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Preparation and Study of Spectral Analyses and

Optical Properties of Nanopole Sensitive to Light of

Hydrogen Fuel Production

Haleemah J. Mohammed, Kassim M. Sahan, Roaa Sh. Mahmood, and Noor M. Jalal

Renewable Energies Directorate

Ministry of Science and Technology, MOST

Baghdad, Iraq

Abstract - In this paper, nano NiO thin films were

prepared onto glass substrates by ultrasonic spraying material. A second harmonic Nd: YAG laser (532 nm, 25 mW) has been used for annealing this film. X-ray diffraction (XRD) results indicate that prepared films are polycrystalline structure with (111, 200) plane reflections, it was found that the prepared films have high transmittance in the visible region and optical band gap was 4 eV. The surface morphology of the nano NiO as measured by atomic force microscope (AFM) showed that the surface roughness.

Keywords - spectral characteristics and optical; oxide nickel films; X-ray diffraction; atomic force microscope.

I. INTRODUCTION

Hydrogen may play an important role as an energy carrier of the future [1]. Hydrogen can be produced from its primary materials review of the available literature on issues relevant to hydrogen production reveals that water electrolysis would be the easiest option and the only one currently practical [2,3]. There are several options for producing hydrogen from renewable sources [4]. Solar and wind energy are two technologies that are commercially available to provide electricity for electrolysis. The cost of electricity is a significant portion of the cost of making hydrogen with electrolysis. The production of hydrogen through electrolysis from solar and wind energy is not currently cost-competitive because of high electricity cost (relative to grid electricity at today's bulk electricity prices) and because electrolyzes require further development [5, 6].

The complex new electrolysis materials which have been developed are a step towards lowering the cost of hydrogen as a clean, renewable energy option which does not involve fossil-fuel combustion. Techniques for fabricating high performance electrodes could dramatically improve the economics of producing hydrogen from solar power through a compact PEM electrolyzer. By using nanotechnology, nanotechnology is generating a lot of attention these days and building great expectations [7]. The researchers have developed novel anodes and cathodes which are highly conductive and durable. They could offer voltage efficiencies greater than 90% and an operating life exceeding 40,000 hours a superior performance to electrodes currently used in comparable commercial electrolyzes [8].

Synthesis and characterization of nano crystalline materials have recently gained much attention due to their unique properties. Nickel oxide (NiO) is a metal oxide semiconductor that has a wide range of technological applications [9]. Transition metal oxides like nickel oxides have found wide application such as: transparent electrode, efficient control of energy inflow-outflow of buildings or automobiles and aerospace, smart window, solar thermal absorber, electrodes for batteries, large scale optical switching glazing chemical sensors, electrochromic device [10]. NiO films have been prepared by various methods such as RF magnetron sputtering, chemical bath deposition, sol-gel method and pulsed laser deposition [11].

II. EXPERIMENTAL DETAIL

A. Preparation of Nanopole Sensitive to Light

Test preparation technique appropriate depends on several factors including the types of raw materials, the final specifications of the membrane, the type of rule, and application areas. The sensitive electrode can be prepared as the follows:

Create the cleaned glass rules to get rid of outstanding impurities because the presence of these impurities effects on the properties of the membranes record. The cleaning process includes washing glass bases with dilute hydrochloric acid and then leaving this glassware in ethanol for 8 minutes wash thoroughly with distilled water and dried. prepare a thin layer of nickel oxide and added the dichloride tin water SnCl2.2H2O the ratio doping 5%, then dissolve in (15 ml) acetic acid then added (30 ml) of distilled water, after completion of glass create rules and complete the process of preparing solutions, we then conduct the spraying process using a spray device working by ultrasound, as shown in Fig. 1, then annealing by laser technique.

A beam is used from second harmonic Nd: YAG laser (532 nm, 25 mW) Use the power gauge type (Gentex) to measure the energy emerging from the laser system, and thus were calibrated laser system to determine the laser energy used.

978-1-4799-0712-0/13/$31.00 ©2013 IEEE

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Fig. 1. Shown the rules glass after spraying.

