scholarly journals Structural, Surface Morphology and Optical Properties of ZnS Films by Chemical Bath Deposition at Various Zn/S Molar Ratios

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Fei-Peng Yu ◽  
Sin-Liang Ou ◽  
Pin-Chuan Yao ◽  
Bing-Rui Wu ◽  
Dong-Sing Wuu
Keyword(s):  
Chemical Bath Deposition ◽  
Photoelectron Spectroscopy ◽  
Visible Region ◽  
Film Surface ◽  
Optical Transmittance ◽  
Molar Ratio ◽  
Infrared Spectrometry ◽  
X Ray ◽  
Molar Ratios ◽  
Zns Films

In this study, ZnS thin films were prepared on glass substrates by chemical bath deposition at various Zn/S molar ratios from 1/50 to 1/150. The effects of Zn/S molar ratio in precursor on the characteristics of ZnS films were demonstrated by X-ray diffraction, scanning electron microscopy, optical transmittance, X-ray photoelectron spectroscopy, and Fourier transform infrared spectrometry. It was found that more voids were formed in the ZnS film prepared using the precursor with Zn/S molar ratio of 1/50, and the other ZnS films showed the denser structure as the molar ratio was decreased from 1/75 to 1/150. From the analyses of chemical bonding states, the ZnS phase was indeed formed in these films. Moreover, the ZnO and Zn(OH)2also appeared due to the water absorption on film surface during deposition. This would be helpful to the junction in cell device. With changing the Zn/S molar ratio from 1/75 to 1/150, the ZnS films demonstrate high transmittance of 75–88% in the visible region, indicating the films are potentially useful in photovoltaic applications.

scholarly journals Photocatalytic Reduction of CO2 to Methanol Using a Copper-Zirconia Imidazolate Framework

Catalysts ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 346
Author(s):  
Sonam Goyal ◽  
Maizatul Shima Shaharun ◽  
Ganaga Suriya Jayabal ◽  
Chong Fai Kait ◽  
Bawadi Abdullah ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Catalyst Support ◽  
Oxidation Potential ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
X Ray ◽  
Molar Ratios ◽  
Optimum Parameters ◽  
Reduction Of Co2 ◽  
Enhanced Yield

A set of novel photocatalysts, i.e., copper-zirconia imidazolate (CuZrIm) frameworks, were synthesized using different zirconia molar ratios (i.e., 0.5, 1, and 1.5 mmol). The photoreduction process of CO2 to methanol in a continuous-flow stirred photoreactor at pressure and temperature of 1 atm and 25 °C, respectively, was studied. The physicochemical properties of the synthesized catalysts were studied using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and photoluminescence (PL) spectroscopy. The highest methanol activity of 818.59 µmol/L.g was recorded when the CuZrIm1 catalyst with Cu/Zr/Im/NH4OH molar ratio of 2:1:4:2 (mmol/mmol/mmol/M) was employed. The enhanced yield is attributed to the presence of Cu2+ oxidation state and the uniformly dispersed active metals. The response surface methodology (RSM) was used to optimize the reaction parameters. The predicted results agreed well with the experimental ones with the correlation coefficient (R2) of 0.99. The optimization results showed that the highest methanol activity of 1054 µmol/L.g was recorded when the optimum parameters were employed, i.e., stirring rate (540 rpm), intensity of light (275 W/m2) and photocatalyst loading (1.3 g/L). The redox potential value for the CuZrIm1 shows that the reduction potential is −1.70 V and the oxidation potential is +1.28 V for the photoreduction of CO2 to methanol. The current work has established the potential utilization of the imidazolate framework as catalyst support for the photoreduction of CO2 to methanol.

scholarly journals Growth of Polycrystalline In2S3 Thin Films by Chemical Bath Deposition Using Acetic Acid as a Complexing Agent for Solar Cell Application

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
G. R. Gopinath ◽  
K. T. Ramakrishna Reddy
Keyword(s):  
Acetic Acid ◽  
Solar Cell ◽  
Chemical Bath Deposition ◽  
Visible Region ◽  
Optical Transmittance ◽  
Xrd Analysis ◽  
Complexing Agent ◽  
Solar Cell Application ◽  
X Ray ◽  
Glass Substrates

