KMITL

Permanent URI for this communityhttps://dspace.kmitl.ac.th/handle/123456789/1

Browse

Search Results

Now showing 1 - 6 of 6

Some of the metrics are blocked by your
consent settings
Effect of Ultrasonic Irradiation Time on Physical Properties and Photocatalytic Performance of BiVO4 Nanoparticles Prepared via Sonochemical Process
(2021-01-01)
Kansaard, Thanaphon
;
Bangbai, Chatpong
;
Jayasankar, C. K.
;
Pecharapa, Wisanu
Currently, photocatalyst materials have gained considerable attraction because of very rich economic performance of decomposition of highly toxic organic compound to lower toxic composition. The effort of this work was paid to study the effect of sonochemical ultrasonic irradiation time on the relevant properties of visible-light-driven bismuth vanadate (BiVO<inf>4</inf>) photocatalyst without any further thermal treatment process. The chemical bonding of BiVO<inf>4</inf> nanopowder was investigated by Fourier transform infrared (FTIR) and Raman spectrometer technique. Meanwhile their structure was characterized by X-ray diffraction technique (XRD). Field emission scanning electron microscope (FE-SEM) was used to observe particle morphology and chemical compositions was investigated by Energy-dispersive X-ray spectroscopy (EDX). Photocatalytic performance of BiVO<inf>4</inf> nanopowder was studied by decomposition of organic dye as organic pollutant model using visible light to excite photocatalyst materials. It was found that sonochemical irradiation time supplied during chemical process can effectively expedite the formation of BiVO<inf>4</inf> nanoparticle. The optimized condition to obtain the product with enhanced photocatalytic performance of 60% decomposition is achieved as the sample was prepared at 40 min ultrasonic irradiation.
Some of the metrics are blocked by your
consent settings
Synthesis and characterization of F doped ZnO nanopowders by chemical routes of co-precipitation and sonochemical process
(2018-09-05)
Bangbai, Chatpong
;
Thongpradith, Titarat
;
Pecharapa, Wisanu
;
Mekprasart, Wanichaya
Zinc oxide (ZnO) is an n-type semiconductor material at room temperature which a good absorber in UV region and used in many applications, such as photocatalyst and gas sensor. In this work, ZnO nanopowders were synthesized by chemical routes; co-precipitation and sonochemical method. To improve ZnO nanopowders in optical and electrical properties, fluorine (F) was doped with varied concentration from 0-9 mol%. Zinc nitrate and ammonium fluoride were used as precursor material in both processes. Ammonia solution was dropped in the solution relating to white colloidal solution. Crystalline structure in hexagonal structure of F doped ZnO was identified by X-ray diffraction (XRD). Morphology and chemical element in F doped ZnO were monitored by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX). For optical and electrical properties, F doped ZnO particles were analyzed by UV-Visible spectroscopy and four point probe method, respectively. XRD pattern of ZnO structure after F doping with high crystallinity was similar to pure ZnO and obtained by both processes after annealing treatment beyond specific temperature. F doped ZnO morphologies were formed in rod-like structure by co-precipitation method. The increase of rod length was related by adding F doping concentration in ZnO matrix. Meanwhile, F doped ZnO products were formed in spherical structure with same crystallite size and particle size by sonochemical method due to the effect of ultrasound energy in the system. The improvement of optical and electrical properties in F doped ZnO was drastically obtained by co-precipitation method. The decreases of optical bandgap and electrical resistivity by F doped ZnO with co-precipitation method was occurred at 1 and 5 mol% F dopant. The influence of fluorine on ZnO structure was resulted in the defect level in band diagram and rod-like relating to narrow bandgap energy and good conductivity in ZnO.
Some of the metrics are blocked by your
consent settings
Effect of hexamethylenetetramine and temperature on morphological and structural properties of hydrothermally grown ZnSn(OH)6 structure
(2017-01-01)
Bangbai, Chatpong
;
Kamsong, Jatuporn
;
Nakhanivej, Puritat
;
Mekprasart, Wanichaya
;
Pecharapa, Wisanu
