Hydrothermal synthesis of In₂O₃ nanocubes for highly responsive and selective ethanol gas sensing

Nguyen, Thuy T.D.,Choi, Ha-Nui,Ahemad, M. Jamir,Van Dao, Dung,Lee, In-Hwan,Yu, Yeon-Tae Elsevier 2020 Journal of Alloys and Compounds Vol.820 No.-

<P><B>Abstract</B></P> <P>Indium oxide nanocubes (NCs) were prepared via a simple, template-free hydrothermal method at low temperature; the so-obtained structures exhibited large surface area (47.67 m<SUP>2</SUP>/g) and Barrett−Joyner−Halenda (BJH) adsorption average pore diameter (11.92 nm), both higher than for commercial In<SUB>2</SUB>O<SUB>3</SUB> nanoparticles. At the optimal temperature of 300 °C, the In<SUB>2</SUB>O<SUB>3</SUB> NCs-based sensor showed a superior response of 85–100 ppm ethanol, 3.4 times higher than that of the commercial one based on In<SUB>2</SUB>O<SUB>3</SUB> NPs, and also faster response time (15 s) than the commercial device (60 s). The better sensing performance of the synthesized In<SUB>2</SUB>O<SUB>3</SUB> NCs can be attributed to its unique properties that include large BET surface area and BJH adsorption average pore diameter as well as abundance of sharp edges and tips, which result in high surface to volume ratios for the gas adsorption and diffusion processes, facilitating the charge-transfer and sensing reactions at the gas–solid interfaces. In addition, the In<SUB>2</SUB>O<SUB>3</SUB> NCs exhibited excellent selectivity to ethanol among other target gases (CO, CH<SUB>4</SUB>, CH<SUB>3</SUB>CHO, H<SUB>2</SUB>, and CH<SUB>3</SUB>COCH<SUB>3</SUB>). This work provides an effective design pathway for ethanol sensors based on In<SUB>2</SUB>O<SUB>3</SUB> NCs.</P> <P><B>Highlights</B></P> <P> <UL> <LI> In<SUB>2</SUB>O<SUB>3</SUB> nanocubes are prepared via a template-free method at low temperature. </LI> <LI> In<SUB>2</SUB>O<SUB>3</SUB> nanocubes show high surface area and large BJH adsorption pore diameter. </LI> <LI> In<SUB>2</SUB>O<SUB>3</SUB> nanocubes show high sensing response and good selectivity to ethanol gas. </LI> <LI> Our finding opens an effective pathway to develop ethanol sensors. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>The graphical abstract for In<SUB>2</SUB>O<SUB>3</SUB> nanocubes ethanol gas sensing.</P> <P>[DISPLAY OMISSION]</P>

The Role of Social Trust on Property Right Protection: Physical Property Versus Intellectual Property

Nguyen Thuy T.,Duong Tien H.,Dinh My T. T.,Truong Thu T. M.,Pham Tram H. H. 한국국제경제학회 2023 International Economic Journal Vol.37 No.2

While there have been numerous papers analyzing the political, economic and social effects of trust, there is little evidence on how social trust has an impact on property rights protection which is fundamental for promoting economic development. This study aims to investigate how trust value is related to property rights protection, focusing on the comparison of the effect on intellectual property rights versus physical property rights. Analyzing the data on property rights protection in 2015 from the Property Right Alliance organization and trust value from the World Value Survey from 1999 to 2014, we find that social trust has a direct effect only on intellectual property rights protection but less consistent on physical property rights protection. However, trust value has indirect effect on both forms of property rights protection via formal institutions. Our study, thus, adds to the literature by clarifying the context through which trust value affects cheating behaviors.