B. Preparation of Samples for Tests

Attended several concentrations of standard nano NiO for the purpose of the survey spectroscopy UV-Vis spectrophotometer device to identify the appropriate wavelengths and the calibration curve and attended the standard solutions of (1-100 ppm) at lengths suggestive of all samples. Is used a second harmonic Nd: YAG laser beam (532 nm, 25 mW) is incident normal to the liquid surface after passing through the bottom of the sample cell. An aperture (1 mm diameter) is located at the strongest part of the transmitted light, and the selected light is detected by a photodiode detector. Data were collected by an A-D converter after amplification. The sampling frequency was 10 kHz (t=0.1 ms). Detection and spectral analysis of this optical radiation using a sensitive spectrograph can be used to yield information on the elemental composition of the sample. The optical transmittance and absorbance of this film has been measured using device Spectrophotometer (Shimadzu - Spectrophotometer). The energy band gap of the nickel oxide nanopole can be measured through Eq. (1)

The absorption coefficient (α) and optical energy gap (Eg) are related by [12]:

αhν = A(hν - Eg) 1/2

(1)

Where A is a constant depending on transmission probability, h is Plank’s constant, ν is the frequency of the incident photon, Eg is the energy gap of the material.

The atomic force microscopy AFM (NanoScope (R) III model Veeco Metrology Group, USA) was measured the surface roughness of this film (nanopole). X-ray diffraction device (XRD-6000 Shimadzu Japan) was used for the purpose of measuring this of crystalline structures formed in the samples. We used the Barak law to calculate the distance (d) between the atomic levels [13]:

nλ = 2d sin (2)

Where n is diffraction rank equal to 1, is angle of diffraction, λ is wavelength of X-rays.

Stages were identified by comparing the values of the spaces formed between the levels after X-ray diffraction using standard tables (ASTM).

III. RESULTS AND DISUSSION

A. Spectral Analysis

We prepared standard solutions of (1-100 ppm) for all wavelengths that used in prepare material. Optical VU-Vis spectrometer was also enabled to identify wavelengths appropriate to set material for calibration curve of the

material. Depending on λmax of the calibration curve that used in clarifying linear amount and obtaining different absorbency change focus as in the Fig. 2 and Fig. 3 show the relationship between wavelength and absorbance of a substance prepared after laser treatment. When a laser beam is directed on the sample, spectral analysis by laser technology is an advanced and important method that can analyze solids, liquid and gas and get results very quickly, without causing any significant damage to the sample. It can also operate at a greater distance relatively to other technologies that require bringing the sample to the laboratory for analysis [14].

Fig. 2. The relationship between the wavelength and absorbance sample prepared.

Fig. 3. The relationship between wavelength and absorbance of a substance prepared after laser treatment.

Depending on the wavelength different concentrations of standard material and the extent (1-100 μg/ml) were obtained with different absorbance change concentration, as show in Fig. 4 and Fig. 5 that obtained for curved calibration of standard material to determine the value (r) of correlation coefficient and is equal to 0.9987 UV-Vis spectrophotometer. The laser techniques was the value of (r) correlation coefficient equal to 0.9999 and which is clear to us the amount of written as well as the selected standard deviation (SD) and standard deviation percentage (RSD) and the results were also evaluated in Table I.

Fig. 4. Calibration curve before the laser treatment.

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Fig. 5. Calibration curve after the laser treatment.

TABLE 1 STANDERD DEVIATION OF THE CENTENNIAL OF THE STANDARD SUBSTRANCE

Substance Derived of

concentration ppm

Calculated of concentration

ppm

Rec. %

R.S.D

Treatment after laser technology

50 49 99 4.95

Treatment before laser technology

50 48 98 4.90

B. Results of Optical Properties

The material properties have an active role in surface treatment by laser. These properties Includes impact resistance, reflectivity, absorbance and surface roughness. Thermal properties related to the heat flow inside the material, especially thermal conductivity and heat capacity and latent heat of fusion [15]. The conductivity of material will increase as treated will laser beam as shown in Fig. 6 and Fig.7 before and after treatment.

