PROFICIENT PHOTOCATALYTIC DEGRADATION OF METHYLENE BLUE DYE USING Ti-DOPED CdSe NANOPARTICLES UNDER SOLAR LIGHT IRRADIATION (original) (raw)
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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.
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.
Photocatalytic decolourization of brilliant green and methylene blue by TiO2/CdS nanorods
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The present work narrates the photocatalytic behaviour of TiO 2 /CdS nanocomposites for the degradation of the organic dyes brilliant green and methylene blue under solar light irradiation. For this process, TiO 2 loaded with different concentrations of CdS was prepared through a sol-gel approach and the prepared products were studied for their structural, optical and morphological characteristics. The degradation details of the studied composites reveal that TiO 2 loaded with an optimum level of CdS is known to have outstanding catalytic activity due to its higher BET surface area, rod-like morphology and low charge transfer resistance.
Separation and Purification Technology, 2013
Cadmium sulphide (CdS) nanostructures were synthesized via a simple chemical precipitation method by using Mercaptoethylamine hydrochloride (MEA) as a capping agent. Fine tuning of the nanosized CdS material was carried out by controlling the amount of the capping agent. The synthesized CdS nanostructures were characterized by UV-Vis spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), and UV-Vis diffuse reflectance spectroscopy (DRS). Optical absorption spectroscopy was mainly used to measure the band gap and size of the CdS nanostructures. The photocatalytic activities of the synthesized samples were investigated for degradation of methylene blue (MB) under blue LED (3 W) and solar light irradiation.
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.
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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.
Beilstein journal of nanotechnology, 2017
CdSe nanorods (NRs) with an average length of ≈120 nm were prepared by a solvothermal process and associated to TiO2 nanoparticles (Aeroxide® P25) by annealing at 300 °C for 1 h. The content of CdSe NRs in CdSe/TiO2 composites was varied from 0.5 to 5 wt %. The CdSe/TiO2 heterostructured materials were characterized by XRD, TEM, SEM, XPS, UV-visible spectroscopy and Raman spectroscopy. TEM images and XRD patterns show that CdSe NRs with wurtzite structure are associated to TiO2 particles. The UV-visible spectra demonstrate that the narrow bandgap of CdSe NRs serves to increase the photoresponse of CdSe/TiO2 composites until ≈725 nm. The CdSe (2 wt %)/TiO2 composite exhibits the highest photocatalytic activity for the degradation of rhodamine B in aqueous solution under simulated sunlight or visible light irradiation. The enhancement in photocatalytic activity likely originates from CdSe sensitization of TiO2 and the heterojunction between these materials which facilitates electron t...
Journal of Nanotechnology
Reusable photocatalytic polyacrylonitrile membrane-supported cadmium sulphide/titanium dioxide hybrid nanoparticles (CdS/TiO2-PAN) were prepared using a dry-wet phase inversion technique. Scanning electron microscopy (SEM) analysis revealed that the photocatalytic membranes had a porous sublayer, a compact top layer, and that, some of the nanoparticles were not encapsulated by the membranes. The average crystallite sizes of the CdS, TiO2, and CdS/TiO2 hybrid nanoparticles were 3.41 nm, 10.47 nm, and 12.17 nm, respectively. The combination of CdS and TiO2 nanoparticles led to a red shift (band gap; ca. 2.6 eV) of the absorption band and extended the optical absorption spectrum into the visible region relative to TiO2. The photocatalytic activity of CdS/TiO2-PAN membranes was explored in the degradation of methylene blue dye under visible light irradiation, and the results revealed that the best photocatalytic performance was achieved by 0.1 g CdS/TiO2-PAN photocatalytic membrane with...
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.
CdS-1 (nanosphers) and CdS-2 (nanocapsule), were synthesized via green synthetic route without using any toxic surfactants by thermolysis of bis(4-benzhydrylpiperazine-1-carbodithioate-κ 2 S, Sʹ)cadmium(II) (1) and bis (4benzylpipera-zine-1-carbodithioate-κ 2 S, Sʹ)cadmium(II) (2), respectively in the presence of ethylenediamine as a solvent. The nanoparticles were characterized by TEM, XRD, SEM, FT-IR UV-Visible and Fluorescence spectroscopy. The TEM results showed the formation of nanospheres (CdS-1) and nanocapsules (CdS-2) from complexes 1 and 2, respectively. Both CdS nanoparticles (NPs) have hexagonal crystal phase and a band gap value in the visible region as confirmed by the XRD and UV-Visible spectra, respectively. The photoluminescence (PL) data revealed that CdS-2 has longer recombination time of photo-injected electron hole pairs than CdS-1. The similar FT-IR spectra for both CdS NPs, and different HOMO-LUMO gap values for complexes {4.8187 eV (1) and CdS-2 4.7504 eV (2)} as predicted by DFT calculations suggest that stability of complexes play a key role in controlling morphology. Furthermore, the visible light driven photocatalytic degradation of Congo red dye was observed higher for nanocapsules than nanospheres due to a longer recombination time of photo-injected electron hole pairs.