Browsing by Author "Doong, Ruey-An"

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Boron, phosphorus co-doped one dimensional graphitic carbon nitride for photodegradation of diclofenac
(2019-03-31)
Ganganboina, Akhilesh Babu
;
Nguyen Thi Hien Luong
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Doong, Ruey-An
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環境工程研究所
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Institute of Environmental Engineering
Coconut shell derived activated biochar-manganese dioxide nanocomposites for high performance capacitive deionization
(2020-10-15)
Adorna Jr, Joemer
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Borines, Myra
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Van Dien Dang
;
Doong, Ruey-An
;
環境工程研究所
In this study, a Faradaic/electric double-layer hybrid capacitor using coconut shell derived activated biochar (AB) and MnO2 nanocomposite was fabricated for capacitive deionization (CDI) applications. Three different co-precipitation methods including indirect, direct, and acid-assisted grafting oxidation methods were explored to produce the AB-MnO2 nanocomposites. The alpha-MnO2 with an excellent ion intercalation ability was successfully deposited onto the AB, making the AB-MnO2 an excellent electrode material for CDI application in the presence of neutral Na2SO4 electrolytes. Notably, the AB-MnO2 nanocomposites prepared by indirect co-precipitation method (AB-MnO2-indirect) has shown a high specific surface area of 304 m(2) g(-1) with high mesopore volume ratio, high capacitance retention, good hydrophilicity and suitable pore texture to shorten the diffusion distance of ions. Cyclic voltammetric (CV) and electrochemical impedance spectroscopic (EIS) spectra showed that the AB-MnO2 yields a quasi-rectangular and symmetric CV plot, and specific capacitances of 410-523 F g(-1) at 5 mV s(-1) were observed. Moreover, the AB-MnO(2 )indirect exhibits excellent CDI performance at 1.2 V, and the specific electrosorption capacity of 33.9-68.4 mg g was obtained. Results of this study demonstrate that AB-MnO2 nanocomposites are superior electrochemical materials for CDI application, which can serve as alternative materials for designing an innovative electrochemical technology for water purification, desalination, and energy storage.
Development of molybdenum disulphide-graphene quantum dots nanostructure for electrochemical applications
(2016-08-20)
Bindumadhavan, Kartick
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Sahu, Rama
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Doong, Ruey-An
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環境工程研究所
;
Institute of Environmental Engineering
Dispersible nanocomposites of functionalized graphene oxide reinforced polyethylene for packaging application
(2016-08-20)
Toh, Guat Yee
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Ong, Hui
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Bindumadhavan, Kartick
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Doong, Ruey-An
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環境工程研究所
Effect of Lauric Acid on the Thermal and Mechanical Properties of Polyhydroxybutyrate (PHB)/Starch Composite Biofilms
(2020-06-19)
Adorna, Joemer A., Jr.
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Aleman, Camelle Kaye A.
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Gonzaga, Ian Lorenzo E.
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Pangasinan, Jamela N.
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Sisican, Kim Marie D.
Polyhydroxybutyrate (PHB) is a biopolymer of natural origin, one of the suitable alternatives for synthetic plastics. However, pure PHB has a high production cost, is relatively brittle, and has poor processability, hence its limited application. Combining PHB with biomass fillers and plasticizers can significantly improve the properties of the polymer, leading to its commercial usage. In this study, PHB was incorporated with starch (S) as a cheap biomass filler and lauric acid (LA) as a potential plasticizer. The PHB/S/LA composites were prepared using a modified solvent casting method with the incremental addition of LA. The PHB/S ratio was maintained at a ratio of 80/20 (w/w). Physicochemical characterization via EDS, XRD, and FTIR proved that the composite components have blended through nucleation and plasticization processes. The morphology of the PHB/S blends was found to be a heterogeneous matrix, with decreased inhomogeneity upon the addition of LA in the composite. Thermal characterization done by TGA and DSC showed that the thermal properties of PHB/S films improved with the addition of LA. Mechanical tests (UTM) proved that the elastic strain of the films also increased with the addition of LA, although the tensile strength decreased slightly compared to pure PHB/S. Overall, the results of this study provide baseline information on the improvement of PHB-based bioplastics.
