Hybrid Nanocomposite Thin Films Research Articles

Preparation and Study the Properties of PVDF/PEO/WO2 Hybrid Nanocomposite Thin Films Prepared by a Spin Coating Method

In this work, using the spin coating method to create polyvinylidene fluoride (PVDF)/polyethylene oxide (PEO) thin films, the effects of nano-tungsten oxide (WO2) doping were investigated. The novelty of this research lies in its investigation of varying weight concentrations of WO2 nanoparticles (NPs) within the composite films. Comprehensive characterization techniques were employed, including structural analysis via X-ray diffraction (XRD), which revealed a clear and prominent peak in the XRD of the PVDF/PEO films, and the films' polycrystalline nature with tetragonal structures. The grain size was noted to increase with higher WO2 NPs doping. Field emission scanning electron microscopy (FE-SEM) showed hexagonal-like α-phase PVDF crystals and uniform distribution of WO2 NPs. Furthermore, Fourier-transform infrared spectroscopy (FTIR) confirmed the characteristics of PVDF/PEO and identified specific doping compounds, confirming successful incorporation. The optical transmittance spectra unveiled the films' optical band gap energy, optical transition types, and absorption characteristics, where novelty emerged as the band gap energy significantly increased from 3.0 eV to 3.64 eV with an increased WO2 NPs weight doping percentage, signifying profound electronic structure modifications and potential applications in optoelectronics and sensors.

Thermal Annealing Impact on Optical Properties of Spin-coated P3HT: CdS Thin Film

Polymers are flexible materials that can be easily processed and are formed into a thin film by several methods such as spin-coating, dip-coating, film-casting, and printing. The spin coating method has been extensively utilized in fabricating solution-prepared organic/inorganic electronic devices, this technique is positively efficient in generating thin film apart from being a flexible method to execute. In this study, poly(3-hexylthiophene) (P3HT) material is selected as polymer and cadmium sulphide (CdS) as nanoparticles to produce a hybrid nanocomposite thin film through the process spin-coating method. The P3HT and cadmium ion solution were used to fabricate a thin film onto a quartz glass substrate at a spin speed of 500 rpm for 10 seconds. This spin-coated thin film was heated at different temperatures such as 40°C, 80°C, 120°C, and 160°C for optical properties using a UV-Vis spectrophotometer. The UV-Vis absorption spectra of P3HT: CdS indicated absorption peaks in the UV region, which were ascribed to the band gap of the P3HT: CdS thin film. Our results showed that the optical properties of the P3HT: CdS be contingent on the annealing temperature. The film at room temperature yielded a band gap value of 1.98 eV, at 40°C it resulted in 1.99 eV. The band gap value was increased when annealed at 80°C with 2.02 eV. Annealing temperatures were then raised to 120°C and 160°C, leading to band gap values of 3.11 eV and 2.80 eV respectively.

Development of CdS-SnO2 hybrid nanocomposite thin films for trace level detection of NO2 gas

In the present work, a novel sensor structure based on hybrid nanocomposite of tin oxide (SnO2) and cadmium sulphide (CdS) has been fabricated for trace level nitrogen dioxide (NO2) gas detection. CdS-SnO2 nanocomposite thin films derived from an optimized 3% concentration of CdS nanoparticles (NPs) infused colloidal solution of SnO2. For 10 ppm NO2 gas concentration CdS-SnO2 nanocomposite thin film based sensor structures exhibited a high sensing response of 2.8 × 103 together with quick response (16 s) and fast recovery time (29 s) respectively, at 90 °C. Sensing mechanism of enhanced NO2 sensitivity obtained in case of CdS-SnO2 nanocomposite thin films is explained in detail.

