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Facile synthesis of La-doped CdS nanoparticles by microwave assisted co-precipitation technique for optoelectronic application
摘要： Low-cost microwave assisted technique has been applied to produce La-doped CdS nanoparticles and their structural, morphological, optical, Raman, dielectric and electrical studies were carried out. Broad XRD peaks revealed the growth of low-dimension La-doped CdS nanoparticles with wurtzite structure. Spherical shape morphology of synthesized nanostructures was confirmed by SEM analysis. SEM mapping and EDAX analysis showed the elemental composition and successful incorporation of La in CdS matrix. Diffused reflectance spectroscopy was used to determine the energy gaps and it was observed to be reduced from 2.47 to 2.3 eV upon La doping. Vibrational studies on La:CdS nanoparticles displayed longitudinal optical modes. PL studies exhibited improved luminescence for the band to band transition of the CdS nanoparticles. The ε’ values are enhanced in general; though it displayed reduced ε’ values at some concentration owing to reduction of polarization. Enhancement in AC conductivity was observed with increasing La concentration and the studies on the involved conduction mechanism revealed that the hopping motion in prepared nanostructures is translation motion with a quick hopping and the behavior is that of ionic conduction.
关键词： FT-Raman spectroscopy,optical properties,dielectric and electrical properties,X-ray diffraction,SEM/EDX,La:CdS
更新于2025-09-23 15:21:01
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One Dimensional CdS Nanotube vs CdS Bulk Structure for Photocatalytic Water Splitting: Role of Dimensionality
摘要： Using the state-of-the-art density functional theoretical calculations, we have modelled a facetted CdS nanotube (NT) catalyst for photocatalytic water splitting. The overall photocatalytic activity of the CdS photocatalyst has been predicted based on the electronic structures, band edge alignment, and overpotential study. For comparisons, we have also investigated the water spilitting process over the CdS bulk structure. The band edge alignment along with oxygen evolution reaction/hydrogen evolution reaction (OER/HER) mechanism studies help us to find out the effective overpotential for the overall water splitting on these surfaces. Our study shows that CdS NT has highly stabilized valence band edge compared to that in the CdS bulk due to strong p-d mixing. Such highly stabilized valence band edge is important for the hole-transfer process and reduces the risk of electron-hole recombination. Such nanotube requires less overpotential for water oxidation reaction than the periodic CdS. All these suggest that the efficiency of water oxidation/reduction process further improves in CdS as we reduce its dimensionality. More importantly, we report here that there are two factors, which makes CdS nanotube as a better photocatalyst material compared to its bulk counterpart. Furthermore, the stabilized valence band edge is good for their photostability too as bulk CdS suffers from photostability.
关键词： photocatalysis,HER,CdS nanotube,OER,electron-hole recombination
更新于2025-09-23 15:21:01
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In situ synthesis of a cadmium sulfide/reduced graphene oxide/bismuth Z-scheme oxyiodide system for enhanced photocatalytic performance in chlorinated paraben degradation
摘要： An efficient reduced graphene oxide (rGO)-based cadmium sulfide/reduced graphene oxide/bismuth oxyiodide (CdS/rGO/BiOI) Z-scheme system was fabricated by an in-situ growth method. Solid interactions between the rGO and nanoparticles promoted the transmission of photoinduced carriers, which separated and accumulated electrons from CdS and holes from BiOI. Moreover, the Z-scheme system enabled CdS electrons to maintain a high reduction capability and BiOI holes to maintain a high oxidation capability. Therefore, the CdS/rGO/BiOI composite exhibited better photocatalytic activity in the degradation of methyl 3,5-dichloro-4-hydroxybenzoate (MDHB) than that of pure CdS and BiOI under visible light irradiation. In particularly, the identification of active species and transformation products revealed that the accumulated photoinduced electrons promoted the reductive dechlorination of MDHB. The dechlorinated byproducts were then oxidatively split and degraded into harmless small-molecule carboxylic acids or inorganic substances by photoinduced holes. This work provided a favorable in situ growth method to design and synthesize Z-scheme photocatalysts for simultaneous chlorinated paraben dechlorination and degradation under visible light irradiation.