Electrical and Dielectric Properties of Exfoliated Thermally Reduced Graphene Based Polyurethane Nanocomposites
(2017-12-01)
Bansala, Taruna
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Joshi, Mangala
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Mukhopadhyay, Samrat
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Doong, Ruey-An
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Chaudhary, Manchal
Thermally reduced graphene nanosheets (TRG) were prepared by using thermal exfoliation followed by annealing and then were served as fillers to well disperse in thermoplastic polyurethane (TPU) in a concentration range of 0.5-5.5 vol.%. The electrical conductivity, dielectric and mechanical properties of as-prepared TPU/TRG nanocomposite thin films were examined. The DC electrical conductivity was improved up to 3 x 1x10(-2) S m(-1) for the 5.5 vol.% TPU/TRG nanocomposite in comparison to 2 x 81x10(-11) S m(-1) for neat TPU matrix. Addition of TRG nanosheets enhanced the Young's modulus but reduced the strain-at-break and tensile strength of the nanocomposite films. The dielectric behavior including dielectric constant (epsilon) and tangent loss varied with the TRG loading in the nanocomposites. Results showed the increase in dielectric constant from 1 to 550 as well as the increase in tangent loss from 0.03 to 350 upon increasing concentration of TRG in the frequency range of 20-106 Hz. The high dielectric constant values in the low frequency region is mainly attributed to the Maxwell-Wagner polarization effect, while high values of tangent loss is contributed from the current leakage through the electrically conducting network of TRG sheets formed within the TPU matrix at high filler loadings.
Electrochemical reactivity of carbonaceous materials for water treatment and energy recovery
(2018-03-18)
Doong, Ruey-An
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Chang, Pei-Yi
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Hsu, Chia-wen
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環境工程研究所
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Institute of Environmental Engineering
Enhanced catalytic reduction of nitrophenols by sodium borohydride over highly recyclable Au@graphitic carbon nitride nanocomposites
(2018-08-19)
Binh Nguyen
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Doong, Ruey-An
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Huang, Chin-Pao
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環境工程研究所
;
Institute of Environmental Engineering
Enhanced reactivity of metal/metal oxide-porous carbon nanocomposites for electrochemical and photocatalytic applications
(2016-08-20)
Doong, Ruey-An
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Lin, Chia-Sheng
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Bindumadhavan, Kartick
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環境工程研究所
;
Institute of Environmental Engineering
Enhanced visible-light-responsive photocatalytic degradation of emerging pollutants by ZnFe2O4/TiO2 heterostructures
(2017-04-02)
Doong, Ruey-An
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環境工程研究所
;
Institute of Environmental Engineering
Enhanced visible-light-responsive photodegradation of bisphenol A by Cu, N-codoped titanate nanotubes prepared by microwave-assisted hydrothermal method
(2017-01-15)
Doong, Ruey-An
;
Liao, Chun-Yi
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環境工程研究所
;
Institute of Environmental Engineering
In this study, a rapid and effective microwave-assisted hydrothermal method was developed for the synthesis of Cu, N-codoped titanate nanotubes (Cu, N-TNTs) to enhance the photocatalytic degradation efficiency and rate of bisphenol A (BPA) under UV and visible light irradiations. The TNTs were first synthesized at 150 degrees C for 3 h under microwave heating conditions followed by the calcination at 450 degrees C in the presence of 6 wt% Cu ions and N-2/NH3 to fabricate Cu, N-TNTs composites. The Cu, N-TNTs exhibited excellent photocatalytic activity toward BPA degradation under UV and visible light irradiations. The X-ray photoelectron spectra indicated that Cu species in Cu, N-TNTs were mainly in zerovalent form and could serve as the electron donors as well as shuttling species to accelerate the photodegradation of BPA. In addition, the nitrogen atoms were incorporated into the anatase lattices to increase the visible light-responsive capability. The surface normalized reaction rate constants for BPA degradation were 4.3 and 1.5 times higher than those of Degussa P25 TiO2 under UV and visible light irradiations, respectively. The electron spin resonance spectra showed that Cu, N-codoped TNTs prolonged the generation of oxygen-containing radicals for at least 5 min, resulting in the significant enhancement of photodegradation efficiency and rate of BPA. Results obtained in this study open a new avenue by using simple and effective microwave-assisted hydrothermal method to fabricate low dimensional codoped TNTs which can be potentially applied in a wide variety of fields of purification, green chemistry and photocatalysis. (C) 2016 Elsevier B.V. All rights reserved.
