Papers by Thapanee Sarakonsri
Advanced Functional Materials, 2018
Crystals, 2021
This work aimed to design a facile preparation of sandwich-liked Ge nanoparticles/nitrogen-doped ... more This work aimed to design a facile preparation of sandwich-liked Ge nanoparticles/nitrogen-doped reduced graphene oxide (Ge/NrGO) nanocomposites used as anode in lithium-ion batteries through the chemical solution route. The advanced electron microscopy, STEM-HAADF and STEM-EDS mapping, evidenced that the individual Ge particles with sizes ranging from 5 to 20 nm were distributed and wrapped as sandwiches within the multi-layered NrGO sheets, which were mainly composed of the pyridinic-N form (4.8%wt.). The battery performances of the 20Ge/NrGO nanocomposite anode exhibit a high reversible capacity (700 mAh g−1) and retained its outstanding stability during long-term cycling. The internal resistance (28.0 Ω) was also decreased after cycling, according to EIS measurement. The sandwiched structure of Ge-based nanocomposite with the interconnected NrGO layers discussed in this article possessed the high-performance LIBs with great potential application in energy storage technologies.
Journal of Materials Science: Materials in Electronics, 2022
The new nanocomposites of silicon dioxide/reduced graphene oxide (SiO2/rGO) and silicon dioxide/n... more The new nanocomposites of silicon dioxide/reduced graphene oxide (SiO2/rGO) and silicon dioxide/nitrogen-doped reduced graphene oxide (SiO2/NrGO) were synthesized by a simple and inexpensive technique. An agricultural waste such as rice husk was chosen as the low-cost biomass resource in order to produce SiO2 nanoparticles. Phase characterization indicated the coexistence of graphene and amorphous SiO2 in both SiO2/rGO and SiO2/NrGO nanocomposites, suggesting the successful incorporation of SiO2 into graphene sheets. Both composites showed the good distribution of SiO2 nanoparticles on graphene sheets which could benefit for their electrochemical characteristics. The obtained SiO2/rGO and SiO2/NrGO nanocomposites possessed high capacity and superior cycle performance. This work demonstrated that the effective preparation technique can be used to produce the new nanocomposites with high performance and cost effective for LIBs. The techniques used in this work were both easy and environmentally friendly.
Crystals, 2022
Popped rice carbons (PC) were derived from popped rice by using a facile and low-cost technique. ... more Popped rice carbons (PC) were derived from popped rice by using a facile and low-cost technique. PC was then activated by different kinds of activating agents, such as potassium hydroxide (KOH), zinc chloride (ZnCl2), iron (III) chloride (FeCl3), and magnesium (Mg), in order to increase the number of pores and specific surface area. The phase formation of porous activated carbon (PAC) products after the activation process suggested that all samples showed mainly graphitic, amorphous carbon, or nanocrystalline graphitic carbon. Microstructure observations showed the interconnected macropore in all samples. Moreover, additional micropores and mesopores were also found in all PAC products. The PAC, which was activated by KOH (PAC-KOH), possessed the largest surface area and pore volume. This contributed to excellent electrochemical performance, as evidenced by the highest capacity value (383 mAh g−1 for 150 cycles at a current density of 100 mA g−1). In addition, the preparation used i...
Solid State Phenomena, 2020
In this study, nitrogen-doped graphene (NrGO)/ titanium dioxide (B) (TiO2(B))/ silicon composites... more In this study, nitrogen-doped graphene (NrGO)/ titanium dioxide (B) (TiO2(B))/ silicon composites were synthesized by dispersion method. Weight ratios of NrGO:TiO2(B):Si were varied as 9:1:0, 8:2:0, 7:1:2 and 6:2:2. NrGO was prepared from graphite by the Modified Hummers method, followed by heat treatment under nitrogen atmosphere and N-added by annealing with melamine. TiO2(B) was prepared by hydrothermal method and its phase was confirmed by X-Ray powder diffraction pattern (XRD), transmission electron microscopy (TEM) and electron diffraction pattern. Silicon was synthesized from bamboo leaves by combustion followed by magnesiothermic reduction process. The results from XRD could confirm components of the composites and the unchanged phase of TiO2(B). From scanning electron microscopy (SEM) images of the composites, together with energy dispersive spectroscopy (EDS) data, silicon particles were distributed on the surface of NrGO, and TiO2(B) nanorods which are between 0.5-5 µm in...
