Convenient preparation of CdS nanostructures as a highly efficient photocatalyst under blue LED and solar light irradiation (original) (raw)
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Synthesis of CdS nanoparticles for photocatalytic application of methyleneblue degradation
AIP Conference Proceedings, 2014
CdS nanoparticles were prepared by the reaction of cadmium acetate with thiourea in the presence and absence of methylene blue dye (MB). The nanoparticles were characterized by, XRD, FT-IR, UV-Vis. XRD study shows the presence of hexagonal phase for the nanoparticles whereas in case of the bulk samples only the hexagonal phase is observed. Fourier transform infrared spectroscopy (FT-IR) showed a strong interaction of methyl groups with CdS nanoparticles. The degradation of methylene blue was analysed using UV-Vis absorbance spectrum. Thus the results authenticate that methylene blue dye influences the structural and optical properties of the CdS nanoparticles.
Room temperature synthesis of CdS nanoflakes for photocatalytic properties
Journal of Materials Science: Materials in Electronics, 2014
Herein, we report, preparation of cadmium sulphide (CdS) nanoflakes at room temperature by simple arrested precipitation method. The synthesized CdS nanoflakes were characterized by various techniques such as X-ray diffraction, scanning electron microscopy, energy dispersive spectroscopy, Fourier transform-infrared spectroscopy, and UV-Visible spectrophotometer. Nanoflakes of CdS were found to be a mixed-phases composed of cubic and hexagonal with average crystallite size of 20 nm. Surface morphology of CdS seems to be nanoflakes. The absorption spectrum was slightly shifted to blue region as compared to the bulk, this indicates that synthesized material is smaller in size. The band gap energy was found to be 2.48 eV. The photocatalytic results reveals that CdS nanoflakes exhibits excellent photocatalytic performance for methyl orange (20 ppm) degradation, under sunlight and UV within 120 min (83 and 95 % respectively).
International Journal of Electrochemical Science
We report the influence of capping agents on the structural, photoelectrochemical and photocatalytic degradation of methylene blue (MB) dyes of monodispersed oleylamine (OLM) and octadecylamine (ODA) capped cadmium sulfide (CdS) quantum dots (QDs). Powder X-ray diffraction (pXRD) patterns of the as-prepared CdS QDs confirmed that QDs possess a hexagonal crystalline phase irrespective of the capping agents. TEM micrographs showed monodispersed spherically shaped CdS QDs with particle sizes of 3.16-5.68 and 4.71-5.61 nm for OLM-CdS and ODA-CdS QDs, respectively. The estimated band gap energy from Tauc plots were found to be 2.00 and 2.04 eV for OLM-CdS and ODA-CdS QDs, indicating that the as-prepared CdS QDs are quantum confined due to their small sizes and absorption band edges that are blue-shifted. Electrochemical band gaps were found to be 0.25 mV/s for OLM-CdS and 0.99 mV/s for ODA-CdS. The prepared CdS QDs were then used as photocatalysts for the degradation of MB dye and yielded a degradation efficiency of 65% for OLM-CdS and 76% for ODA-CdS QDs. This confirmed that the capping agent influences the photocatalytic degradation efficiency of the as-prepared CdS quantum dots.
CdS nanoparticles (NPs) were synthesized using co-precipitation method. X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) were used to confirm the structures and morphologies of CdS NPs. X-ray diffraction data confirmed the crystal structure of the CdS NPs. Raman spectrum exhibited the Raman modes of LO and 2LO of CdS at 290 and 595 cm -1 respectively. The evaluated band gap was 3.15 eV, this value was shifted compared with the bulk value and this could be a significance of a size quantization effect in the sample. The CdS nanoparticles showed higher photocatalytic activity for the discoloration of methyl orange (MO) under UV light irradiation for 90 min. The highest photocatalytic activity was obtained with the sample containing 0.3 wt % CdS nanoparticles, in which more than 98 % of the MO was discolored within 90 min.
CdS nanostructures of different shapes such as, nanoparticles (NPs), nanosheets (NS) and nanorods (NRs) have been synthesized by one step chemical solvothermal method. The synthesized samples were characterized by X-ray diffractometer (XRD), transmission electron microscopy (TEM), photoluminescence (PL) spectroscopy, UV–visible (UV-VIS) spectroscopy, Raman spectroscopy (RS) and vibrating sample magnetometer (VSM) techniques. The effect of shape on optical and magnetic properties of CdS nanostructures was studied. The optical band gap and emission spectra are found to be shape dependent. CdS NRs were found to have high saturation (Ms) magnetization than that of CdS NPs and NS. The role of shape on photocatalytic performance of CdS NPs, NS and NRs was investigated by monitoring the photodegradation of methylene blue (MB) dye under the UV irradiation of wavelength 365 nm. The lower recombination rate of electron-hole pairs and larger surface area as reactive facets for adsorption of MB dye molecules in CdS NS are mainly lead to the better photocatalytic performance of CdS NS compared to NPs and NRs.