Fabrication of titanate nanotube-supported carbon-zerovalent iron nanocomposites for enhanced dechlorination of tricholoroethyelen
(2016-03-13)
Doong, Ruey-An
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Tsou, Feng-Ju
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環境工程研究所
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Institute of Environmental Engineering
Graphene Quantum Dots Decorated Gold-Polyaniline Nanowire for Impedimetric Detection of Carcinoembryonic Antigen
(2019-05-10)
Ganganboina, Akhilesh Babu
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Doong, Ruey-An
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環境工程研究所
;
Institute of Environmental Engineering
A label-free impedimetric immunosensor based on N, S-graphene quantum dots@Au-polyani line (N, S-GQDs@Au-PANI) nanowires was fabricated for the quantitative detection of carcinoembryonic antigen (CEA). The N, S-GQDs and Au-PANI were synthesized by a simple hydrothermal pyrolysis and interfacial polymerization, respectively. Subsequently, 2-9 nm N, S-GQDs are successfully decorated onto 30-50 nm Au-PANI nanowires by Au-thiol linkage to serve as the bifunctional probe for amplifying the electrochemical activity as well as anchoring anti-CEA. The N, S-GQDs@Au-PANI nanowires are excellent conducting materials to accelerate the electron transfer, while the formation of CEA antibodyantigen bioconjugates after the addition of CEA significantly increase the charge transfer resistance, and subsequently provides a highly stable and label-free immunoassay platform for the impedimetric detection of CEA. The label-free immunosensor exhibits a wide linear range from 0.5 to 1000 ng mL(-1) with a low detection limit of 0.01 ng mL(-1). The N, S-GQDs@Au-PANI based immunosensor also shows high selectivity and stability over other cancer makers and amino acids. Moreover, this promising platform is successfully applied to the detection of CEA in human serum samples with excellent recovery of (96.0 +/- 2.6)-(103 +/- 3.8)%. These results clearly demonstrate a newly developed highly efficient and label-free impedimetric immunosensor for the detection of CEA using N, S-GQDs@Au-PANI nanowires as the biosensing probe, which can pave the gateway for the fabrication of high performance and robust impedimetric immunosensor to detect cancer makers in early stage of cancer diagnosis and therapy.
Graphene quantum dots decorated iron oxide and halloysite nanotubes for high performance supercapacitor
(2018-08-19)
Ganganboina, Akhilesh Babu
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Doong, Ruey-An
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環境工程研究所
;
Institute of Environmental Engineering
Graphene quantum dots embedded V2O5 nanosheets as high-performance supercapacitor
(2019-03-31)
Ganganboina, Akhilesh Babu
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Sheng-Mu, You
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Doong, Ruey-An
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環境工程研究所
;
Institute of Environmental Engineering
Immobilization of bimetallic zerovalent iron nanoparticles onto low dimensional supports for enhanced hydrodechlorination of trichloroethylene
(2018-08-19)
Saha, Rama Shanker
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Tsou, Feng-Ju
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Doong, Ruey-An
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環境工程研究所
;
Institute of Environmental Engineering
Insights into the rapid elimination of antibiotics from aqueous media by tunable C3N4 photocatalysts: Effects of dopant amount, co-existing ions and reactive oxygen species
(2019-06-15)
de Luna, Mark Daniel G.