Influence of ZnO/TiO2 nanocomposite on optical and structural properties of OC1C10–PPV–DMP thin film

The photophysical properties of poly[2-methoxy-5-(3,7-dimethyl-octyloxy)-1,4-phenylenevinylene]—End capped with dimethylphenyl (DMP), OC1C10–PPV–DMP, were modified by incorporation various contents of the nanocomposites of both anatase TiO2 and wurtzite ZnO (ZTNCs). The solution blending method was employed to prepare the nanocomposite hybrids of OC1C10–PPV–DMP with ZTNCs before depositing them onto glass substrates. The optical parameters of the hybrid nanocomposite thin films were extracted from both absorption and photoluminescence spectra. XRD, FTIR, and FE-SEM revealed the good incorporation of ZTNC into the polymer matrix with the formation of a nanocomposite structure. By increasing the content of ZTNCs in the polymer matrix, the optical parameters of OC1C10–PPV–DMP such as energy band gap, energy tail, steepness parameter, and CIE chromatic coordinates were tuned. The incorporation of ZTNCs resulted in broadened and improved absorption and emission peaks of the polymer with a systematic shift for its corresponding maximum peaks. These unique findings are crucial for improving the performance of optoelectronic devices based on OC1C10–PPV–DMP/ZTNCs.

Tungsten-based hybrid nanocomposite thin film coated fabric for gamma, neutron, and X-ray attenuation

Ionizing radiation such as x-ray, γ-ray and neutron ray have serious negative health effects on human being. Hence, new and smart textile fabric nanocoating was facilely developed and coated on lab coat cloth. The newly hybrid nanocoatings were fabricated from uniform dispersion of PbWO4 NPs and Bi2WO6 NPs of an average sizes of 47.38 ± 7.6 and 9.1 ± 1.8 nm, respectively in chitosan solution. The dispersion of tungsten-based nanoparticles was performed using ultrasonication process, then well dispersed hybrid nanocoatings were coated on textile fabrics derived lab coat. The mass ratio of nanoparticles in nanocoatings were altered and optimized. The attenuation properties of x-ray/gamma ray and neutron ray were studied and achieving good shielding properties compared to uncoated fabrics. Additionally, the antibacterial and mechanical properties of coated fabrics were evaluated. The coated textile fabrics achieved clear inhibition zone of 4 mm compared to zero clear inhibition zone for uncoated ones against E-Coli. Moreover, the developed coating layer achieved good reinforcement effect recording superior tensile strength by 11.5% than uncoated sample. The dispersion properties of nanoparticles in coating nanocomposites were investigated using microscopic tools.

Preparation of hybrid conducting polymers blend nanocomposite for energy conversion using experimental data and TD-DFT/DMOl3 computations

In the presence of sodium dodecyl sulphate in an acidic solution while using ferric chloride as an oxidizing agent, a blend of three conducting polymers of poly (ortho-phenylene diamine) (PoPDA), poly (meta phenylene diamine), and polypyrrole was produced. ZrO2 nanoparticles were prepared via sol-gel method and a hybrid nanocomposite of the three conducting polymers blend and zirconium oxide nanoparticles (TCPB/ZrO2)HNC was synthesized. Using the Physical Vapor Deposition technology, a hybrid nanocomposite thin film was prepared from (TCPB/ZrO2)HNC. Density functional theory (DFT) was also used to develop optimization using TD-DFTD/Mol3 and Cambridge Serial Total Energy Bundle (TD-FDT/CASTEP). By closely matching the reported XRD and Raman spectra, the TD-DFT computations validated the molecular structure of the studied materials and confirmed its molecular structure. According to XRD calculations, (TCPB/ZrO2)HNC has an average crystallite size of 61.67 nm. The direct and indirect optical energy bandgaps for the (TCPB/ZrO2)HNC, are 2.352 and 2.253 eV, respectively. As measured by TD-DFT/DMol3, the isolated molecule of (TCPB/ZrO2) HNC has a bandgap of 2.415 eV. The optical properties suggested by CASTEP in TD-DFT agree quite well with the values obtained experimentally. The large optical energy bandgap of (TCPB/ZrO2)HNC is advantageous for various energy storage applications.