In2S3 films have been successfully deposited on Corning glass substrates via chemical bath deposition (CBD) method using acetic acid as a novel complexing agent. The layers were grown by employing synthesis using indium sulphate and thioacetamide (TA) as precursors by varying TA concentration in the range of 0.1–0.5 M, keeping other deposition parameters constant. Energy dispersive X-ray analysis (EDAX) revealed an increase of S/In ratio in the films with the increase of TA concentration in the solution. The X-ray diffraction (XRD) analysis indicated a change in preferred orientation from (311) plane related to cubic structure to the (103) direction corresponding to the tetragonal crystal structure. The evaluated crystallite size varied in the range of 15–25 nm with the increase of TA concentration. Morphological analysis showed that the granular structure and the granular density decrease with the raise of TA concentration. The optical properties of the layers were also investigated using UV-Vis-NIR analysis, which indicated that all the In2S3 films had the optical transmittance >60% in the visible region, and the evaluated energy band varied in the range of 2.87–3.32 eV with the change of TA concentration. Further, a thin film heterojunction solar cell was fabricated using a novel absorber layer, SnS, with In2S3 as a buffer. The unoptimized SnS/In2S3/ZnO:Al solar cell showed a conversion efficiency of 0.6%.

scholarly journals Effects of Deposition Time on the Morphology, Structure, and Optical Properties of PbS Thin Films Prepared by Chemical Bath Deposition

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
B. Abdallah ◽  
A. Ismail ◽  
H. Kashoua ◽  
W. Zetoun
Keyword(s):  
Thin Films ◽  
Chemical Bath Deposition ◽  
Photoelectron Spectroscopy ◽  
Deposition Time ◽  
Optical Band Gap ◽  
Optical Transmittance ◽  
Xrd Analysis ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force

Lead sulfide thin films were prepared by chemical bath deposition (CBD) on both glass and Si (100) substrates. XRD analysis of the PbS film deposited at 25°C showed that the prepared films have a polycrystalline structure with (200) preferential orientation. Larger grains could be obtained by increasing the deposition time. The prepared films were also chemically characterized using X-ray photoelectron spectroscopy (XPS), which confirmed the presence of lead and sulfur as PbS. While energy dispersive X-ray spectroscopy (EDX) technique was used to verify the stoichiometry of the prepared films. Atomic force microscopy (AFM) was used to study the change in the films’ morphology with the deposition time. The effect of the deposition time, on both optical transmittance in the UV-Vis-NIR region and the structure of the film, was studied. The obtained results demonstrated that the optical band gap decreased when the thickness increased.

scholarly journals Zn-Al Mixed Oxides Decorated with Potassium as Catalysts for HT-WGS: Preparation and Properties

Catalysts ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1094 ◽  
Author(s):  
Katarzyna Antoniak-Jurak ◽  
Paweł Kowalik ◽  
Kamila Michalska ◽  
Wiesław Próchniak ◽  
Robert Bicki
Keyword(s):  
Photoelectron Spectroscopy ◽  
Mixed Oxides ◽  
Catalyst Activity ◽  
Molar Ratio ◽  
X Ray ◽  
Molar Ratios ◽  
Mixed Oxide Catalysts ◽  
Wgs Reaction ◽  
Temperature Programmed ◽  
Co Precipitation

A set of ex-ZnAl-LDHs catalysts with a molar ratio of Zn/Al in the range of 0.3–1.0 was prepared using co-precipitation and thermal treatment. The samples were characterized using various methods, including X-ray fluorescence spectroscopy (XRF), X-ray photoelectron spectroscopy (XPS), X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy FT-IR, N2 adsorption, Temperature-programmed desorption of CO2 (TPD-CO2) as well as Scanning electron microscopy (SEM-EDS). Catalyst activity and long-term stability measurements were carried out in a high-temperature water–gas shift (HT-WGS) reaction. Mixed oxide catalysts with various Zn/Al molar ratios decorated with potassium showed high activity in the HT-WGS reaction within the temperature range of 330–400 °C. The highest activity was found for the Zn/Al molar ratio of 0.5 corresponding to spinel stoichiometry. However, the catalyst with a stoichiometric spinel molar ratio of Zn/Al (ZnAl_0.5_K) revealed a higher tendency for surface migration and/or vaporization of potassium during overheating at 450 °C. The correlation of the activity results and TPD-CO2 data show that medium basic sites enhance the progress of the HT-WGS reaction.