Fig. 6. Shows nanopole sensitive after laser treatment.

Fig. 7. Shows nanopole sensitive before the laser treatment.

Transitions, which respectively can be defined as the ratio between the optical powers carried from the surface to the energy falling on the surface take zero value in the case of dark objects [16]. Fig. 8 Shown the permeable to nanopole as a function of wavelength incident. The transmittance increase rapidly and later the greater value in the wavelength range (400-1100 nm).

Fig. 8. The spectrum of transitions.

Fig. 9 shows the amount of change in the absorption coefficient of the nanopole in the wavelength range of (350–1100 nm). It is used from this figure decrease in the absorption coefficient with increasing wavelength. So that to obtain laser effect in the material there must be absorption of the laser beam. As this absorption is very important to interaction process with laser material. This absorption process is a major source of energy within the material. Fig. 10a and Fig. 10b illustrate the laboratory work laser technology to measure transmittance and absorbance.

Fig. 9. The amount of change in the absorption coefficient of the nanopole with the wavelength.

Fig. 10a. Laboratory work shows laser technology to measure transmittance and absorbance.

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Fig. 10b. Laboratory work shows laser technology to measure absorbance.

C. Results of The Energy Gap

The measured energy gap if nano NiO thin film is equal to 4 eV. The testing technique depends on many factors including the types of specialist raw materials, as well as the spraying Thermo chemical factors affected on the rate of precipitation concerning of the process of spraying. In contrast in the crystal structure of the membrane electrode which leads to change in the energy gap as shown in Fig. 11.

Fig. 11 The energy band gap of the nanopole.

D. Results of an Atomic Force Microscope

The rapid annealing has a positive clear effect on prepared thin film oxide, as shown in Fig. 12. That if the temperature of annealing increased, the homogeneity of thin film treated by laser increased too and the distribution of granules is homogonous as in Fig. 13 it was found that the root mean square (rms) of the surface roughness of the NiO thin film, and will be less volume of small blocks of atoms volatile matter precipitin Pole will be more increased annealing temperature. As it is the best case when laser treatment due to increased regularly doping pole and organize the distribution of the granules.

Fig. 12. Atomic force microscope examination before the laser treatment.

Fig. 13. Atomic force microscope examination after the laser treatment.

E. Results of X-ray Diffraction

An X-rays spectrum of deposited films (nanopole) after the treatment by Nd - YAG laser is shown in Fig. 14. It is found that the prepared films are polycrystalline structure with (111, 200) plan refraction and this is consistent with research published previously, after comparing with standard tables (ASTM).

Fig. 14. X-ray diffraction analysis.

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After studying the optical and spectral analysis and achieving the special tests of the nanopole, we used this electrode as cathode of the electrolysis cell; while the anode electrode was made of stainless steel. We notice from experiments that H2 will be released on the nanopole during a short period of time. Did not use any electrical source, but use solar source as the Figs. 15a and 15b, we notice hydrogen production on nanopole.

Fig. 15a. Laboratory work shows hydrogen production on nanopole.

Fig. 15b. Laboratory work shows hydrogen production on nanopole after a short period of time.

IV. CONCLUSIONS

The study of structure optical and spectral characteristics has great importance, which gives extensive information about the nature of the materials and their properties. These nanoscale materials have many applications including nanopole Which can be used in the process of electrolysis of water to produce clean hydrogen fuel without emitting chlorine gas.

REFERERNCE

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[4] M. Momirlan and T.N. Veziroglu,”Current status of hydrogen energy'' Renewable and Sustainable Energy Reviews. 6, 2002, pp. 141–179.

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[7] Elena Serrano, Guillermo Rus, Javier Garcı Martınez, Nanotechnology for sustainable energy University of Alicante, Carretera Alicante-San Vicente, E-03690 Alicante, Spain Dpt. Structural Mechanics, University of Granada, Polite´cnico de Fuentenueva, 18071 Granada, Spain Renewable and Sustainable Energy, 2009, Reviews 13, 2373–2384 .

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