Institute of Chemistry and Materials

Cau Giay, Vietnam

Institute of Chemistry and Materials

Cau Giay, Vietnam
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La D.D.,RMIT University | Rananaware A.,RMIT University | Thi H.P.N.,Institute of Chemistry and Materials | Jones L.,RMIT University | Bhosale S.V.,RMIT University
Advances in Natural Sciences: Nanoscience and Nanotechnology | Year: 2017

The solar spectrum consists of 8% UV radiation, while 45% of solar energy is from visible light. It is therefore desirable to fabricate a hybrid material which is able to harvest energy from a wide range of photons from the sun for applications such as solar cells, photovoltaics, and photocatalysis. In this study we report on the fabrication of a TiO2@porphyrin hybrid material by surfactant-assisted co-assembly of monomeric porphyrin molecules with TiO2 nanoparticles. The obtained TiO2@porphyrin composite shows excellent integration of TiO2 particles with diameters of 15-30 nm into aggregated porphyrin nanofibers, which have a width of 70-90 nm and are several μm long. SEM, XPS, XRD, FTIR, UV-Vis and fluorescence spectroscopy were employed to characterize the TiO2@TCPP hybrid material. This material exhibits efficient photocatalytic performance under simulated sunlight, due to synergistic photocatalytic activities of the porphyrin aggregates in visible light and TiO2 particles in the UV region. A plausible mechanism for photocatalytic degradation is also proposed and discussed. © 2017 Vietnam Academy of Science & Technology.


Nam N.H.,Vietnam Academy of Science and Technology | Van Bay D.,Hanoi National University of Education | Khue D.N.,New Technology Institute | Van Chung T.,Institute of Chemistry and Materials
Asian Journal of Chemistry | Year: 2013

The adsorbents based on Fe(OH) 3 containing SiO2 and Fe(0) powders (denoted 3TP) were prepared and used for removal of 2,4-dichlorophenoxyacetic acid from water. The characteristics of this adsorbents were determined and indicated that the presence of SiO2 and Fe(0) powders can enhance the amorphous structure of adsorbents, desired for the adsorption. The adsorption of 2,4-dichlorophenoxyacetic acid onto adsorbents was studied. The adsorption process occurs predominantly via chemisorptions of 2,4-dichlorophenoxyacetic acid onto adsorbents. The adsorption characteristics including kinetic thermodynamic parameters were examined. The experimental data shown that this is an endothermic, spontaneous adsorption process.


Chung T.V.,Institute of Chemistry and Materials | Anh T.Q.,Hanoi University | Phung D.Q.,Hanoi National University of Education | Luong T.D.,Hanoi National University of Education
Asian Journal of Chemistry | Year: 2012

The properties of zero-valent iron is useful in remediation of aromatic nitro compounds by reducing them to convert onto the amino products which may also lead to oxidize or mineralize them with the presence of persulfate anion (S 2O 8 2-). In practice, with the zero-valent iron, persulfate anion (E° = 2.01 V) may be activated to produce free sulfate radical (SO 4 - • ) with the higher standard reduction potential (E0 = 2.60 V). It is an active reagent for the mineralization of nitrobenzene in the studied samples. The activation process of persulfate in solution with zero-valent iron to produce SO4 - •, may be implemented by the following pathways: In the heterogeneous system the activation reaction was implemented on iron surface: Fe(0) + 2S 2O 8 2- → Fe 2+ + 2SO 4 - • + 2SO 4 2-, In homogeneous case, the activation process was implemented in solution: Fe 2+ + S 2O 8 2- • → Fe 3+ + SO 4 - • + SO 4 2- In the studied system zero-valent iron is a source producing Fe 2+ to keep the activation of persulfate anion. The free sulfate radical formed in situ oxidizes nitrobenzene causing the decrease of the total organic carbon in the samples. The experimental data have shown that the nitrobenzene concentration of 80 mg/L in the system consisting of 500 mg/L of Na2S2O8 and 1 g/L of zero-valent iron, pH = 5, the efficiency of nitrobenzene mineralization may reach for 98 % for 40 min. The nitrobenzene was first reduced with zero-valent iron then transported for the further oxidation with free sulfate radical, the mineralization nitrobenzene may reach for 95 % for 0.5 h. This means that amine products are easily oxidized than its nitro compounds. The obtained experimental data have suggested that the reduction of nitrobenzene by zero-valent iron may be combined with the oxidation process with persulfate activated with zero-valent iron to enhance the nitrobenzene degradation efficiency and the efficiency of zero-valent iron used. The factors such as ratios of persulfate/zero-valent iron/ nitrobenzene, pH, the addition of Fe 2+ influencing on the efficiency of nitrobenzene mineralization have been investigated.


