Co₉S₈@MoS₂ core-shell nanostructure anchored on reduced graphene oxide with improved electrochemical performance for lithium-ion batteries

Ren, Haibo,Gu, Cuiping,Zhao, Jingjuan,Joo, Sang Woo,Huang, Jiarui Elsevier 2019 APPLIED SURFACE SCIENCE - Vol.473 No.-

<P><B>Abstract</B></P> <P>Co<SUB>9</SUB>S<SUB>8</SUB>@MoS<SUB>2</SUB> core-shell nanoparticles anchored on both sides of reduced graphene oxide (Co<SUB>9</SUB>S<SUB>8</SUB>@MoS<SUB>2</SUB>/rGO) were synthesized via hydrothermal reaction. The core-shell composites were used as an anode material and demonstrated enhanced electrochemical performance with high capacity, capacity retention, cycling stability, and rate capability during cycling tests. The nanocomposites deliver a reversible capacity of 2014.5 mAh g<SUP>−1</SUP> at a high rate of 0.3 A g<SUP>−1</SUP> with a capacity retention efficiency of 82.8% after 200 cycles. The reduced graphene oxide-based three-dimensional framework of the core-shell structure can reduce the internal resistance of the whole electrode, facilitate more Li<SUP>+</SUP> ion insertion and extraction from the crystal structure, and relieve the strain caused by volume change during the lithiation/delithiation process. The electrochemical behaviors could make the composites a great potential anode material for lithium-ion batteries.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Co<SUB>9</SUB>S<SUB>8</SUB>@MoS<SUB>2</SUB> core-shell nanostructure anchored on rGO was developed. </LI> <LI> It involves two-step hydrothermal reaction. </LI> <LI> The Co<SUB>9</SUB>S<SUB>8</SUB>@MoS<SUB>2</SUB>/rGO composites exhibit high stable capacity and rate performance. </LI> <LI> High performance is ascribed to the special hierarchical core-shell nanostructure. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Preparation of porous flower-like SnO₂ micro/nano structures and their enhanced gas sensing property

Ren, Haibo,Zhao, Wei,Wang, Liyou,Ryu, Si Ok,Gu, Cuiping Elsevier 2015 JOURNAL OF ALLOYS AND COMPOUNDS Vol.653 No.-

<P><B>Abstract</B></P> <P>Porous flower-like tin oxide (SnO<SUB>2</SUB>) structures were obtained using a hydrothermal method combined with a subsequent calcination and acid-washing process. The morphologies and crystal structures of the products were characterized by field emission scanning electron microscopy, transmission electron microscopy, energy dispersive spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and Brunauer–Emmett–Teller N<SUB>2</SUB> adsorption-desorption analyses. The process of inducing porosity begins with a flower-like nickel tin sulfur precursor. Thermal decomposition of this flower-like nickel tin sulfur precursor leads to an intimate mixture of porous flower-like NiO/SnO<SUB>2</SUB> hybrids. Porous SnO<SUB>2</SUB> flowers were obtained after removing the cubic phase NiO by an acid-washing process. Furthermore, the gas sensing properties of the as-prepared porous SnO<SUB>2</SUB> flowers to VOCs, such as ethanol, formaldehyde, benzene, toluene, and acetone, were investigated. The porous SnO<SUB>2</SUB> flowers showed a good response and reversibility to some organic vapors, such as ethanol and formaldehyde. The sensing responses to 100 ppm ethanol and formaldehyde were 42.4 and 24.8, respectively. The sensors also exhibited a good response to benzene, toluene, methanol, and 2-propanol. The relationship between the gas-sensing properties and the microstructure of the as-prepared flower-like SnO<SUB>2</SUB> structures was also examined.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Flower-like nickel tin sulfur structures were synthesized by hydrothermal method. </LI> <LI> Porous SnO<SUB>2</SUB> microflowers were obtained by treatment of the precursor. </LI> <LI> Porous SnO<SUB>2</SUB> microflowers exhibited excellent sensing properties to some gases. </LI> <LI> Excellent gas-sensing properties were attributed to the special 3D structures. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Effective hydrogen gas sensor based on NiO@rGO nanocomposite