Microbial Inactivation by Cupric Ion in Combination with H₂O₂: Role of Reactive Oxidants

Nguyen, Thuy T. M.,Park, Hee-Jin,Kim, Jee Yeon,Kim, Hyung-Eun,Lee, Hongshin,Yoon, Jeyong,Lee, Changha American Chemical Society 2013 Environmental science & technology Vol.47 No.23

<P>The cupric ion mediated inactivation of Escherichia coli was enhanced by the presence of hydrogen peroxide (H<SUB>2</SUB>O<SUB>2</SUB>), with increasing inactivation efficacy observed in response to increasing concentrations of H<SUB>2</SUB>O<SUB>2</SUB>. The biocidal activity of the Cu(II)/H<SUB>2</SUB>O<SUB>2</SUB> system is believed to result from the oxidative stress caused by reactive oxidants such as the hydroxyl radical (<SUP>•</SUP>OH), cupryl species (Cu(III)), and the superoxide radical (O<SUB>2</SUB><SUP>•–</SUP>), which are produced via the catalytic decomposition of H<SUB>2</SUB>O<SUB>2</SUB>. In E. coli cells treated with Cu(II) and H<SUB>2</SUB>O<SUB>2</SUB>, the intracellular level of <SUP>•</SUP>OH and Cu(III) increased significantly, leading to complete disruption of cell membranes. On the basis of experimental observations made using an <SUP>•</SUP>OH scavenger, copper-chelating agents, and superoxide dismutase, it is concluded that Cu(III) is the predominant species responsible for the death of E. coli cells. It was also found that the production of Cu(III) was promoted by the reactions of copper with intracellular O<SUB>2</SUB><SUP>•–</SUP>. MS2 coliphage was found to be even more susceptible than E. coli to the oxidative stress induced by the Cu(II)/H<SUB>2</SUB>O<SUB>2</SUB> system.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/esthag/2013/esthag.2013.47.issue-23/es403155a/production/images/medium/es-2013-03155a_0006.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/es403155a'>ACS Electronic Supporting Info</A></P>

Promoting Higher Education Cooperation between the European Union and Asia: The Case of Vietnam

( Chau T. M. Ly ),( Thuy T. T. Nguyen ),( Uyen T. Nguyen ),( Long T. Nguyen ) 한국EU학회 2019 Asia-Pacific Journal of EU Studies Vol.17 No.1

With regards to the cooperation between European countries and Asia in higher education Higher Education is a top priority both for Europe and the Vietnamese Government. In the context of Vietnam, Vietnam-European Union universities cooperation gets more opportunities for bilateral and multilateral cooperation on joint-training programmes, collaborative research projects, students and lecturers exchange programmes and exchange scholarships. There has also been more cooperation under research projects funded under ERASMUS. The paper summaries the higher education cooperation between European and Asia focusing the case of Vietnam, raised the challenges in terms of partner universities and the contributions of the cooperation regarding the mobility partnerships to enhancing the international cooperation capacity of the higher education institutions involved and reinforcing the capacity and internationalisation of higher education thus contributing also to raising the prestige and international recognition. The paper presents the impact of European cooperation programmes in Vietnam and concludes some remarks to promote the higher education cooperation between Europe and Asia.

Highly selective and sensitive optosensing of glutathione based on fluorescence resonance energy transfer of upconversion nanoparticles coated with a Rhodamine B derivative

Nguyen, Thu-Thuy T.,Huy, Bui The,Tawfik, Salah M.,Zayakhuu, Gerelkhuu,Cho, Hyo Hyun,Lee, Yong-Ill Elsevier 2020 Arabian journal of chemistry Vol.13 No.1

<P><B>Abstract</B></P> <P>A Glutathione (GSH) optical sensor with high sensitivity and exceptional selectivity was developed using one-step synthesized-upconversion nanoparticles (UCNPs, NaLuF<SUB>4</SUB>:Gd<SUP>3+</SUP>,Yb<SUP>3+</SUP>,Er<SUP>3+</SUP>) in conjunction with a Rhodamine B derivative (RBD). RBD was loaded on the surface of the UCNPs though non-covalent bonding to serve as an energy acceptor, while UCNPs served as energy donors. The sensor based on a coupling fluorescence resonance energy transfer (FRET) process at an excitation of 980 nm wavelength from UCNP to RBD with a ring-opening process of RBD after the addition of GSH. The sensing probe exhibits a remarkable limit of detection (LOD = 50 nM) for GSH through the enhancement of the fluorescence intensity of RBD at 592 nm, together with a concomitant reduction in the green band of the UCNPs. In addition, the sensing mechanism, characterization of UCNPs, and the selectivity of the fluorescence sensor toward GSH were discussed. The proposed sensor was evaluated on real human serum and urine samples and demonstrated as a highly selective and sensitive probe for the detection of GSH.</P>

