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AIP Conference Proceedings [Author(s) INTERNATIONAL CONFERENCE ON INVENTIVE MATERIAL SCIENCE APPLICATIONS: ICIMA-2018 - Tamil Nadu, India (27–28 September 2018)] - The effect of the ZnO thickness layer on the porous silicon properties deposited by chemical vapor deposition
摘要： We report on the properties of porous silicon deposited by Electro-Chemical Etching (ECE) technique with ZnO nanoparticles layer grown on porous silicon (P-type) by Chemical Vapor Deposition (CVD). X-ray diffraction study on the crystallographic structure revealed a beneficial impact of ZnO films on the structural properties of the porous silicon. Moreover, these properties enhanced when the ZnO layer thickness was increased. The morphological properties of ZnO/PSi were investigated based on Atomic Force Microscopy (AFM) and Scanning Electron Microscopy (SEM) measurements. The results indicate an upgrading in the structural stability of PSi substrate with crystalline growth of ZnO thin film. It is also observed that the value of the roughness (RMS) increases when ZnO filme on PSi increases. All these results indicate that the interested ZnO shows a good and homogenous layer using (CVD) technique. Finally, it is evident that porous silicon substrate can open the door for improving the crystalline quality in hexagonal lattice of ZnO thin film, and this could be due to sponge-like structure of porous silicon.
关键词： ZnO,porous silicon,SEM,Chemical Vapor Deposition,AFM,Electro-Chemical Etching,XRD
更新于2025-09-10 09:29:36
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Photocatalytic Studies of Tio2/Sio2 Nanocomposite Xerogels
摘要： The use of titania-silica materials in photocatalytic processes has been proposed as an alternative to the conventional TiO2 catalysts, in order to facilitate the separation of products after the reaction. However, despite the large number of research in this field, the mechanism governing the photocatalytic activity of the mixed TiO2/SiO2 oxides is not clear. Titania-Silica nanocomposite xerogels were prepared by sol-gel method. This work has been used to describe the synthesis and the photocatalytic properties of TiO2-SiO2 nanocomposite xerogel. The nanocomposite xerogels were prepared by keeping the molar ratio of TEOS:TTIP:MtOH:DIW at 1: 1:6:14 respectively and the catalysts used were HCl and NH4OH. After the preparation xerogels were characterized by FTIR, XRD, UV and LLS. All these techniques show the amorphous nature of Titania-silica xerogel.
关键词： UV,FTIR,Photocatalysis,TiO2-SiO2 mixed oxide,LLS,XRD
更新于2025-09-10 09:29:36
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Exploring aggregation-induced emission through tuning of ligand structure for picomolar detection of pyrene
摘要： Tuning of ligand structures through controlled variation of ring number in fused‐ring aromatic moiety appended to antipyrine allows detection of 7.8 × 10?12 M pyrene via aggregation‐induced emission (AIE) associated with 101‐fold fluorescence enhancement. In one case, antipyrine unit is replaced by pyridine to derive bis‐methylanthracenyl picolyl amine. The structures of four molecules have been confirmed by single crystal X‐ray diffraction analysis. Among them, pyrene‐antipyrine conjugate (L) undergoes pyrene triggered inhibition of photo‐induced electron transfer (PET) leading to water‐assisted AIE.
关键词： pyrene,AIE,sensor,SPE,SC‐XRD
更新于2025-09-10 09:29:36
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Determination of Sulfite in Botanical Medicine Using Headspace Thin-Film Microextraction and Surface Enhanced Raman Spectrometry
摘要： A facile method using headspace thin-film microextraction (HS-TFME) coupled with surface enhanced Raman spectrometry (SERS) has been developed for the determination of sulfite in traditional Chinese herbal medicine. The extraction substrate was synthesized by depositing urchin-like ZnO micron particles on glass sheets using chemical liquid phase deposition. Under the optimal conditions, the intensity of the SERS signal at 630–640 cm?1 provided a good linear relationship with the concentration of sulfite from 25 to 400 mg/kg, and the linear correlation coefficient (R) was 0.996 with a detection limit of 6 mg/kg. The method was employed for the determination of sulfite in herbal medicines, and the results were confirmed by a traditional distillation-titration method. Therefore, this developed HS-TFME-SERS method may play an important role in the rapid, simple, and selective determination of sulfite residues in Chinese herbal medicine and become a potentially universal method for this analyte in various solid samples.