关键词： Dechlorination,Visible light photocatalysis,CdS/rGO/BiOI composite,Z-scheme,Chlorinated paraben
更新于2025-09-23 15:21:01
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Synthesis of hollow core-shell CdS@TiO2/Ni2P photocatalyst for enhancing hydrogen evolution and degradation of MB
摘要： During the photocatalytic production of hydrogen gas, close interface with a catalyst is very important. We designed a noble-metal-free photocatalytic system that is spatially separated to produce hydrogen by high frequency visible light. We used a new type of a catalyst consisting of hollow core-shell CdS@TiO2/Ni2P structures prepared using sacrificial template method. Photocatalytic decomposition of water was tested using this catalyst. Hydrogen production yield using 420 nm light was 14.80 mmol/g after 2.5 h and using Xe lamp with AM1.5G filter was 34.78 mmol/g after 2.5 h. Hollow core shell CdS@TiO2/Ni2P particles were more stable than hollow core shell CdS@TiO2/Pt structures because TiO2 protected CdS from photo-corrosion. Combination of CdS and Ni2P increased absorption range of TiO2 at 720 nm. Holes and electrons produced during the photo-reaction can migrate to the CdS on the inside and to the Ni2P on the outside of the TiO2 protective coating. Such design exposes more surface, thus, increases hydrogen production.
关键词： template,hydrogen production,CdS@TiO2/Ni2P,hollow core-shell
更新于2025-09-23 15:21:01
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Carbon quantum dots assisted strategy to synthesize Co@NC for boosting photocatalytic hydrogen evolution performance of CdS
摘要： Photocatalytic water splitting accompanied by the hydrogen production as a prospective method has been placed on solving the double issues of the energy crisis and environment pollution. Therefore, the development of stable and efficient hydrogen evolving photocatalysts is pretty important and urgent. Herein, the Co@NC (Co nanoparticles wrapped by nitrogen doped carbon layers) derived from the mixture of carbon quantum dots (CQDs) and Co2+ as the cocatalyst is loaded on the surfaces of the CdS nanorods (NRs) for photocatalytic hydrogen production. The results show a hydrogen evolution activity of 21.8 mmol g-1 h-1 for CdS with 3 wt % loading amount of Co@NC (CdS-3) and 29.8 times higher than that of CdS alone. In addition, an apparent quantum efficiency (AQE) of 41.8 % at 420 nm over the CdS-3 is obtained. The enhanced photocatalytic performance of the hybrid nanostructure is largely ascribed to the effective electron transfer (ET) between the CdS NRs and Co@NC, which is confirmed by the electrochemical experiments and photoluminescence (PL) spectra. In all, this work supplies a novel strategy to synthesize universal photocatalytic cocatalyst.
关键词： Carbon quantum dots,1D CdS,Synergistic effect,Hydrogen evolution reaction,Photocatalysis
更新于2025-09-23 15:19:57
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Q-switched fiber laser based on CdS quantum dots as a saturable absorber
摘要： In this work, a Q-switched fiber laser is demonstrated using quantum dots (QDs) cadmium sulfide (CdS) as a saturable absorber (SA) in an erbium-doped fiber laser (EDFL) system. The QD CdS is synthesized via the microwave hydrothermal assisted method and embedded into polyvinyl alcohol (PVA). The QD CdS/PVA matrix film is sandwiched in between two fiber ferrules by a fiber adapter. The generation of Q-switched fiber laser having a repetition rate, a pulse width, and a peak-to-peak pulse duration of 75.19 kHz, 1.27 μs, and 13.32 μs, respectively. The maximum output power of 3.82 mW and maximum pulse energy of 50.8 nJ are obtained at the maximum pump power of 145.9 mW. The proposed design may add to the alternative material of Q-switched fiber laser generation, which gives a high stability output performance by using quantum dots material as a saturable absorber.
关键词： CdS Quantum Dots,erbium-doped fiber laser,microwave hydrothermal assisted method,saturable absorber,Q-switched fiber laser
更新于2025-09-23 15:19:57
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Investigation of thin-film p-BaSi<sub>2</sub>/n-CdS heterostructure towards semiconducting silicide based high efficiency solar cell
摘要： In this article, semiconducting Barium Silicide (BaSi2) absorber based Al/SnO2:F/CdS/BaSi2:B/Cu novel heterostructure thin-film solar cell (TFSC) has been studied in details. The solar cell has been numerically simulated and intensely analyzed by Solar cell Capacitance Simulator (SCAPS). Layer thickness was varied from 100-3000 nm for p+-BaSi2 absorber, 20-200 nm for both n-CdS buffer, and n+-SnO2:F window layers to optimize the device. Hitherwards, the impurities concentration for acceptor (NA) and donor (ND) ions was optimized for each layer through ample variation. The influence of single-donor and acceptor type bulk defect densities has been investigated thoroughly in p+-BaSi2 and n-CdS materials, respectively. An efficiency >30% is achievable ideally with a 2 μm thick BaSi2 absorber without incorporating defects whereas it reduces to 26.32% with only 1.2 μm thick absorber including certain amount of defects. Cell thermal stability and alteration of cell parameters were studied under cell operating temperature from 273°K to 473°K. Finally, the effect of series (Rs) and shunt (Rsh) resistances on proposed cell has been investigated meticulously. This newly designed solar cell structure proclaims the chance of fabricating a resourceful, low cost, and highly efficient TFSC near future.
