. Alternatively, the reactions of the cation mixture with sulfur-containing species at higher temperatures are common. A typical example uses silver nitrate (AgNO 3 ), indium acetate (In(OAc) 3 ), and 1-dodecanethiol (DDT) dissolved in 1-octadecene (ODE), which were heated until DDT reacted with metal cations to generate AgInS 2 NPs [21]. Although the "heating up" approach achieved better PL QY, it was still difficult to regulate the particle size because the growth process mainly occurred by Ostwald ripening [22,23]. At the same time, the method of particle size control by the rapid injection of precursors into a hot solvent, which has been commonly used for binary semiconductor QDs, was also adopted for the AgInS 2 NPs synthesis and achieved good size distribution with a PL QY as high as 59% [24][25][26]. Although the control over particle size and composition was achieved, none of these attempts generated a narrow band-edge emission corresponding to common II-VI semiconductor QD...

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“…Figure S3 shows the infrared (IR) spectrums recorded during CNT-ME aptasensor fabrication. The spectrum (a) presents the Ag-Cysteamine, and the peak at 500 cm −1 , corresponding to Ag-S stretching vibration, confirming the chemical attachment of cysteamine on the electrode surface [41]. The peaks at 800, 3360, and 1500 cm −1 corresponded to the C-H stretching vibration, the N-H, and NH 2 stretching vibration.…”

Section: Electrochemical Characterizationmentioning

confidence: 73%

“…for instance, the difference in the number of aptamers immobilized on WE between one aptasensor and another may decrease the sensitivity. However, by subtracting the current generated from the blank sample, in this way, only the current generated because of the analyte will be measured, no matter the amount of the aptamers immobilized on the WE [ 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 ]. Hence, we increase the reproducibility of the aptasensors.…”

Section: Resultsmentioning

confidence: 99%

Flexible Screen Printed Aptasensor for Rapid Detection of Furaneol: A Comparison of CNTs and AgNPs Effect on Aptasensor Performance

et al. 2020

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Furaneol is a widely used flavoring agent, which can be naturally found in different products, such as strawberries or thermally processed foods. This is why it is extremely important to detect furaneol in the food industry using ultra-sensitive, stable, and selective sensors. In this context, electrochemical biosensors are particularly attractive as they provide a cheap and reliable alternative measurement device. Carbon nanotubes (CNTs) and silver nanoparticles (AgNPs) have been extensively investigated as suitable materials to effectively increase the sensitivity of the biosensors. However, a comparison of the performance of biosensors employing CNTs and AgNPs is still missing. Herein, the effect of CNTs and AgNPs on the biosensor performance has been thoughtfully analyzed. Therefore, disposable flexible and screen printed electrochemical aptasensor modified with CNTs (CNT-ME), or AgNPs (AgNP-ME) have been developed. Under optimized conditions, CNT-MEs showed better performance compared to AgNP-ME, yielding a linear range of detection over a dynamic concentration range of 1 fM–35 μM and 2 pM–200 nM, respectively, as well as high selectivity towards furaneol. Finally, our aptasensor was tested in a real sample (strawberry) and validated with high-performance liquid chromatography (HPLC), showing that it could find an application in the food industry.

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The structural and optical constants of Ag2S semiconductor nanostructure in the Far-Infrared

Cited by 92 publications

References 22 publications

Towards visible light driven photoelectrocatalysis for water treatment: Application of a FTO/BiVO4/Ag2S heterojunction anode for the removal of emerging pharmaceutical pollutants

Towards visible light driven photoelectrocatalysis for water treatment: Application of a FTO/BiVO4/Ag2S heterojunction anode for the removal of emerging pharmaceutical pollutants

Core Nanoparticle Engineering for Narrower and More Intense Band-Edge Emission from AgInS2/GaSx Core/Shell Quantum Dots

Flexible Screen Printed Aptasensor for Rapid Detection of Furaneol: A Comparison of CNTs and AgNPs Effect on Aptasensor Performance

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