关键词： Headspace thin-film microextraction (HS-TFME),scanning electron microscopy (SEM),X-ray diffraction (XRD),surface enhanced Raman spectrometry (SERS),transmission electron microscopy (TEM)
更新于2025-09-10 09:29:36
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Structural and optical properties of metallic doped Palladium Sulfide thin films
摘要： The Addition of impurities and the nature of substrate are known to change the properties of any deposited thin films. In this work, the influence of doping on the structural and optical properties of PdS thin films grown by chemical bath method has been studied. Aluminum (Al) was used as the dopant for PdS thin films deposited at room temperature. Band gap energy (??g), and other optical parameters were determined from the optical transmission of the film. The estimated energy band gap for the films varied from 1.50 to 1.80 eV. Nanocrystal PdS thin films exhibited a tetragonal structure with average crystallite size of 60 nm. The results obtained prove that doping have profound and superficial effects on optical and structural properties of the deposited PdS thin films.
关键词： Doping,PdS,Optical Properties,Semiconductor,XRD
更新于2025-09-10 09:29:36
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Annealing effects on properties of Ga2O3 films deposited by plasma-enhanced atomic layer deposition
摘要： We investigated annealing effects on the Ga2O3 thin films deposited on c-sapphire by plasma-enhanced atomic layer deposition. A metastable Ga2O3 films was deposited on c-sapphire substrate by PEALD with high plasma power at 250 °C. The (2?0?1) preferred orientation b-Ga2O3 films were obtained after annealing in oxygen atmosphere. Structure and surface analysis revealed that the annealed films had more fine-grained surface features. The film annealed for 2 h exhibited the best crystallinity. The bandgap of the as-deposited and annealed films for 2 h were 4.56 and 4.97 eV, respectively. The process of high-temperature annealing contributed gallium, oxygen atoms to obtain enough energy to migrate to the suitable location and increased the vigilance of crystallinity.
关键词： Thin films,Ga2O3,Epitaxial growth,XRD,Annealing
更新于2025-09-10 09:29:36
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Preparation and characterization of graphene – TiO2 nanocomposite for enhanced photodegradation of Rhodamine-B dye
摘要： The synthesizing of TiO2@rGO nanocomposites using an efficient method has been carried out to enhance the photodegradation activities of TiO2. Reduced graphene oxide (rGO) synthesis has been illustrated as a key step. The preparation of TiO2@rGO is highly needed and recommended to develop an effective way for the reduction of GO. Our study illustrated an environmentally simple method for TiO2@rGO preparation and demonstrated its efficiency for photocatalytic process by utilizing rhodamine-B dye as an organic pollutant. Synthesized nanoparticles of reduced TiO2@rGO have an observable increase in photo-energy adsorption leading to the increase of the photodegradation reactions. From the obtained results, TiO2@rGO nanocomposites showed great ability to absorb photo-energy and enhance the photodegradation reactions. Moreover, the results revealed that the 3% TiO2@rGO have the best performance than 1% TiO2@rGO at pH = 9.0, 30 mg/l initial dye concentration and 60 min irradiation duration. The reduced graphene oxide production was considered as an influential co-catalyst for improving the TiO2 photocatalytic activities mainly owing to; the fast separation of h+/e? and the adsorption improvement. Our study affirms the production of promising applicable particles using the environmental photocatalysis process in particular with regard to wastewater purification.