Docking of COVID-19 main protease and TD-DFT/DMOl3 simulated method, synthesis, and characterization with hybrid nanocomposite thin films and its applications

Using the precipitation polymerization method copolymer poly methyl methacrylate co acrylonitrile was synthesized. Hybrid nanocomposite thin films [P(MMA-co-AN)/ZnO]HNC were prepared using the dip casting method by adding ZnO nanoparticles by the ratios 0.25, 0.20, 0.15, and 0.10 according to the weight of P(MMA-co-AN). Fourier Transform Infrared Spectroscopy (FTIR), UV–Vis optical properties, and laser photoluminescence PL characterization techniques were used to study [P(MMA-co-AN)/ZnO]HNC films. In addition, density functional theory (DFT), optimization via TD-DFTD/Mol3, and Cambridge Serial Total Energy Bundle (TD-FDT/CASTEP) were used to perform the geometrical study. FTIR spectra from [P(MMA-co-AN)/ZnO]HNC indicates the interaction between the copolymer and ZnO nanoparticles. In the wavelength range of 190 – 800 nm, the optical properties of [P(MMA-co-AN)/ZnO]HNC were considered. The direct energy band gap was found to be changed from 4.1 eV for P (MMA – co – AN) to 3.19 eV for 0.25 ZnO, while the concentration of 0.20 ZnO was the highest in the Urbach energy with 0.17 eV. The refractive index nλ=700 ranges from 1.48 to 1.81 for the concentration of 0.15 ZnO. Three emission peaks at 393 nm, 527 nm, and 775 nm were figured in the laser photoluminescence spectra of [P(MMA-co-AN)/ZnO]HNC films. In order to attain the restrained action of studied ligands (hybrid nanocomposite) novel coronavirus (COVID 19) main protest (6LU7) molecular docking studies were performed. The predicted energy gab by TD-DFT/DMOl3 was found to be agreed with the experimental data in a good manner.

Synthesis and characterization of PVDF/PMMA/ZnO hybrid nanocomposite thin films for humidity sensor application

This work aimed PVDF/PMMA thin films in a range of ZnO NPs weight ratios that were successfully manufactured via spin coating as high-performance humidity sensors. The films have been characterized to calculate the structure, functional groups, transmittance and optical energy band gap. X-ray diffraction (XRD) structural studies reveal that the prepared films are polycrystalline with hexagonal crystal structures. It was found that the grain size of these films decreases with the increasing weight ratios of zinc oxide nanoparticles. Field emission scanning electron microscopy reveals the homogeneous distribution of zinc oxide nanoparticles in the PMMA/PVDF matrix. EDX was used to investigate the chemical composition of the PVDF/PMMA/ZnO nanocomposite. FTIR test was performed to identify the functional groups in the prepared samples as well as the detection of doping which is added to the samples. The optical energy band gap values were calculated and types of optical transmission and absorption of the films were determined from the optical transmittance spectra. The optical absorption studies in the wavelength range (200−700) nm show that energy band gap values of the prepared films decrease from (4.98–4.28) eV with increasing the ZnO NPs weight ratio. A sensor for relative humidity within the range (31−100) % RH was manufactured by studying the change of electrical properties (capacitive, resistance) and simulating them theoretically. It was found that the PVDF/PMMA/ZnO NPs nanocomposite is highly sensitive to humidity due to the high porosity of the material. The parameters of the sensors, such as response time and retrieval time, were also studied, and it was found that the manufactured sensors have acceptable values for these parameters.

Synthesis, structural and optical properties of Fungal biosynthesized Cu2O nanoparticles doped Poly methyl methacrylate -co- Acrylonitrile copolymer nanocomposite films using experimental data and TD-DFT/DMOl3 computations