Solid State Phenomena, 2020
Si and Mg are good candidates for anode lithium-ion batteries because Si and Mg have high theoret... more Si and Mg are good candidates for anode lithium-ion batteries because Si and Mg have high theoretical capacity of 4200 mAh g-1 and 994 mAh g-1, respectively. However, these elements generate high-volume expansion during the charge-discharge process, which can cause the electrode to crack after being used for a few cycles. To solve this problem, the active materials are prepared in a nanosize and composited with a 2D-sheet of nitrogen-doped graphene, as the high mechanical stability and flexibility of nitrogen-doped graphene can support the volume expansion. Preparation of Si-Mg and nitrogen-doped graphene includes two steps. First, the reduction of Mg2+ ions with NaBH4 in ethylene glycol solution and reflux at 350 - 400 °C for 3 hr and Si nanoparticles, which were prepared by magnesiothermic reduction, was conducted. Second, Si and Mg nanoparticles and nitrogen-doped graphene were mixed in ethylene glycol solution and then collected by centrifugation. The obtained Si-Mg nanocomposit...
Solid State Phenomena, 2020
Synthesis routes of CoSb3 need a long reaction time, especially at high temperature and-/or high ... more Synthesis routes of CoSb3 need a long reaction time, especially at high temperature and-/or high pressure. Although the modified polyol process assisted with microwave radiation can be used to solve these problems, it used the excess amount of Sb ion. Therefore, this study aimed to solve this drawback by retarding the rate of reduction. The different microwave times (0, 1, and 3 min) were investigated to find out the shortest heating duration for preparing CoSb3 nanoparticles. Te-doped and Sn-doped CoSb3 were synthesized to investigate the benefit of this synthesis method for increasing the solubility limit of Te and Sn in the CoSb3 structure. The phase and microstructure of the synthesized products were characterized by using x-ray diffraction (XRD), scanning electron microscope (SEM) and transmission electron microscope (TEM). The results showed that the high crystalline phase of CoSb3 (JCPDS: 78-0977) without any metallic impurity phases product was successfully synthesized in 3 ...
Solid State Phenomena, 2020
Platinum (Pt) is widely used as anode catalyst for direct ethanol fuel cell (DEFC) but toxic CO g... more Platinum (Pt) is widely used as anode catalyst for direct ethanol fuel cell (DEFC) but toxic CO gas was produced in the system. Pt bimetallic catalysts can increase the reaction rate, current density and reduce CO gas production. However, some bimetallic catalysts are still expensive and give the low reaction rate. Trimetallic catalysts on carbon supporter were represented instead due to their better catalytic activities, long life time of operation and higher current density. In this study, we synthesized trimetallic alloy on N-doped reduced graphene oxide (NrGO) catalysts using as DEFC anode. The percentage of metals composition in the synthesized catalysts was varied. NrGO was prepared by Modified Hummers Method, then reduced by annealing under Nitrogen gas atmosphere and N-added by annealing with melamine. The preparation method for trimetallic alloy catalysts on NrGO was NaBH4 reduction. The X-ray diffraction (XRD) patterns displayed their alloy phase of PtMRu (M = Au, Sn) whic...