영가철 및 영가구리 나노입자를 활용한 수중 미생물 불활성화

이창하,( Thuy T. M. Nguyen ),김지연,윤제용 한국공업화학회 2011 한국공업화학회 연구논문 초록집 Vol.2011 No.1

Synthesis and characterization of metal-doped reduced graphene oxide composites, and their application in removal of Escherichia coli, arsenic and 4-nitrophenol

Shashi Prabha Dubey,권영남,Thuy T.M. Nguyen,이창하 한국공업화학회 2015 Journal of Industrial and Engineering Chemistry Vol.29 No.-

The aim of the present study is to synthesize dispersible reduced graphene oxide (RGO) viafunctionalization with metals and metal oxides and explore their potential applications in waterpurification. Graphene-based metal and metal oxide composites were synthesized hydrothermally usingsodium borohydride as a reducing agent and sodium sorbate as a stabilizer. Single (Ag, Cu2O, and Fe3O4)and bimetallic (Ag-Cu2O, Ag-Fe3O4, and Cu2O-Fe3O4) nanoparticles were incorporated on the surface ofRGO. The synthesized composites were characterized by various analytical methods. The inactivation ofE. coli, the catalytic degradation of 4-nitrophenol, and the adsorption of As(V) were examined using theRGO composites.

Role of Reactive Oxygen Species in <i>Escherichia coli</i> Inactivation by Cupric Ion

Park, Hee-Jin,Nguyen, Thuy T. M.,Yoon, Jeyong,Lee, Changha American Chemical Society 2012 Environmental science & technology Vol.46 No.20

<P>This study demonstrated <I>Escherichia coli</I> inactivation by cupric ion (Cu[II]), focusing on intracellular generation and consumption of reactive oxygen species (ROS) including superoxide and hydroxyl radials. In the presence of Cu(II), intracellular superoxide levels of <I>E. coli</I> decreased in a concentration-dependent manner, indicating that superoxide radical was used to reduce Cu(II) to Cu(I) in cells. The variation in the hydroxyl radical level by adding Cu(II) was negligible. Molecular oxygen and hydroxyl radical scavengers did not affect the inactivation efficacy of <I>E. coli</I> by Cu(II), excluding the possibility that hydroxyl radicals induced by the copper-mediated reduction of oxygen contributed to the microbiocidal action of Cu(II). However, the inactivation of <I>E. coli</I> by Cu(II) was considerably inhibited and accelerated by a Cu(I)-chelating agent and a Cu(II)-reducing agent, respectively. Our results suggest that the microbiocidal action of Cu(II) is attributable to the cytotoxicity of cellularly generated Cu(I), which does not appear to be associated with oxidative damage by Cu(I)-driven ROS.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/esthag/2012/esthag.2012.46.issue-20/es302379q/production/images/medium/es-2012-02379q_0002.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/es302379q'>ACS Electronic Supporting Info</A></P>

Study on Novel Topology of Solar–Wind Hybrid Power Plant Using Photovoltaic Cell Emulating System

Vu Minh Phap,N. Yamamura,M. Ishida,Nguyen Thuy Nga,I. Mizoguchi,T. Yamashita 대한전기학회 2019 Journal of Electrical Engineering & Technology Vol.14 No.2

At the present, the grid-tied solar power system is the most promising as a renewable energy technology for replacing the fossil energy sources. The usage effi ciency of the power conditioner system in the grid-tied solar power system is not high because the electricity generation from solar panels depends on the weather. The utilization rate of the power conditioner system can be increased by adding the small scale wind turbine to the existing grid-tied solar power system. We introduced a novel design solution in the previous study to connect the small wind turbine with the power conditioner system of the grid-tied solar power system by emulating technical characteristics of the solar panel in series connection mode. By which, the utilization rate of the power conditioner system has been increased. However, this improved utilization rate of the power conditioner system is not high in the cloudy and rainy days because the voltage of the solar panel changes slightly and the maximum input voltage of the power conditioner system is limited. Therefore, we propose a novel performance enhancement method for solar–wind hybrid power plant using photovoltaic cell emulating system in this research.