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Paragas, Larah Kriselle B.
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Doong, Ruey-An
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環境工程研究所
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Institute of Environmental Engineering
Conventional photocatalytic nanomaterials are not environmentally sustainable since these are usually produced from scarce mineral and metal precursors. Moreover, high pollutant removal efficiencies by conventional photocatalysts are only attained after several hours of reaction with light. In this study, novel visible light-active photocatalysts were synthesized from environment-friendly carbon precursors and applied for the rapid degradation of sulfamethoxazole (SMX) in aqueous solutions. The photocatalysts were prepared via the co-pyrolysis of urea with varying doping temperature and dopant amount. These variations played a vital role in improving the performance of the photocatalysts and resulted in up to >99% SMX removal within 45 min of visible light irradiation. Characterization of the photocatalysts showed that potassium and iodine dopants were responsible in the red shift and broadening of the light absorption spectrum to the visible region. In addition, the band gap energy narrowed by 0.23 eV resulting in faster charge transfer but slower recombination of the photo-generated electron and hole pairs. Effects of varying concentrations of inorganic salts (NO3-, SO42-, Cl-, PO43-) on SMX removal were also examined. Lastly, the mechanism of SMX photodegradation was elucidated. (C) 2019 Elsevier B.V. All rights reserved.
Label-free impedimetric immunosensor based on N, S-GQDs decorated Au-PANI for selective detection of carcinoembryonic antigen
(2019-03-31)
Ganganboina, Akhilesh Babu
;
Doong, Ruey-An
;
環境工程研究所
;
Institute of Environmental Engineering
N-Doped Graphene Quantum Dots-Decorated V2O5 Nanosheet for Fluorescence Turn Off-On Detection of Cysteine
(2018-01-10)
Ganganboina, Akhilesh Babu
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Chowdhury, Ankan Dutta
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Doong, Ruey-An
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環境工程研究所
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Institute of Environmental Engineering
The development of a fast-response sensing technique for detection of cysteine can provide an analytical platform for prescreening of disease. Herein, we have developed a fluorescence turn off-on fluorescence sensing platform by combining nitrogen-doped graphene quantum dots (N-GQDs) with V2O5 nanosheets for the sensitive and selective detection of cysteine in human serum samples. V2O5 nanosheets with 2-4 layers are successfully synthesized via a simple and scalable liquid exfoliation method and then deposited with 2-8 nm of N-GQDs as the fluorescence turn off-on nanoprobe for effective detection of cysteine in human serum samples. The V2O5 nanosheets serve as both fluorescence quencher and cysteine recognizer in the sensing platform. The fluorescence intensity of N-GQDs with quantum yield of 0.34 can be quenched after attachment onto V2O5 nanosheets. The addition of cysteine triggers the reduction of V2O5 to V4+ as well as the release of N-GQDs within 4 min, resulting in the recovery of fluorescence intensity for the turn off-on detection of cysteine. The sensing platform exhibits a two-stage linear response to cysteine in the concentration range of 0.1-15 and 15-125 mu M at pH 6.5, and the limit of detection is 50 nM. The fluorescence response of N-GQD@V2O5 exhibits high selectivity toward cysteine over other 22 electrolytes and biomolecules. Moreover, this promising platform is successfully applied in detection of cysteine in human serum samples with excellent recovery of (95 +/- 3.8) - (108 +/- 2.4)%. These results clearly demonstrate a newly developed redox reaction-based nanosensing platform using N-GQD@V2O5 nanocomposites as the sensing probe for cysteine-associated disease monitoring and diagnosis in biomedical applications, which can open an avenue for the development of high performance and robust sensing probes to detect organic metabolites.
PMSE 421-Study of the adsorption of a cationic surfactant on photoresist surfaces
(2006-09-10)
Chang, Sue-Min
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Cheng, Han-Yun
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Kao, I-Ling
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Doong, Ruey-An
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環境工程研究所