In this work, the effort has been conducted on the one-step hydrothermal synthesis of Zinc hydroxidestannate ZnSn(OH)<inf>6</inf>. Zinc chloride (ZnCl<inf>2</inf>) and tin(IV) chloride pentrahydrate (SnCl<inf>4</inf>•5H<inf>2</inf>O) were utilized as starting precursors of Zn and Sn and hexamethylenetetramine (HMT) was acted as pH buffer and OH<sup>-</sup> donator in the process. Effect of HMT during hydrothermal process on morphological and physical properties of the compound was investigated. The properties of hydrothermally grown ZnSn(OH)<inf>6</inf> were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). It is revealed that HMT plays a key role on the formation of well-defined structure of ZnSn(OH)<inf>6</inf> in form of polyhedron structures with different size depending on hydrothermal temperature. Meanwhile the irregular shape of the as-synthesized product was obtained as the growth was conducted without the assistance of HMT. Further details of results and deep discussion on its role during the growth also represented.
Some of the metrics are blocked by your
consent settings
Effect of Al and N doping on structural and optical properties of sol-gel derived ZnO thin films
(2013-02-01)
Bangbai, Chatpong
;
Chongsri, Krisana
;
Pecharapa, Wisanu
;
Techitdheera, Wicharn
In this work, the preparation of ZnO, N-doped ZnO (NZO), Al-doped ZnO (AZO) and Al, N-doped ZnO (ANZO) thin films by the sol-gel spin-coating method is reported. The structural properties and surface morphologies of films were characterized by X-ray diffraction (XRD) and field emission scanning electron microscope (FE-SEM). The optical properties of the films were interpreted from their transmission spectra using UV-VIS spectrophotometer. The XRD and SEM results disclosed that the crystallization quality and grain size of as-prepared films were highly influenced by N and Al doping. UV-VIS spectrophotometer results indicated that Al and N additives could significantly enhance the optical transparency and induce the blue-shift in optical bandgap of ZnO films.
Some of the metrics are blocked by your
consent settings
Characterization and photoresponse propreties of sn-doped ZnO thin films
(2013-01-01)
Chongsri, Krisana
;
Bangbai, Chatpong
;
Techitdheera, Wicharn
;
Pecharapa, Wisanu
Sn-doped ZnO (SZO) thin films were prepared by sol-gel spin-coating method based on zinc acetate dihydrate (CH<inf>3</inf>COO)<inf>2</inf> Zn·2H<inf>2</inf>O, Tin (IV) chloride pentahydrate (SnCl <inf>4</inf>5H<inf>2</inf>O), 2-methoxyethanol (C<inf>3</inf>H<inf>8</inf>O <inf>2</inf>) and diethanolamine ((HOCH<inf>2</inf>CH<inf>2</inf>) <inf>2</inf>NH, DEA.The solution was prepared with various Sn doping content in ZnO assigned at 2%, 4%, 6%, 8% and 10%. All films were spin-coated on borosilicate substrates and annealed temperature at 550°C for 4 h in air. The structural properties of the films were characterized by XRD and SEM and the corresponding results indicated the crystalline structure and surface morphology of the films, respectively. UV-VIS transmission spectra was used to determine optical properties of asprepared. The increasing Sn doping content into ZnO films results to the enhancement in transparency of the films and the observable alternation in their grain size. The photoilluminated current linearly increases with increasing bias voltage indicating the good Ohmic contact of the device. The photoresponse of the device has significant improvement with increasing Sn doping content. © 2013 The Authors.
Some of the metrics are blocked by your
consent settings
Effect of Al and N doping on structural and optical properties of sol-gel derived ZnO thin films
(2012-03-15)
Bangbai, Chatpong
;
Chongsri, Krisana
;
Pecharapa, Wisanu
;
Techidheera, Wicharn
In this work, ZnO, N-doped ZnO(NZO), Al-doped ZnO(AZO) and Al, N-doped ZnO(ANZO) thin films were prepared by the sol-gel spin-coating method based on zinc acetate dihydrate(CH <inf>3</inf>COO) <inf>2</inf>Zn2H <inf>2</inf>O, Aluminium acetate (C <inf>4</inf>H <inf>7</inf>AlO <inf>5</inf>), Ammonium acetate(CH <inf>3</inf>COONH <inf>4</inf>), absolute ethanol (C <inf>2</inf>H <inf>5</inf>OH) and diethanolamine ((HOCH <inf>2</inf>CH <inf>2</inf>) <inf>2</inf>NH, DEA). All films were spin-coated on borosilicate substate for several coating repetition followed by annealing process at 550 C for 4 hr in air. The structural properties and surface morphologies of films were characterized by X-ray diffraction (XRD) and Field Emission Scanning Electron Microscope (FE-SEM). The optical properties of the films were interpreted from their transmission spectra using UV-VIS spectrophotometer. © 2012 IEEE.

KMITL

Browse

Filters

Settings

Sort By

Results per page

Search Results