Ren, Haibo,Gu, Cuiping,Joo, Sang Woo,Zhao, Jingjuan,Sun, Yufeng,Huang, Jiarui Elsevier 2018 Sensors and actuators. B Chemical Vol.266 No.-

<P><B>Abstract</B></P> <P>A NiO@rGO nanocomposite is prepared by a freeze-drying method combined with heat treatment. The morphology and structure are analyzed through X-ray diffraction, scanning electron microscopy, transmission electron microscopy, Raman spectra, and X-ray photoelectron spectroscopy. The results clearly show that NiO nanoparticles are uniformly anchored on the surface of the rGO nanosheet. The gas-sensing performance of the nanocomposite is also investigated to detect hydrogen. The NiO@rGO sensor exhibits good gas-sensing performance with high sensitivity, fast response, good reversibility, and selectivity toward hydrogen. The relative response of the sensor to 1% hydrogen is 0.64, the response time is 28 s, and the recovery time is 142 s. The improved sensing performance is due to the effective electron transfer between the NiO nanoparticles and rGO nanosheet.</P> <P><B>Highlights</B></P> <P> <UL> <LI> NiO@rGO nanocomposite consisting of NiO NPs uniformly anchored on rGO is developed. </LI> <LI> The preparation method involves freeze-drying followed by heat treatment. </LI> <LI> NiO@rGO sensor shows high response and selectivity to H<SUB>2</SUB> at low working temperature. </LI> <LI> High performance is ascribed to the electron transfer between NiO NPs and rGO. </LI> </UL> </P>

한·중 비대면 보험판매규제의 비교 고찰

임해파(Haibo Ren),맹수석(Sooseok Maeng) 한국법학회 2012 법학연구 Vol.45 No.-

한국과 중국 양국의 보험상품통신판매시장은 인터넷 등 정보통신기술의 발달로 인해 급성장하고 있다. 한국과 마찬가지로 중국의 경우도 주로 표준화가 용이한 보험상품을 대상으로 비대면 판매가 이루어지고 있는데, 이를 규율하기 위한 법제 정비를 지속적으로 해오고 있다. 즉 중국은 인터넷을 통한 상품거래를 전반적으로 규율하기 위해 2010년 7월 「인터넷 상품교역규칙」을 제정하였고, 특히 인터넷을 통한 보험상품 판매를 규율하기 위해 2011년 5월 「인터넷 보험 의견 모음 기준」을 제정?시행하였다. 그리고 전화판매에 의한 재산보험상품은 「재산보험회사 TM판매 통지」와 이를 보완한 「재산보험회사 TM판매 강화통지」에 의해, 인보험상품은 「인보험회사 TM 판매 통지」와 「인보험회사 TM판매 강화 통지」에 의해 규율되고 있다. 그러나 TV 홈쇼핑판매의 경우는 TV홈쇼핑을 통한 보험상품 판매가 그다지 활발하지 않기 때문에, 이에 관한 직접적인 규정은 아직 존재하지 않고, 일반적인 상품에 대한 규칙인 「라디오?TV 광고방송의 잠정적 관리 규칙」과 「TV홈쇼핑 통지」에 의해 이루어지고 있다. 중국의 이러한 규제 내용은 우리나라와 유사하지만,TV홈쇼핑 보험판매의 활성화 정도 및 외국보험회사에 대한 자본금의 차이 여부, 규정 내용에서 인터넷 판매와 전화판매를 별도로 규율하는지 여부, 현장검사 및 감독관리 책임제의 여부, 전화판매상품의 제한 범위, 보험관리비용에 대한 강제 여부, 관할권 등에 있어서 차이가 있다. 이 논문에서는 최근 중국의 보험상품 통신판매에 관한 현황 및 규제 법규를 우리나라와 비교하면서, 법적 쟁점을 고찰해 보았다. In Korea and China, the direct response insurance market is rapidly growing with the advancement of the Internet. This study is to compare Korea and China in the present state of the direct response insurance market and relevant regulations. In China, the direct response sales are focused on standardizable products. On July 2010, Internet Transaction Regulations was enacted with a view to regulate internet transactions. In particular, Internet Insurance Survey Standards, set up on May 2011, are to regulate insurance sales on the Internet. Direct-response property insurances are regulated by Notification on the Telemarketing of Property Insurance Companies and the tightened notification. Likewise, personal insurances are by Notification on the Telemarketing of Personal Insurance Companies and the tightened notification. On the other hand, there has been no regulation on insurance sales through TV home shopping networks, because they have not been common yet. Instead, they are regulated by Tentative Regulations on Radio and TV Advertisements and Notification on TV Home Shopping. The foregoing regulations are similar to those of Korea, but they have different views as to how much insurance sales flourish through TV home shopping networks, how much difference there is in capital with foreign insurance companies, whether such regulations distinguish internet transactions from telemarketing, whether on-the-spot investigations and superintendence are conducted, whether limits are set on direct-response products and insurance management fees, and how jurisdictions are arranged.