A fungal mycelium-free extract was used to biosynthesize CuO2 nanoparticles from Fusarium oxysporum at 100 ppm of copper sulfate. A poly(acrylonitrile-co-methylmethacrylate) (P(AN-co-MMA)) was prepared by a precipitation polymerization method. A Cu2O nanoparticle was added by ratios of 0.25, 0.20, 0.15, and 0.10 to copolymer weight and then deposited on glass substrates by using the dip-casting method to form hybrid nanocomposite thin film [P(AN-co-MMA)/Cu2O]HNC. The structural properties of the [P(AN-co-MMA)/Cu2O]HNC films are studied by different characterization techniques such as X-Ray Diffraction XRD, UV-Vis optical properties, and laser photoluminescence PL. Additionally, using density functional theory (DFT), optimization via TD-DFTD/Mol3 and Cambridge Serial Total Energy Bundle (TD-FDT/CASTEP) was developed. The TD-DFT calculations accurately matched the observed XRD, and optical properties and validated the molecular structure of the examined materials. XRD pattern of the copolymer film shows that an amorphous structure is obtained. While a peak appeared at 2θ equal to 35.8º is for Cu2O nanoparticles. The average crystallite size of Cu2O nanocrystals and [P(AN-co-MMA)/Cu2O]HNC are about 78 nm and nm. Optical properties of the [P(AN-co-MMA)/Cu2O]HNC films at normal incidence of light in the wavelength range of 200–1100 nm are studied. The calculations of the direct energy gap show that it has changed from 4.15 eV for P(An-co-MMA) copolymer to 3.98 eV for 0.25 Cu2O nanocrystals loading. PL technique analyses indicated four emission peaks appeared at 398 nm, 455 nm, 518 nm, and 702 nm for the hybrid nanocomposites while only one peak at 398 nm appeared for P(An-co-MMA) copolymer. The optical characteristics predicted by CASTEP in TD-DFT are in good agreement with the experimental values. The obtained results indicate that the [P(An-co-MMA)/Cu2O]HNC film is a good candidate in electronic devices to block UV radiations based on its band gap and optical characteristics.

Physical structure, TD-DFT computations, and optical properties of hybrid nanocomposite thin film as optoelectronic devices

HCl doped-copolymer of ortho phenylene diamine and meta phenylene diamine was prepared by using oxidative polymerization method with ferric chloride as an oxidizing agent in the existence of sodium dedocyl sulphate as a soft template. The microporous structure thin films of hybrid copolymer/ZrO2 nanocomposite [copolymer/ZrO2]NC were fabricated using a physical vapor deposition (PVD) method. The effect of addition of zirconium oxide nanoparticles [ZrO2]NPs on the physical properties of the copolymer was discussed in the light of crystallinity and optical properties. The average crystallite size of [ZrO2]NPs is around 40 nm. The copolymer showed an absorbance of 1.18 at the wavelength (λ) 374 nm, which increased to 1.26 at λ = 440 nm after glycine addition, also increased to 1.53 at λ = 486 nm after [ZrO2]NPs loading. Also, the significant changes in the absorption index and indirect/direct bandgap of the copolymer have been detected. The materials Studio 7.0 program on TDDFT/DMol3 was used to optimize the molecular structure and perform the frequency calculations for the crystal models and isolated molecules. The DFT-Gaussian09W-vibration values are quite similar to the experimental data either in the structure or in the optical properties. The improvements in optical properties were achieved and revealed the possibility of using the hybrid nanocomposite films in the polymers solar cell application.

Characterization of As-prepared PVA-PEO/ZnO-Al2O3-NPs hybrid nanocomposite thin films

Characterization of As-prepared PVA-PEO/ZnO-Al2O3-NPs hybrid nanocomposite thin films

Enhancing Optical and Electrical Gas Sensing Properties of Polypyrrole Nanoplate by Dispersing Nano-Sized Tungsten Oxide

Pure polypyrrole (PPy) and tungsten oxide (WO3) nanostructures were produced and combined with specific ratios of WO3. to prepare PPy-WO3 hybrid nanocomposite thin films using the drop-casting process on a silicon substrate. The morphology of PPy, WO3, and PPy-WO3 was examined by field emission scanning electron microscopy and we found that the substance is nanoplates. Due to the quantum confinement effect, the optical energy gap of PPy increased from 3.58 eV to 3.92 and 4.21 eV upon incorporating 10 and 20% of WO3, respectively. At ambient temperature, the DC-conductivity of synthetic PPy was found to be 7.3 × 10−2 S cm−1 and this significantly increases when WO3 is added, which is accompanied by a change in the activation energies of the hybrid nanocomposite. The response and recovery times, as well as the sensitivity as a function of time and operating temperature, of pure PPy nanoplate and PPy-WO3 hybrid nanocomposites films for nitrogen dioxide (NO2) sensing were investigated. The PPy-WO3 hybrid nanocomposites exhibited a lower response time and higher sensitivity than pure PPy. The enhancement in the sensitivity of the PPy-WO3 hybrid nanocomposites to NO2 is ascribed to the synergistic effect between PPy and WO3.