Sol-gel Synthesis of Li–ZrSiO4

2000 ◽  
Vol 15 (7) ◽  
pp. 1490-1495 ◽  
Author(s):  
Heriberto Pfeiffer ◽  
Pedro Bosch ◽  
Jose A. Odriozola ◽  
Alberto Lopez ◽  
Jorge A. Ascencio ◽  
...  
Keyword(s):  
Theoretical Analysis ◽  
Photoelectron Spectroscopy ◽  
Sol Gel ◽  
Molar Ratio ◽  
Spectroscopy Analysis ◽  
Gel Method ◽  
X Ray ◽  
Cell Parameters ◽  
Molar Ratios ◽  
Sol Gel Synthesis

Li–ZrSiO4 was synthesized by the sol-gel method. Reactions were performed with different Li:Zr molar ratios: 1, 3, 5, and 6. Cell parameters changed as follows: a0 decreased and c0 increased as the Li:Zr molar ratio increased. The x-ray photoelectron spectroscopy analysis showed two kinds of oxygen atoms. The first one was attributed to ZrSiO4 oxygens. The second one was attributed to Li–O bonds. All these results were supported by a theoretical analysis. It was concluded that lithium atoms were held in interstitial positions of the ZrSiO4 structure.

scholarly journals Surface Stoichiometry and Depth Profile of Tix-CuyNz Thin Films Deposited by Magnetron Sputtering

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3191
Author(s):  
Arun Kumar Mukhopadhyay ◽  
Avishek Roy ◽  
Gourab Bhattacharjee ◽  
Sadhan Chandra Das ◽  
Abhijit Majumdar ◽  
...  
Keyword(s):  
Magnetron Sputtering ◽  
Photoelectron Spectroscopy ◽  
Film Surface ◽  
Grazing Incidence ◽  
X Ray Diffraction ◽  
X Ray ◽  
Relative Composition ◽  
Transmission Electron ◽  
Deposited Film ◽  
Deposited Films

We report the surface stoichiometry of Tix-CuyNz thin film as a function of film depth. Films are deposited by high power impulse (HiPIMS) and DC magnetron sputtering (DCMS). The composition of Ti, Cu, and N in the deposited film is investigated by X-ray photoelectron spectroscopy (XPS). At a larger depth, the relative composition of Cu and Ti in the film is increased compared to the surface. The amount of adventitious carbon which is present on the film surface strongly decreases with film depth. Deposited films also contain a significant amount of oxygen whose origin is not fully clear. Grazing incidence X-ray diffraction (GIXD) shows a Cu3N phase on the surface, while transmission electron microscopy (TEM) indicates a polycrystalline structure and the presence of a Ti3CuN phase.

Low-temperature route to nanoscale P3N5 hollow spheres

2003 ◽  
Vol 18 (10) ◽  
pp. 2359-2363 ◽  
Author(s):  
Hongzhou Gu ◽  
Yunle Gu ◽  
Zhefeng Li ◽  
Yongcheng Ying ◽  
Yitai Qian
Keyword(s):  
Photoelectron Spectroscopy ◽  
Hollow Spheres ◽  
Molar Ratio ◽  
Visible Absorption ◽  
X Ray ◽  
Transmission Electron ◽  
Influence Of Temperature On ◽  
Wide Gap ◽  
20 Nm ◽  
High Degree

Nanoscale hollow spheres of amorphous phosphorus nitride (P3N5) were synthesized by reacting PCl3 with NaN3 at 150–250 °C. Transmission electron microscope images show that the hollow spheres have a diameter of 150–350 nm, and the thickness of the shell is 20 nm. A very small amount of curly films were also found in the sample prepared at 150 °C. The infrared spectrum indicates a high degree of purity. X-ray photoelectron spectroscopy indicates the presence of P and N, with a molar ratio of 1:1.62 for P:N. Ultraviolet-visible absorption spectroscopy shows an absorption band at 265–315 nm. Under photoluminescent excitation at 230 nm, the P3N5 emits ultraviolet light at 305 nm. With a band gap of 4.28 eV, the products may be a wide gap semiconductor. A possible mechanism and the influence of temperature on the formation of the hollow spheres are also discussed.

scholarly journals Photocatalytic activity of Cu2O/ZnO nanocomposite for the decomposition of methyl orange under visible light irradiation

2019 ◽  
Vol 26 (1) ◽  
pp. 104-113 ◽  
Author(s):  
Xian-sheng Wang ◽  
Yu-duo Zhang ◽  
Qiao-chu Wang ◽  
Bo Dong ◽  
Yan-jia Wang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Methyl Orange ◽  
Photoelectron Spectroscopy ◽  
Visible Region ◽  
Methyl Orange Solution ◽  
Degradation Efficiency ◽  
X Ray ◽  
Transmission Electron ◽  
Consistent Performance ◽  
Two Phases