Chung T.V.,Institute of Chemistry and Materials | Ket N.G.D.,Institute of Chemistry and Materials | Bay D.V.,Hanoi University | Luong T.D.,Institute of Chemistry and Materials | Huong Ng.Th.,Hanoi University
Asian Journal of Chemistry | Year: 2012

2,4,6-Trinitroresorcinol with molecular formula C 6H 3N 3O 8 is one of the aromatic nitro compounds ranging slight to strong oxidizing agents causing environmental contamination. The persulfate anions activated by zero valent iron were used to oxidize organic compounds like trichloroethylene, methyl tertiary butyl ether. This work demonstrates if the zero valent iron activated persulfate oxidation of 2,4,6- trinitroresorcinol was a viable method. The experimental data have shown that the 2,4,6-trinitroresorcinol in aqueous media were oxidized by the persulfate anions activated by zero valent iron. The reaction participated in components such as 2,4,6-trinitroresorcine; its oxidized products were measured by voltammetry square wave and total organic carbon analysis. The reduced total organic carbon values in the reduced samples have demonstrated that the final oxidized products were CO 2 + H 2O + other mineral compounds. The activation of the persulfate anions by zero valent iron may be implemented through the reactions between S 2O 8 2 and zero valent iron to form sulfate free radicals (SO 4 -•). The mineralization of 2,4,6-trinitroresorcinol by the persulfate anions activated by zero valent iron is favour in the pH ranged from 3 to 5.


Tien V.V.,Hanoi National University of Education | Bay D.V.,Hanoi National University of Education | Thu D.X.,Hanoi National University of Education | Chung T.V.,Institute of Chemistry and Materials
Asian Journal of Chemistry | Year: 2015

Arsenic present in water may be determined by many methods such as atomic adsorption spectroscopy, inductively coupled plasma atomic emission spectroscopy, electrochemistry and spectrophotometry with silver diethyldithiocarbamate. This study presents the determination of arsenic present in water by spectrophotometric method based on molybdate reagent. This method is highly sensitive and selective but has not been studied in detail. The obtained results exhibited the experimental optimum conditions for arsenic determination by spectrophotometric method using molybdate reagent. The method consists of two steps (i) arsinization producing AsH3, (ii) AgNO3, H2O2 oxidized AsH3 reacting with molybdate reagent to produce molybdenum blue. The absorbance of molybdenum blue at the wavelength of λ = 878 nm has been used for arsenic determination. The limit of detection and limit of quantitation of the method are 2 and 7 ppb respectively.


Khue D.N.,Institute of Chemistry and Materials | Lam T.D.,Vietnam Academy of Science and Technology | Van Chat N.,Institute of Chemistry and Materials | Bach V.Q.,Institute of Chemistry and Materials | And 3 more authors.
Journal of Industrial and Engineering Chemistry | Year: 2014

Here we report the study on the utilization of several advanced oxidation processes such as electro-oxidation and Fenton process in simultaneous treatment of two nitramine explosives: 2,4,6-trinitrophenyl-N-metylnitramine (Tetryl) and hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX). The preliminary tests indicated that the electrolytic method using a TiO2/IrO2/RuO2-coated electrode could rapidly degrade Tetryl but not RDX. While the addition of certain amount of H2O2 induced an increase of Tetryl degradation yield but had insignificant effect on RDX decomposition, the use of Fenton's reagent showed an enhanced efficiency in degradation of both nitramines. It can be concluded that among tested processes, Fenton process is the most effective for treatment of nitramine-containing wastewaters. © 2013 The Korean Society of Industrial and Engineering Chemistry.