Synthesis of Optically Tunable and Thermally Stable PMMA-PVA/CuO NPs Hybrid Nanocomposite Thin Films.

We report the synthesis and comprehensive characterization of polymethylmethacrylate (PMMA)/polyvinylalcohol (PVA) polymeric blend doped with different concentrations of Copper oxide (CuO) nanoparticles (NPs). The PMMA–PVA/CuO nanocomposite hybrid thin films containing wt.% = 0%, 2%, 4%, 8%, and 16% of CuO NPs are deposited on glass substrates via dip-coating technique. Key optical parameters are measured, analyzed, and interpreted. Tauc, Urbach, Spitzer–Fan, and Drude models are employed to calculate the optical bandgap energy (Eg) and the optoelectronic parameters of PMMA–PVA/CuO nanocomposites. The refractive index and Eg of undoped PMMA–PVA are found to be (1.5–1.85) and 4.101 eV, respectively. Incorporation of specific concentrations of CuO NPs into PMMA–PVA blend leads to a considerable decrease in Eg and to an increase of the refractive index. Moreover, Fourier Transform Infrared Spectroscopy (FTIR) transmittance spectra are measured and analyzed for undoped and doped polymeric thin films to pinpoint the major vibrational modes in the spectral range (500 and 4000 cm−1) as well as to elucidate the nature of chemical network bonding. Thermogravimetric analysis (TGA) is conducted under appropriate conditions to ensure the thermal stability of thin films. Doped polymeric thin films are found to be thermally stable below 105 °C. Therefore, controlled tuning of optoelectronic and thermal properties of doped polymeric thin films by introducing an appropriate concentration of inorganic fillers leads to a smart design of scaled multifunctional devices.

Synthesis of a novel coumarin heterocyclic derivative and fabrication of hybrid nanocomposite thin film with CoOFe2O4 for optoelectronic applications

Novel synthesis of 3-(2-oxo-2H-chromene-3-yl) quinoxaline-2(1H)-one nanostructured thin film [3OCQ]TF has been developed. Its compositional, structural flexibility, tunable bandgap, high quantum photoluminescence yields, optical and electronic properties have been explored. While the progress of these properties has been studied recently, the roots of electronic transition in different kinds of organic nano- semiconductors [3OCQ] remain unclear. In this investigation, we explored the photon transfer between a single 3D and null dimensional [3OCQ] and the hybrid nanocomposite of coumarin derivatives thin film [3OCQ/CoOFe2O4]HC. Using DFT simulation, the structure measurements can determine the energy gap and optical properties of [3OCQ] and [3OCQ/CoOFe2O4]HC. They are more comparable than conventional semiconductors to individual molecular quinoxaline. The obtained DFT data provide good proof for the electronic transition in zero-dimensional [3OCQ] and [3OCQ/CoOFe2O4]HC. This study provides valuable information on the nature and sources of defect formation and electronic transition in organic nano-semiconductor [3OCQ]TF and [3OCQ/CoOFe2O4]HC which open the way for the application as an optoelectronic device. Photoluminescence measurements showed enhanced, red-shifted fluorescence intensities for the fluorophore [3OCQ] with the addition of Cobalt Ferrite [CoOFe2O4] nanoparticles. This can be attributed to the effect of the transition of fluorescent resonance energy and the overlap of the fluorophore emission band with metal nanoparticles resonance surface plasmon bands. The results specifically determine that ΔEgOpt values decrease from 2.348 eV for [3OCQ]TF to 1.549 eV for [3OCQ/CoOFe2O4]HC using the DFT computations HOMO and LUMO calculation. This result concluded that the [3OCQ]TF transformed from semiconductor to [3OCQ/CoOFe2O4]HC as a superconductor hybrid nanocomposite by the addition of (CoOFe2O4 nanoparticles).