Enhancing Photocatalytic Degradation of Methyl Blue Using PVP-Capped and Uncapped CdSe Nanoparticles
Quantum connnement of semiconductor nanoparticles is a potential feature which can be interesting for photocatalysis, and cadmium selenide is one simple type of quantum dot to use in the following photocatalytic degradation of organic dyes. CdSe nanoparticles capped with polyvinylpyrrolidone (PVP) in various concentration ratios were synthesized by the chemical reduction method and characterized. e transmission electron microscopy (TEM) analysis of the samples showed that 50% PVP-capped CdSe nanoparticles were uniformly distributed in size with an average of 2.7 nm and shape which was spherical-like. e photocatalytic degradation of methyl blue (MB) in water showed eeciencies of 31% and 48% when using uncapped and 50% PVP-capped CdSe nanoparticles as photocatalysts, respectively. e eeciency of PVP-capped CdSe nanoparticles indicated that a complete green process can be utilized for photocatalytic treatment of water and waste water.
International Journal of Nanotechnology, 2021
The structural regulation of nanoparticles is a challenging task without any structure determining agents such as templates, surfactants, etc. In the present study, the structure of cadmium sulphide nanoparticles (CdS NPs) has been effortlessly changed from hexagonal to face centred cubic structure under solvothermal conditions by facile volume ratio adjustment of the solvents (water and ethanol). The various CdS NPs prepared have been investigated using different characterisation techniques and their structure, size and morphology vary with respect to the solvent composition. Furthermore, the photocatalytic performance of CdS NPs has been investigated using Methylene Blue (MB) as model organic pollutant. It has been observed that the photocatalytic degradation efficiency of MB is significantly influenced by the structure of CdS NPs.
Synthesis, Characterisation and Photocatalytic Activity of Cadmium Sulphide Nanoparticles
Chemical Science Transactions, 2016
Cadmium sulphide (CdS) nanoparticles were synthesized using thiourea as a source for sulphide ion in the presence of disodium succinate. The prepared nanoparticles were characterized by IR spectroscopy, x-ray diffraction and scanning electron microscopy. The photocatalytic activity of CdS was tested for degradation of methylene blue and rhodamine B. CdS catalyst shows high activity for the photocatalytic degradation of methylene blue dye.
Journal of Physics and Chemistry of Solids, 2018
A simple, facile and organic-free hydrothermal method was utilized to synthesize cadmium sulfide (CdS) superstructures. The cadmium chloride and thiourea used as a Cd 2þ and S 2À ion sources for the growth of CdS superstructures. The reaction was carried out at different time and temperatures. The X-ray diffraction studies confirmed that the obtained products were highly crystalline with hexagonal phase. Scanning and transmission electron microscopy images reveal a monodisperse dendrite-like CdS superstructure. It consisted of a central long trunk with secondary branches, lying parallel to each other and making a certain angle with the central trunk, and small ternary branches grew out of the secondary branches. The selected area electron diffraction altogether with high-resolution electron microscopy patterns depicted that the leaves of dendrite were single crystalline in nature and preferentially grown along (111) direction. The UV-vis absorbance and photoluminescence study illustrated that the hierarchically grown CdS superstructures revealed the good quality of optical properties. A probable growth mechanism for the formation of CdS dendritic superstructures was also discussed and demonstrated by experimental results. The photocatalytic activity of CdS superstructures was studied with the photodegradation of methylene blue (MB) in an aqueous solution, under the visible light irradiation. The results showed that the degradation ratio of MB could reach 94.93% in 220 min. Based on the results, the possible mechanism of the photocatalytic reaction of MB with CdS dendrites is useful for visible light photocatalytic applications.
Journal of Advanced Scientific Research, 2022
The present analysis explores the photocatalytic activity of Ti-doped CdSe and undoped CdSe nanoparticles towards Methylene Blue (MB) dye degradation under solar light irradiation. The as prepared Ti-CdSe and mere CdSe nanoparticles were characterized using XRD, UV, FTIR, TGA, SEM and TEM analysis. TEM micrographs confirm the synthesized samples are in nanometer regime. The insertion of Titania onto CdSe lattice was confirmed by XRD and SEM-EDAX analysis. The absorption spectrum of Ti doped CdSe nanoparticles showed blue shift (lower wavelength) than mere CdSe. Ti-CdSe nanoparticles have greater thermal stability than mere CdSe nanoparticles. The photocatalytic activity of the Ti-CdSe nanoparticles photocatalyst was determined by degrading a MB dye under solar light irradiation. Ti-CdSe nanoparticles maintain high photocatalytic activity under solar light irradiation in comparison to mere CdSe nanoparticles. Low electron-hole pair recombination with increased efficiency was observed...