关键词： Photocatalysis,Graphene oxide,Nanocomposite,TEM,Rh-B dye,TiO2,XRD
更新于2025-09-10 09:29:36
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Molecular structure characterization of middle-high rank coal via XRD, Raman and FTIR spectroscopy: Implications for coalification
摘要： In recent years, the major coal producing areas in China have entered the period of deep mining, with coal rank changing from low-rank coal (LRC) to middle-high rank coal (MHRC). Even though material properties of MHRC, such as pore size and shape, have attracted increasing attentions, its molecular structures still remains unclear. This study probes molecular structural properties of five MHRC samples using X-ray diffraction (XRD), Raman and Fourier transform infrared (FTIR) spectroscopy. Test results show that with the deepening of coalification, the aromatic rings of MHRC increase gradually. The aliphatic side chains between the aromatic rings continuously fall off. The ordered structure of coal continues to enhance, resulting in an increase in the degree of graphitization of coal. The average lateral sizes (La), stacking heights (Lc) and interlayer spacing (d002) of the crystallite structures of MHRC samples derived from the XRD range from 20.65 to 31.68, 10.62 to 19.21 and 3.42 to 3.66 ?, respectively. The La values derived from the Raman spectra using the classical linear relationship between 1/La and the ID1/IG band ratio are higher (36.36–59.91 ?) than the values obtained from XRD. The FTIR spectra reveals that MHRC samples contain aliphatic functional groups such as eCH2 and eCH3, aromatic functional groups such as C]C and aromatic ring eCH, and oxygen-containing functional groups such as eOH, C]O and CeO. The aromaticity (fa) of the coal samples determined by FTIR ranges from 0.66 to 0.98, and compared with the fa valued from XRD (0.63 to 0.93), which shows that the MHRC contains abundant of aliphatic components. On the basis of these results, the structural parameters obtained by different spectral techniques are also used to comparatively study the effects of coalification on the molecular structure of coals. The structural parameters of coal derived by these methods reflect the coalification jumps at Ro = 0.5, 0.7–0.9, 1.2, 2.6, 3.3, 3.5–4.0 and 4.2–4.8%. Among them, the jump at Ro = 4.2–4.8% is unreported in previous studies and should be further studied in subsequent research. The application range of structure parameters used to evaluate the coal rank such as d002, La (XRD), fa and G-D1 should be considered because of coalification jumps. The parameters such as 'C', ID1/IG and La (Raman) are better choices for evaluating coal rank for their better correlation with Ro. It is worth pointing out that these parameters have implications for coalification and should be concerned in further study.
关键词： FTIR,Molecular structure,Raman,Coalification jump,Middle-high rank coal,XRD
更新于2025-09-10 09:29:36
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Novel tris-buffer based Schiff base bearing long flexible alkoxy arm and its lanthanide complexes: mesomorphism and photoluminescence
摘要： A new liquid crystalline salicylaldimine Schiff base having pendant hydroxymethyl (-CH2OH) groups and a series of lanthanide(III) complexes of the type, [Ln(LH)3(NO3)3] {Ln= La, Pr, Sm, Gd, Tb; LH=(E)-2-((1, 3-dihydroxy-2-(hydroxyl methyl) propan- 2-ylimino)methyl)-5-(hexadecyloxy) phenol} have been synthesised. The compounds were characterised by FT-IR, 1H NMR, 13C NMR, UV-Vis, and FAB-mass spectroscopy. Thermal behaviour of these compounds was studied using polarizing optical microscopy (POM) and differential scanning calorimetry. The phase confirmation and molecular organisation in the mesophase was ascertained by variable temperature powder X-ray diffraction (XRD) study. The ligand and the complexes both showed highly viscous smecticA and columnar mesophase, respectively. A bilayer self organization of the ligand molecules with interdigitation of the alkyl chains in the mesophase is proposed. Molecular organizations of the complexes in the mesophase involve arrangement of all the aliphatic chain pointing in same direction leading to lamellar columnar phase. The ligand showed an intense blue emission at 452 nm while the gadolinium(III) complex exhibited an intense emission at 458 nm (λex= 310 nm). The samarium(III) complex is a bright orange light emitter over a wide range upon UV irradiation.
关键词： mesophase,Schiff base,lanthanidomesogen,Luminescent,XRD
更新于2025-09-10 09:29:36
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The effect of CdO content on the crystal structure, surface morphology, optical properties and photocatalytic efficiency of p-NiO/n-CdO nanocomposite
摘要： Pure NiO nanoparticles and NiO-CdO nanocomposite were prepared with different content of CdO by simple chemical precipitation method at 800 °C for 3 h. Crystal structure, surface morphology, elemental composition and function groups present in the prepared samples were characterized by XRD, SEM, EDX, Raman and FTIR analysis, respectively. From XRD, preparation of pure NiO and formation of nanocomposite samples confirmed by the presence of characteristic diffraction peaks of cubic phase structure of NiO and CdO. The particle size increases from 26 to 34 nm with the increase of CdO content in the prepared samples. SEM images show the spherical shape of NiO and plate like shape of nanocomposite samples. The EDX analysis revealed that the absence of any impurity peaks indicates the high quality of prepared samples. Raman and FTIR spectra show the fundamental peaks of NiO and CdO in the samples. The best photodegradation efficiency of methyl orange dye i.e. 60% was achieved as a result of the decrease in the energy band gap from 3.42 to 2.92 eV at the optimum content of CdO (0.12 wt.%).
关键词： Photocatalytic efficiency,Raman analysis,Nanocomposite,Optical properties,XRD
更新于2025-09-10 09:29:36