Influence of hydrogen sulfide gas concentrations on LOD and LOQ of thermal spray coated hybrid-bacterial cellulose film for intelligent meat label

Hybrid nanocomposite thin film for hydrogen sulfide (H2S) gas sensor based on bacterial cellulose nanocrystals (BCNCs) has resulted in high demand of environmentally friendly nanomaterials. Films were prepared using thermal spray coating that sprayed hybrid nanocomposite suspension based on silver nanoparticles (AgNPs)-loaded BCNCs’s surface and alginate-molybdenum trioxide (MoO3NPs) onto PET substratum. In this study, a novel food package label characterized as H2S gas sensor for meat spoilage is based on an optically transparent coated film with thickness ranging from 0.73 to 2.18 μm. Sensor characteristics with different suspension concentrations and various H2S gas concentrations were evaluated. The highest sensitivity to H2S with the limit of detection (LOD) (3.27 ppm) and the limit of quantification (LOQ) (10.94 ppm) was exhibited in 1%w/v suspension. Label prototypes which respond as visible color changes through naked-eye to H2S gas released during meat spoilage, monitored at 4 °C and varying storage times were conducted.

Ion beam engineering in WO3-PEDOT: PSS hybrid nanocomposite thin films for gas sensing measurement at room temperature

This work focus upon influence of low energy ion beam irradiation on the physico-chemical, structural and optical properties of (Glass/WO3-PEDOT: PSS) hybrid thin films. The hybrid nanocomposites were synthesized by uniform dispersion of 1 wt% and 5 wt% WO3 nanoparticles in PEDOT: PSS conducting polymer solution. The hybrid films were irradiated with low energy Ar4+ (700 keV) beam at fluence 1 × 1015 ions.cm−2 and 1 × 1016 ions.cm−2 in IUAC, New Delhi, India. The particle size was determined to be 63 nm–33 nm (1 wt% hybrid film) and 62–61 nm (5 wt% hybrid film) using Scherer’s formula. The band gap for pristine and irradiated films of 1 wt% (2.34–2.18 eV) and 5 wt% (2.39–2.14 eV) were calculated from Tauc’s relation. FTIR and Raman spectroscopy analysis confirmed the formation of chemical bonds and carbonization of film at higher fluences. The change in properties of hybrid nanocomposite material by ion irradiation may be useful for sensing applications. The sensor response of pristine and irradiated hybrid composite films was studied from liquefied petroleum gas (LPG) at room temperature.

Thin Films Based on Cobalt Phthalocyanine:C60 Fullerene:ZnO Hybrid Nanocomposite Obtained by Laser Evaporation.

Matrix-assisted pulsed laser evaporation (MAPLE) was used to deposit hybrid nanocomposite thin films based on cobalt phthalocyanine (CoPc), C60 fullerene and ZnO nanoparticles. The inorganic nanoparticles, with a size of about 20 nm, having the structural and optical properties characteristic of ZnO, were chemically synthesized by a simple precipitation method. Furthermore, ZnO nanoparticles were dispersed in a dimethyl sulfoxide solution in which CoPc and C60 had been dissolved, ready for the freezing MAPLE target. The effect of the concentration of ZnO nanoparticles on the structural, morphological, optical and electrical properties of the CoPc:C60:ZnO hybrid nanocomposite layers deposited by MAPLE was evaluated. The infrared spectra of the hybrid nanocomposite films confirm that the CoPc and C60 preserve their chemical structure during the laser deposition process. The CoPc optical signature is recognized in the ultraviolet–visible (UV–Vis) spectra of the obtained layers, these being dominated by the absorption bands associated to this organic compound while the ZnO optical fingerprint is identified in the photoluminescence spectra of the prepared layers, these disclosing the emission bands linked to this inorganic semiconductor. The hybrid nanocomposite layers exhibit globular morphology, which is typical for the thin films deposited by MAPLE. Current-voltage (J-V) characteristics of the structures developed on CoPc:C60:ZnO layers reveal that the addition of an appropriate amount of ZnO nanoparticles in the CoPc:C60 mixture leads to a more efficient charge transfer between the organic and inorganic components. Due to their photovoltaic effect, structures featuring such hybrid nanocomposite thin films deposited by MAPLE can have potential applications in the field of photovoltaic devices.