le Trung Q.,Institute of Chemistry and Materials | Duc Hung N.,Institute of Chemistry and Materials | Nam N.H.,Institute of Chemistry and Materials | van Chung T.,Institute of Chemistry and Materials | And 2 more authors.
Asian Journal of Chemistry | Year: 2010

This paper describes the character of the reduction of 2,4.6-trinitroresorcine (TNR) by zero-valent iron (ZVI) in anaerobic conditions and the oxidative reaction of amine resorcine in the system of ZVI-EDTA-O2. The products of TNR by ZVI in anaerobic conditions were amine resorcine compounds. These compounds tend to be easier to be oxidized by the free radical OH• generated in the system of ZVI-EDTA-O2. HPLC method and COD analysis have been used for monitoring efficiency of reactions. The experiments suggested that the removal of TNR from groundwater is likely implemented by two steps. The first step is reduction of TNR by ZVI to form amine resorcine. The second step is oxidation of amine resorcine in system consisting of ZVI-EDTA-O2. From the obtained results a model for TNR contaminated groundwater treatment has been suggested.


Khue D.N.,Institute of Chemistry and Materials | Lam T.D.,Vietnam Academy of Science and Technology | Minh D.B.,Institute of Chemistry and Materials | Loi V.D.,Vietnam Academy of Science and Technology | And 5 more authors.
Journal of Electronic Materials | Year: 2016

The present study focuses on photo-assisted advanced oxidation processes (AOPs) with strongly enhanced electron transfer for degradation of nitro-phenolic compounds in aqueous medium. The effectiveness of these processes was estimated based on the pseudo-first order rate constant k determined from high-performance liquid chromatography. The degradation of four different nitro-phenolic compounds was systematically studied using selected AOPs; these four compounds were nitrophenol, dinitrophenol, trinitrophenol and trinitroresorcin. It was observed that the combination of ultraviolet light with hydrogen peroxide H2O2 enhanced and maintained hydroxyl radicals, and therefore increased the conversion yield of organic pollutants. These AOPs provided efficient and green removal of stable organic toxins found in a wide range of industrial wastewater. © 2016, The Minerals, Metals & Materials Society.


Chung T.V.,Institute of Chemistry and materials | Quang D.S.,Institute of Chemistry and materials | Bay D.V.,Hanoi National University of Education | Luong T.D.,Hanoi National University of Education
Analele Universitatii Bucuresti Chimie | Year: 2011

2,4,6-Trinitroresorcine (TNR) with molecular formula C 6H 3N 3O 8 is one of the aromatic nitro compounds ranging slight to strong oxidizing agents causing environmental contamination. The persulfate anions activated by ZVI were used to oxidize organic compounds like trichloroethylene (TCE), methyl tertiary butyl ether (MTBE). The content of this paper was to demonstrate if the ZVI activated persulfate oxidation of TNR was a viable method. The experimental data have shown that the TNR compounds in aqueous media were oxidized by the persulfate anions activated by ZVI. The reaction participated in components such as TNR; its oxidized products were measured by Voltammetry square wave and TOC analysis. The TOC values in the samples reduced have demonstrated that the final oxidized products were CO 2 + H 2O + other mineral compounds. The activation of the persulfate anions by ZVI may be implemented through the reactions between S 2O 8 2- and ZVI to form sulfate free radicals (SO4 _). The mineralization of TNR by the persulfate anions activated by ZVI is favor in the pH range from 3 to 5. © 2011 Analele Universitǎţii din Bucuresti.


Quoc Trung L.,Institute of Chemistry and Materials | Van Bay D.,Institute of Chemistry and Materials | Minh D.B.,Institute of Chemistry and Materials | Luong T.D.,Institute of Chemistry and Materials | Van Chung T.,Institute of Chemistry and Materials
Asian Journal of Chemistry | Year: 2011

The paper describes the use of voltammetry in monitoring the reductive process of 2,4,6-trinitrotoluene (TNT) to amine compounds by zero-valent iron. This method to simultaneously determine the reduction of TNT and the increase of Fe2+ concentrations in the samples. The method may be applied to establish the efficiency of the conversion process of TNT, the role of zero-valent iron and its efficiency in the reductive process. The factors such as pH, TNT concentration, reaction times and Fe(0) mass influencing on the conversion process into amine compounds have been studied.

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