Prediction on the physical properties of CuInS2 with various anion positions

Yiming Ren,Yonghong Hu,Haibo Zeng,Li Xue 한국물리학회 2018 Current Applied Physics Vol.18 No.3

The effects of various anion displacements (u) on electronic structures, elastic constants, Debye temperature and the minimum thermal conductivity of CuInS2 are studied by first-principles calculation. The lattice constant couples with the anion displacement, however, they are not consistent with the relation proposed by Abrahams and Bernstein. When the anion displacement varies from 0.2 to 0.3, the Cu-S bond length is elongated, while the In-S bond length is shortened, which cause the increase of band gap with anion displacement. The anisotropies of sound velocities and lattice thermal conductivities are also discussed. The results imply that the lattice thermal conductivity along [110] direction is the smallest and decreases with u. These research findings shed light on improving the thermoelectric properties by manipulating u and the direction of propagation.

Study on thermal buckling and post-buckling behaviors of FGM tubes resting on elastic foundations

She, Gui-Lin,Ren, Yi-Ru,Xiao, Wan-Shen,Liu, Haibo Techno-Press 2018 Structural Engineering and Mechanics, An Int'l Jou Vol.66 No.6

This paper studies thermal buckling and post-buckling behaviors of functionally graded materials (FGM) tubes subjected to a uniform temperature rise and resting on elastic foundations via a refined beam model. Compared to the Timoshenko beam theory, the number of unknowns of this model are the same and no correction factors are required. The material properties of the FGM tube vary continuously in the radial direction according to a power function. Two ends of the tube are assumed to be simply supported and in-plane boundary conditions are immovable. Energy variation principle is employed to establish the governing equations. A two-step perturbation method is adopted to determine the critical thermal buckling loads and post-buckling paths of the tubes with arbitrary radial non-homogeneity. Through detailed parametric studies, it can be found that the tube has much higher buckling temperature and post-buckling strength when it is supported by an elastic foundation.

Facile Synthesis of Fluorine Doped Graphitic Carbon Nitride with Enhanced Visible Light Photocatalytic Activity

Mengqiu Xu,Bo Chai,Juntao Yan,Haibo Wang,Zhandong Ren,Kyung-Wook Paik 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2016 NANO Vol.11 No.12