Low power consumption and fast response H2S gas sensor based on a chitosan-CuO hybrid nanocomposite thin film

In this work, a novel selective and low temperature H2S gas sensor was fabricated based on copper (II) oxide nanoparticles (CuO NPs) in different concentrations, embedded in a conductivity-engineered organic (glycerol ionic liquid-doped chitosan) membrane/film. The sensing membranes of organic-inorganic nanocomposites (CS-IL-CuO) were prepared by casting method and were tested against H2S gas with reference to time at different temperatures and H2S gas concentrations. The fabricated sensor showed a fast response (14 s) and good sensitivity (15 ppm) towards H2S gas at a low temperature of 40 °C. Moreover, the sensor showed a high reversibility and less humidity dependence at 40 °C. Moreover, this type of hybrid nanocomposites sensor is easy and inexpensive to manufacture and is energy efficient. Thus, it has potential to be used for industrial applications in harsh environments.

Performance of Graphene-CdS Hybrid Nanocomposite Thin Film for Applications in Cu(In,Ga)Se2 Solar Cell and H2 Production.

A graphene–cadmium sulfide (Gr–CdS) nanocomposite was prepared by a chemical solution method, and its material properties were characterized by several analysis techniques. The synthesized pure CdS nanoparticles (NPs) and Gr–CdS nanocomposites were confirmed to have a stoichiometric atomic ratio (Cd/S = 1:1). The Cd 3d and S 2p peaks of the Gr–CdS nanocomposite appeared at lower binding energies compared to those of the pure CdS NPs according to X-ray photoelectron spectroscopy analyses. The formation of the Gr–CdS nanocomposite was also evidenced by the structural analysis using Raman spectroscopy and X-ray diffraction. Transmission electron microscopy confirmed that CdS NPs were uniformly distributed on the graphene sheets. The absorption spectra of both the Gr–CdS nanocomposite and pure CdS NPs thin films showed an absorption edge at 550 nm related to the energy band gap of CdS (~2.42 eV). The Cu(In,Ga)Se2 thin film photovoltaic device with Gr–CdS nanocomposite buffer layer showed a higher electrical conversion efficiency than that with pure CdS NPs thin film buffer layer. In addition, the water splitting efficiency of the Gr–CdS nanocomposite was almost three times higher than that of pure CdS NPs.

Nanoclay decorated polyacrylic acid/starch hybrid nanocomposite thin films as packaging materials

Nanoclay reinforced starch‐co‐PAA hybrid nanocomposite thin films are synthesized by in situ polymerization technique in aqueous solution. The interactions of clay with starch‐co‐PAA are studied by Fourier transform infrared spectroscopy (FTIR) and X‐ray diffraction (XRD). The morphology of nanoclay platelets in starch‐co‐PAA hybrid nanocomposite thin film is studied by scanning electron microscope (SEM) and high‐resolution transmission electron microscope (HRTEM) images are used to investigate micro and nanostructural behavior of clay platelets in starch‐co‐PAA matrix. It is noticed that, the thin film has an exfoliated structure at 3 wt% clay loading whereas; clay platelets are agglomerated in higher percentage of clay. The synthesized materials have chemical resistance of 22% more than the virgin matrix. The biodegradable properties of the nanocomposite thin films are reduced by 20% due to incorporation of nanoclay. The oxygen barrier property of starch‐co‐PAA/clay thin film is reduced by seven folds as compared to starch‐co‐PAA. From the measurement of refractive indexes, it is found that, the transparency of the nanocomposite thin films are reduced by around 10% by reinforcement of nanoclay. The results show a substantial enhancement in oxygen barrier property and reduction of refractive index on clay loading, which may permit the synthesized materials suitable for packaging applications. POLYM. COMPOS., 40:229–239, 2019. © 2017 Society of Plastics Engineers