Activated carbon cloths (ACCs) were used as a support for preparation of Au nanoparticles. Pretre... more Activated carbon cloths (ACCs) were used as a support for preparation of Au nanoparticles. Pretreatment of ACCs was performed by using oxidizing agent HNO3 in order to introduce surface oxygen complex. Au nanoparticles were prepared by impregnation of tetrachloroauric acid (HAuCl4) without reducing agents in deionized water and ethanol. It was found that the preparation in ethanol solution achieved uniformly dispersed Au nanoparticles with diameter 10-100 nm on the support surfaces. X-ray diffraction (XRD) was employed to verify structural characteristics of Au metal adsorption on oxidized ACC surfaces. Morphology and composition were carried out by Scanning electron microscopy (SEM) and Energy dispersive spectroscopy (EDS), respectively.
Crystals, 2021
SnS nanomaterials have a high initial capacity of 1000 mAh g−1; however, this cannot be retained ... more SnS nanomaterials have a high initial capacity of 1000 mAh g−1; however, this cannot be retained throughout electrochemical cycling. The present study provides insight into this capacity decay by examining the effect that Li intercalation has on SnS “nanoflowers” attached on carbon substrates’ such as artificial graphite. Scanning and transmission electron microscopy reveal that lithiation of such materials disrupts their initial morphology and produces free-standing Sn and SnS nanoparticles that dissolve in the electrolyte and disperse uniformly over the entire electrode surface. As a result, the SnS is rendered inactive after initial cycling and contributes to the formation of the solid electrolyte interface layer, resulting in continuous capacity decay during long term cycling. This is the first study that illustrates the morphological effects that the conversion mechanism has on SnS anodes. In order to fully utilize SnS materials, it is necessary to isolate them from the electro...
Sustainable Energy & Fuels, 2020
Novel anode materials for lithium-ion batteries, nanocomposites of Sn (or SnO2) and SiO2 with gra... more Novel anode materials for lithium-ion batteries, nanocomposites of Sn (or SnO2) and SiO2 with graphene-based sheets (GO, rGO and NrGO), were synthesized by a facile and low-cost technique. The capacity of all composites was relatively high as compared to traditional graphite.
RSC Advances, 2020
The TiO2-bronze/nitrogen-doped graphene nanocomposites have the potential for fast-charging and h... more The TiO2-bronze/nitrogen-doped graphene nanocomposites have the potential for fast-charging and have high stability, showing potential as an anode material in advanced power batteries for next-generation applications.
Solid State Phenomena, 2020
Nowadays, there is an increasing of the demanding in high energy density lithium-ion batteries (L... more Nowadays, there is an increasing of the demanding in high energy density lithium-ion batteries (LIBs) due to the growing of energy storage needs for electronic vehicles and portable devices. Silicon (Si) and Tin (Sn) are the promising anode materials for LIBs due to their high theoretical capacity of 4200 mAh/g and 994 mAh/g. Moreover, Si can be derived from rice husk which is the main agricultural product in Thailand. However, the using of Si and Sn encounters with the huge volume expansion during lithiation and delithiation process. To alleviate this problem, Nitrogen-doped graphene (NrGO), carbon supporter, is used as composite with these metals to buffer the volume change and increase the electrical conductivity of composites. This work aims to synthesis Si/NrGO and SiSn/NrGO nanocomposites and Si used in these composites is derived from rice husk. All products were characterized by X-rays diffraction (XRD), Scanning electron microscopy (SEM) and transmission electron microscopy...
Solid State Phenomena, 2018
Dye sensitized solar cells (DSSCs) consist of photoanodes (dye adsorbed porous semiconductor film... more Dye sensitized solar cells (DSSCs) consist of photoanodes (dye adsorbed porous semiconductor film), electrolytes and counter electrodes. Nanostructured materials play important parts in both the photoanodes and the counter electrodes, while dyes are there to absorb photons and generate electron-hole pairs and electrolytes are there to transfer electrons from the photoanodes to the counter electrodes. In this study, to enhance light absorption and minimize electron-hole recombination, Ag nanoparticles and MgO nanolayer were coated on TiO2, respectively. To enable a long lifetime, i.e. avoiding liquid electrolyte leakage, quasi-solid-state (QSS) DSSCs were fabricated. PtSn nanoparticles were prepared by a simple chemical reduction method on graphene oxide (GO) to compare with conventional Pt catalyst on FTO substrates as counter electrodes. An average efficiency of the QSS DSSCs with PtSn/GO co-catalysts was found to outperform that of the QSS DSSCs with conventional Pt catalyst. A mi...