关键词： SnO2:F window,Thin-film solar cell,BaSi2 absorber,SCAPS simulation,CdS buffer,Optimization
更新于2025-09-23 15:19:57
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Screening and characterisation of CdTe/CdS quantum dot-binding peptides for material surface functionalisation
摘要： Quantum dots (QDs) are promising nanomaterials due to their unique photophysical properties. For them to be useful in biological applications, the particle surface generally needs to be conjugated to biological molecules, such as antibodies. In this study, we screened CdTe/CdS QD-binding peptides from a phage display library as linkers for simple and bio-friendly QD modification. Among five QD-binding peptide candidates, a series of truncated peptides designed from two high-affinity peptides were subjected to an array-based binding assay with QDs to assess their functional core sequences and characteristics. Linking these isolated, shortened peptides (PWSLNR and SGVYK) with an antibody-binding peptide (NKFRGKYK) created dual-functional peptides that are capable of QD surface functionalisation by antibodies. Consequently, the dual-functional peptides could mediate anti-CD9 antibody functionalisation onto CdTe/CdS QD surface; CD9 protein imaging of cancer cells was also demonstrated. Our proposed peptides offer an effective vehicle for QD surface functionalisation in biological applications.
关键词： surface functionalisation,Quantum dots,bioimaging,peptides,CdTe/CdS,phage display,antibody conjugation
更新于2025-09-23 15:19:57
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Comparative studies of CdS thin films by chemical bath deposition techniques as a buffer layer for solar cell applications
摘要： Cadmium sulfide (CdS) buffer layer that decouples the absorber layer and window layer in thin-film solar cells was synthesized by two different chemical bath deposition (CBD) techniques with varying deposition parameters. X-ray diffraction (XRD) revealed that the CdS thin film crystallizes in a stable hexagonal wurtzite structure having a preferential orientation along (002) reflection plane with a crystallite size varying from 20 to 40 nm. First longitudinal optical phonon mode was identified at Raman shift of 305 cm?1. Uniform, granular, continuous, and smooth surface with an average grain sizes (< 100 nm) as well as small roughness (< 9 nm) was observed by scanning electron microscopy (SEM) and atomic force microscopy (AFM), respectively. The symmetric composition of cadmium and sulfur along with larger grains (20 nm) was observed at higher deposition temperatures and times. The optical band gap of CdS samples obtained from process one was in the range of 2.3–2.35 eV, while the band gap by the second CBD process lay in between 2.49 and 2.65 eV, showing the most stable compound of CdS. The presence of a green emission band in photoluminescence spectra (PL) demonstrated that the CdS material has better crystallinity with minimum defect density. Hall effect studies revealed the n-type conductivity of CdS thin films with a carrier concentration values in the order of 1016 cm?3. Furthermore, CdS thin films fabricated by CBD process exposed better quality that might be more suitable material as a buffer layer for thin-film solar cells.
关键词： solar cells,buffer layer,optical properties,electrical properties,chemical bath deposition,CdS thin films
更新于2025-09-23 15:19:57
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CdS core-Au/MXene-based photodetectors: Positive deep-UV photoresponse and negative UVa??Vis-NIR photoresponse
摘要： Exploring photodetectors with higher responsitivity and broader spectral response is crucial for optoelectronic applications. Inverse photoresponse is discovered from photodetectors based on cadmium sulfide modified by Au (CdS core-Au). The devices are capable of detecting photons with a broader spectrum from deep-ultraviolet to near-infrared. Under the illumination of visible light at 405 nm, negative photoresponse with higher responsivity (86 mA/W) and larger specific detectivity (1.34×1011 Jones) are observed owing to the thermal mechanism. Upon deep-ultraviolet light illumination, the photodetectors exhibit positive photoresponse. These findings provide a new approach to broad spectral photodetectors and other inventive optoelectronic devices.
关键词： broader spectrum,positive photoresponse,negative photoresponse,photodetector,CdS core-Au
更新于2025-09-23 15:19:57