Fluorine doped graphitic carbon nitride (g-C3N4) was successfully synthesized by a convenient co-polycondensation of urea and ammonium fluoride (NH4F) mixtures, and characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectra (FTIR), UV-Vis diffuse reflectance absorption spectra (UV-DRS), nitrogen adsorption–desorption, photoelectrochemical measurement and photoluminescence (PL) spectra. The photocatalytic activities of fluorine doped g-C3N4 samples were evaluated by the degradation of Rhodamine B (RhB) solution under visible light irradiation. The results showed that the fluorine doped g-C3N4 had a better photocatalytic activity than that of undoped g-C3N4, which was attributed to the favorable textural, optical and electronic properties derived from the fluorine atoms substituting nitrogen atoms of g-C3N4 frameworks. The photoelectrochemical measurements confirmed that the charges separation efficiency was improved by fluorine doping g-C3N4. Moreover, the tests of radical scavengers demonstrated that the holes (h+) and superoxide radicals (·O- 2 ) were the main active species for the degradation of RhB.

Candesartan-graft-polyethyleneimine Cationic Micelles for Effective Co-delivery of Drug and Gene in Anti-angiogenic Lung Cancer Therapy

Shanhu Hao,Ying Yan,Xue Ren,Ying Xu,Lanlan Chen,Haibo Zhang 한국생물공학회 2015 Biotechnology and Bioprocess Engineering Vol.20 No.3

A multifunctional polymer-drug conjugate candesartan-graft-polyethyleneimine (CD-PEI, CP) containing low molecular weight polyethyleneimine (PEI) and candesartan (CD) conjugated via an amide bond was fabricated as a co-delivery micelle of drug and siRNA for potential lung cancer therapy. Here, CD as an angiotensin II type 1 receptor blocker rich in imidazole and tetrazole rings was utilized to strengthen endosomal buffering capacity of CP and suppress tumor angiogenesis. The selfassembled CP/siRNA complexes exhibited desirable and homogenous particle size, moderate positive charges, and efficient release of drug and siRNA in vitro. In addition, CD and siRNA could readily detached from nanovectors in tumor cells via an amidase-responsive mechanism and they achieved synergistic anti-angiogenesis efficacy by effectively downregulating the expression of vascular endothelial growth factor (VEGF) mRNA and protein via different pathways in vitro. In vivo investigation on nude mice bearing A549 tumor xenografts revealed that CP/siRNA complexes possessed strong antitumor activity. These findings suggested that CP could be an ideal nanovector for simultaneous transfer of drug and siRNA, and a multifunctional CP/siRNA co-delivery system with enhanced endosomal buffering capacity, amidase-responsive drug release and synergistic anti-angiogenesis efficacy might be a new promising strategy for effective lung cancer therapy.

Simulations of water vaporization in novel internal-intensified spouted beds: Multiphase-flow, heat and mass transfer

Xinxin Che,Rong Guo,Feng Wu,Haibo Ren,Wenjing Zhou 한국공업화학회 2022 Journal of Industrial and Engineering Chemistry Vol.116 No.-

Novel internal-intensified spouted beds (SBs) with swirl-nozzle anticlockwise-axial-swirler (SNAAS) andswirl-nozzle clockwise-axial-swirler (SNCAS) were proposed to improve the shortcomings of conventionalSBs. The water vaporization in novel internal-intensified, conventional and swirl-nozzle SBs wassimulated and the multiphase flow behavior and interphase heat and mass transfer in process were analyzed. Simulation results show the co-swirling action of novel combined internal-intensified makes gasdrive particles move helically upward around the axial-swirler. Therefore, compared with conventionaland swirler-nozzle SBs, the radial slip velocity of gas–solid and gas–liquid in two novel SBs are larger,and the contact between gas–liquid-solid phases is more sufficient. The gas–liquid-solid three-phasetemperature, water vaporization rate, and gas moisture content of two novel internal-intensified allreached the highest, indicating that novel combined internal-intensified structures are beneficial to promotingthe interphase heat and mass transfer during the water vaporization process. The mass transferenhancement factors of SNAAS and SNCAS structures are 1.91 and 1.36 times that of conventional SB,respectively.