Solid State Phenomena, 2018
Silicon-cobalt nanocomposites on NrGO, Si-Co/NrGO, were synthesized by the modified polyol method... more Silicon-cobalt nanocomposites on NrGO, Si-Co/NrGO, were synthesized by the modified polyol method. Rice husk was used as the silicon source. The composites were primarily characterized by x-ray diffraction, scanning electron microscopy, and transmission electron microscopy equipped with energy dispersive spectroscopy. The small-sized particles of the silicon-cobalt product were effectively distributed on the NrGO. Finally, these anode materials were tested in lithium-ion batteries by haft-coin cell assembly. Electrochemical properties were measured and the result showed an initial capacity of 975 mAh g-1. This material is expected to be used as a high-performance anode, suitable for the next generation of anode materials in lithium-ion batteries.
Materials Today: Proceedings, 2019
Binary and ternary alloys of PdNi, PdCo, PdCu and PdNiCo on Nitrogen-doped graphene (N-doped grap... more Binary and ternary alloys of PdNi, PdCo, PdCu and PdNiCo on Nitrogen-doped graphene (N-doped graphene) supporter, which prepared by modified Hummers method, were prepared via solution route using sodium borohydride (NaBH 4) as a reducing agent, microwave-assisted and polyol methods to improve the activity of oxygen reduction reaction (ORR) in direct ethanol fuel cells (DEFC). The X-ray diffraction (XRD) results confirm the formation of Pd alloy nanocatalyst phases. The scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images of as prepared catalysts show that alloy catalysts are well dispersed on N-doped graphene. Particle size measured from TEM micrographs are in the range of 4-11 nm. This provided large active surface area for ORR. The small particles of the ternary PdNiCo alloy catalysts on N-doped graphene prepared via NaBH 4 reduction method showed the highest power density of 224.6 mW/cm 2 .mol for fuel cells. Therefore, these PdNiCo on Ndoped graphene migh be good catalysts for use as next generation cathode materials in DEFC.
Research on Chemical Intermediates, 2016
A non-precious metal FeNi electrocatalyst (FeNi/NG) was prepared by a simple solution route calle... more A non-precious metal FeNi electrocatalyst (FeNi/NG) was prepared by a simple solution route called the polyol process for use as the oxygen reduction reaction (ORR) catalyst in polymer exchange membrane fuel cells. The nitrogen-doped graphene (NG) was synthesized from graphite oxide (GO) in a one-pot reactor via thermal annealing of GO-mixed melamine. The obtained NG presents high content of pyridinic-N and quaternary-N types with acceptable activity of ORR in acidic media by XPS and cyclic voltammetry techniques, respectively. The non-precious FeNi alloy nanoparticles (spherical-like nanoparticles mixed with hexagonal plate-like features) were successfully synthesized and well dispersed on the prepared NG by the polyol process confirmed by SEM-BSE and TEM analysis. The XRD and SAED results found FeNi and the carbon phase in the prepared catalysts. Finally, the CV technique shows that the peak potential of FeNi/NG is in the range of 0.12–0.34 V, which is close to that of the commercial Pt/C catalyst (0.35 V). To summarize, the obtained catalyst (FeNi/NG) revealed reliable electrocatalytic properties for ORR in a proton exchange membrane fuel cell cathode.
Microscopy and Microanalysis, 2016
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Papers by Thapanee Sarakonsri