Sriwong, Chaval
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Item type:Publication, Preparation, characterization and photocatalytic properties of rubber-TiO2-rGO composite sheets for dye decomposition in wastewater(2017-01-01); In this work, rubber-TiO<inf>2</inf>-rGO (RT-rGO) composite sheets were successfully prepared by a simple latex mixing-casting method using TiO<inf>2</inf> and natural rubber latex with different amounts of rGO loading. The prepared RT-rGO sheet samples were characterized by XRD, FT-IR, Raman, SEM and EDS techniques. The photocatalytic properties of the prepared RT-rGO sheets as catalyst were evaluated using methylene blue (MB) dye solution under UV light irradiation. The result indicated that all the composite sheets loaded with rGO had better photocatalytic activities than the sheet without rGO loading. RT-rGO6.2% sheet showed the highest removal efficiency of 93.3% which has the rate constant (kapp) as 98.2 times higher than the unloaded sheet. Furthermore, the efficiency of the RT-rGO sheet upon the repeated usage was also studied. The result indicated that the sheet could be easily used, recovered and reused many times with no need for the cleaning in between successive uses. Thus, the RT-rGO sheet appears to be an attractive-material for the wastewater treatment or the water purification industry. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Preparation, characterization, and supercapasitive properties of CoO-NiO microflowers incorporated with graphene oxide and reduced graphene oxide hybrid materials(2018-01-01); This research investigated the preparation, characterization and supercapacitive properties of cobalt oxide-nickel oxide (CoO-NiO) microflowers incorporated with graphene oxide (GO) and reduced graphene oxide (RGO) nanosheets. These hybrid materials were easily prepared through a direct mixing of CoO-NiO powder suspended in acidic solution with the appropriate amount of GO and RGO loading to make CoO-NiO/GO and CoO-NiO/RGO hybrid samples, respectively. Then, the obtained hybrid samples were characterized by X-ray powder diffraction (XRD), Fourier-transformed infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) techniques. The results demonstrated that the crystalline phases and functional groups of all hybrid samples are corresponding to pristine CoO-NiO and RGO. SEM results showed that the CoO-NiO microflowers were impregnated and well-combined with both GO and rGO nanosheets. Moreover, the supercapacitive behavior of pristine CoO-NiO and all hybrid samples were studied using cyclic voltammetry (CV) technique. The results revealed that all hybrid samples exhibited much higher the current density than those of the bare CoO-NiO. Thus, this research indicates that the supercapacitive properties of CoO-NiO incorporated with both GO and RGO hybrid materials are superior to the pure CoO-NiO microflowers. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Removal of methylene blue dye using metal-free g-C3N4 photocatalyst over natural sunlight irradiation(2020-01-01); This work presented the high activity of metal-free g-C<inf>3</inf>N<inf>4</inf> photocatalyst for methylene blue (MB) removing over natural sunlight irradiation. These g-C<inf>3</inf>N<inf>4</inf> photocatalysts materials were synthesized by a conventional thermal condensation method using melamine as a precursor under treated at the various annealing temperatures (450 °C, 500 °C, 550 °C, 600 °C and 650 °C). All assynthesized samples were characterized and confirmed by a several techniques, such as, X-ray diffraction (XRD), Fourier transformed infrared spectroscopy (FTIR), UV-vis diffuse reflectance spectrometer (DRS), scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDS), and Brunauer-Emmett-Teller (BET) specific surface area. XRD and FTIR results confirmed that the as-synthesized g-C<inf>3</inf>N<inf>4</inf> samples were completely synthesized at annealing temperature of 500 °C. SEM images showed the morphologies of the g-C<inf>3</inf>N<inf>4</inf> samples had more flake-like structures upon the increasing of annealing temperatures. WhileDRS results indicated that the absorption edges of as-synthesized g-C<inf>3</inf>N<inf>4</inf> samples were shifted to visible-light region, except the sample as-synthesized at 650 °C (g-C<inf>3</inf>N<inf>4</inf>-650 °C). Moreover, the photocatalytic properties of metalfree g-C<inf>3</inf>N<inf>4</inf> photocatalyst materials were evaluated by degrading of MB dye solution under natural sunlight irradiation for 100 min. The results revealed that the highest photocatalytic activity was exhibited by the sample synthesized at 600 °C, which the apparent rate constant (kapp.) was 0.0291min<sup>-1</sup>. The orders of activities as:g-C<inf>3</inf>N<inf>4</inf>-600°C > g-C<inf>3</inf>N<inf>4</inf>-650 °C > g-C<inf>3</inf>N<inf>4</inf>-550 °C > g-C<inf>3</inf>N<inf>4</inf>-500°C > g-C<inf>3</inf>N<inf>4</inf>-450°C. Hence, the metal-free g-C<inf>3</inf>N<inf>4</inf> photocatalyst appears to be an attractivematerial for water or wastewater purification applications over activated by sunlight irradiation. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Effect of synthesized Ag nanoparticles by using the different amounts of polyvinylpyrrolidone for Ag-natural rubber hybrid sheets and their antibacterial properties(2017-01-01); Ag-natural rubber (Ag-NR) hybrid sheets were successfully prepared with a very simple and low cost method. In this method, silver nanoparticles (AgNPs) were firstly synthesized by a rapid and green microwave-assisted using polyvinylpyrroridone (PVP) media. The effect of PVP weight ratios towards the size of AgNPs was also investigated. Then, Ag-NR hybrid sheet samples were prepared by latex mixing-casting method using concentrated natural rubber (NR) latex with the synthesized AgNPs colloids. The characteristic absorption, particles sizes and shapes of the obtained AgNPs were examined through UV-vis, TEM and SAED. Also, the prepared Ag-NR sheet samples were characterized using XRD, FT-IR, SEM and EDS techniques. It was found that the particles sizes of all the synthesized AgNPs had spherical-like shape, and the mean sizes were increased from 29.7 to 90.4 nm upon increasing PVP contents. EDS results showed the AgNPs were well-dispersed and impregnated into the rubber matrix. Moreover, the antibacterial properties of the prepared Ag-NR sheets were tested by agar disk-diffusion method with Gram-positive and Gramnegative bacteria as Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli), respectively. The results showed that the hybrid sheets exhibited excellent antibacterial properties against these bacteria, in which the zones of inhibition were also dependent on the synthesized AgNPs by utilizing the different amounts of PVP. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Enhancing the supercapacitor performance of NiCo2O4 microflowers by reduced graphene oxide nano-sheets(2021-01-28); ; This work presented the preparation and supercapacitor performance of a spinel nickel-cobalt oxide (NiCo2O4) microflowers mixed with nano-sized reduced graphene oxide (rGO) sheets. The hybrid material (NiCo2O4/rGO), pure NiCo2O4 and nano-sized rGO samples were characterized and confirmed by several techniques, such as XRD, SEM and EDS. The supercapacitive properties of all prepared samples were also studied using an electrochemical measurement technique (CV and GCD). The results revealed that the NiCo2O4/rGO (484.1 F.g<sup>-1</sup>) hybrid electrode exhibited much higher specific capacitance than those of pristine NiCo2O4 (358.3 F.g<sup>-1</sup>) and nano-sized rGO (113.8 F.g<sup>-1</sup>) electrodes, respectively. Hence, this work indicates that the supercapacitor performance of NiCo2O4 mixed rGO hybrid materials is more superior to the pure NiCo2O4 microflowers and nano-sized rGO sheets. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, The electrochemical measurements investigation of NiCo2O4for electrode materials of energy storage devices by using digital holography technique(2021-01-01); The electrochemical properties of NiCo2O4for using as electrode materials for the potential applications have been investigated by electrochemical measurement which composed of cyclic voltammetry (CV) and galvanostatic chargedischarge (GCD). These processes are generating the ion exchange between the electrode and electrolyte, wherein induce the surface change of the interface. Especially, since in the cycle ability measurement using the potentiostat needed to repeat the cycle into the electrode for many times, the effective of the electrode is reduced. In this research, digital holographic technique was used to investigate the different properties of interface of the NiCo2O4 electrode while operating under the various electrochemical techniques. In our DH recording, the surface change of the electrode was expose at the difference potential scan rate at 1, 5, 10, 50, 100 and 200 mV/s of CV, and the difference current densities at 1, 2, 3, 5, 10 and 20 A/g of GCD and vary times of cycle ability test every 50 cycle times to 1000 cycles. In the end the reconstructed DH images of the electrode have been used to analyze the results from electrochemical measurement. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, AC/TiO2/rubber composite sheet catalysts; fabrication, characterization and photocatalytic activities(2015-11-04); Tejangkura, WorapolThe AC/TiO<inf>2</inf>/Rubber (ACTR) composite sheets weresuccessfully fabricated by a simply mixing of fixed TiO<inf>2</inf> suspension and natural rubber latex (60% HA) contents withthe varyingamounts of activated carbon (AC) suspension, followed by stirring,pouring into apetri dish mold, drying at room temperature (RT),after that taking out from a mold, reversing and drying again at RT. Then, the as-fabricated ACTR composite sheets were characterized by X-ray diffractometer (XRD), attenuated total reflectionFourier transform infrared spectroscopy (ATR-FTIR), energy dispersive X-ray spectroscopy (EDS) and scanning electron microscopy (SEM)techniques.The photocatalytic efficiencies of allACTR composite sheet sampleswere evaluated by photodegrading of methylene blue (MB) dye solution under UV light irradiation.The results showed that the photocatalytic activity of ACTR sheet with10.0wt%AC loadinghas the highest efficiency for the photodegradation of MB dye than the other sheets. This is due to the fact that it is relatively with the synergistic effect of well-combined titanium dioxide catalyst and activated carbon adsorbent. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Preparation and photocatalytic activities of tio2-rgo nanocomposite catalysts for mb dye degradation over sunlight irradiation(2018-01-01); ; - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Investigation of the influences of reaction temperature and time on the chemical reduction of graphene oxide by conventional method using Vitamin C as a reducing agent(2017-01-01); ; Kongtaweelert, SamartThe aim of this work is to investigate the synthesis of reduced graphene oxide (rGO) aqueous suspension by a conventional heating method using vitamin C as a reducing agent. The influences of reaction temperatures (70, 90 and 100 °C) and heating times (30, 45 and 60 min) on the chemical reduction of graphene oxide (GO) were studied. Then, the obtained rGO samples were characterized by FT-IR, Raman, UV-Vis, XRD and TEM techniques. The FT-IR and Raman results showed that the reduction degree of GO to rGO was increased with the rising of the reaction temperature and time. Moreover, the UV-Vis spectra demonstrated that the absorption band at around 230 nm (π-π*) of pristine GO had shift to the longer wavelength upon the chemical reduction, indicating that GO is reduced to rGO. The optimal condition of the chemical reduction of GO to achievable rGO was the temperature of 90 °C with the 45 min of heating time. This condition yielded the rGO black aqueous suspension with the high quality and stability. Thus, this method of synthesis has an advantage of the rGO dispersion which led to many potential applications.