AbstractZnO is modified by Cu2O by the process of precipitation and calcination. X-ray diffraction has shown that Cu2O/ZnO catalysts are made of highly purified cubic Cu2O and hexagonal ZnO. Scanning electron microscopy and transmission electron microscopy have shown that ZnO adhered to the surface of Cu2O. Due to the doping of Cu2O, the absorption range of the Cu2O/ZnO catalyst is shifted from the ultraviolet to the visible region due to diffuse reflection. X-ray photoelectron spectroscopy and photoluminescence spectra have confirmed that there is a substantial interaction between the two phases of the resultant catalyst. The degradation efficiency of Cu2O/ZnO on methyl orange solution is obviously enhanced compared to Cu2O and ZnO. The maximum degradation efficiency is 98%. The degradation efficiency is affected by the pH of the solution and initial concentration. After three rounds of recycling, the degradation rate is almost same. This shows a consistent performance of Cu2O/ZnO. The increase in catalytic ability is related to the lattice interaction caused by the doping of Cu2O.

Characteristics of Indium Zinc Oxide Thin Films Deposited by Radio Frequency Reactive Magnetron Sputtering for Solar Cells Application

2007 ◽  
Vol 124-126 ◽  
pp. 999-1002 ◽  
Author(s):  
Han Na Cho ◽  
Jang Woo Lee ◽  
Su Ryun Min ◽  
Chee Won Chung
Keyword(s):  
Thin Films ◽  
Zinc Oxide ◽  
Magnetron Sputtering ◽  
Radio Frequency ◽  
Visible Region ◽  
Film Surface ◽  
Optical Transmittance ◽  
Reactive Magnetron Sputtering ◽  
Reactive Magnetron ◽  
Indium Zinc Oxide

Indium zinc oxide (IZO) thin films were deposited on a glass substrate by radio frequency (rf) reactive magnetron sputtering method. As the rf power increased, the deposition rate and resistivity increased while the optical transmittance decreased owing to the increase of grain size. With increasing gas pressure, the resistivity increased and the transmittance decreased. Atomic force microscopy and scanning electron microscopy were employed to observe the film surface. The IZO films displayed a resistivity of 3.8 × 10-4 Ω cm and a transmittance of about 90% in visible region.

scholarly journals Fabrication of a Cu2O-Au-TiO2 Heterostructure with Improved Photocatalytic Performance for the Abatement of Hazardous Toluene and α-Pinene Vapors

Catalysts ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1434
Author(s):  
Joon Yeob Lee ◽  
Jeong-Hak Choi
Keyword(s):  
Photoelectron Spectroscopy ◽  
Photocatalytic Oxidation ◽  
Separation Efficiency ◽  
Diffuse Reflectance Spectrum ◽  
Visible Region ◽  
Pure Tio2 ◽  
Great Promise ◽  
Light Sources ◽  
Electron Hole ◽  
X Ray

In the current research, a Cu2O-Au-TiO2 heterostructure was fabricated via a step-wise photodeposition route to determine its possible application in the photocatalytic oxidation of hazardous vapors. The results of electron microscopy and X-ray photoelectron spectroscopy confirm the successful fabrication of the Cu2O-Au-TiO2 heterostructure. Strong absorption in the visible region, along with a slight red-shift in the absorption edge, was observed in the UV–vis diffuse reflectance spectrum of Cu2O-Au-TiO2 composite, which implies that the composite can generate a greater number of photoexcited charges necessary for photocatalytic reaction. Toluene and α-pinene, as common gas contaminants in the indoor atmosphere, were employed to assess the photooxidation efficiency of the Cu2O-Au-TiO2 composite. Importantly, photocatalytic activity results indicate that the Cu2O-Au-TiO2 composite showed excellent photodegradation performance compared to pure TiO2 and Cu2O-TiO2 and Au-TiO2, where photocatalytic efficiency was approximately 92.9% and 99.9% for toluene and α-pinene, respectively, under standard daylight illumination. The increased light-harvesting capacity and boosted separation efficiency of electron-hole pairs were mainly accountable for improved degradation performance of the Cu2O-Au-TiO2 composite. In addition, the degradation efficiencies for toluene and α-pinene by the Cu2O-Au-TiO2 composite were also examined under three different light sources: 0.32 W white, blue and violet LEDs. The findings of this work suggested a great promise of effective photooxidation of gas pollutants by the Cu2O-Au-TiO2 composite.

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