A Simple Approach to the Ionic-Covalent Bond Based on the Electronegativity and Acid Strength of Cations. Part One:Calculation of the Electronegativity and Acid Strength

Josik Portier,Guy Campet Korean Chemical Society 1997 대한화학회지 Vol.41 No.8

A simple relation exists between electronegativities of cations and their oxidation states and ionic radii. An empirical law is proposed: X = 0.274 z-0.15 z r - 0.01 r+1+${\alpha}$, z being oxidation number, r ionic radius in $\AA$ and ${\alpha}$ a term related to the atomic number. this relation permits to calculate an electronegativity scale covering a large set of electronic and crystallographic situations. An application to the calculation of acid strengths of cations is presented.

A Simple Approach to the Ionic-covalent Bond Based on the Electronegativity and Acid Strength of Cations. Part Two:Application to the Description of the Electronic Properties of Oxides

Josik Portier,Guy Campet Korean Chemical Society 1997 대한화학회지 Vol.41 No.8

The acid strngth of cations, determined with ICP (Ionic Covalent Parameter): ICP=log(P)-1.38x+2.07 where P is the polarizing power and X its electronegativity expresses the competition between the covalent and ionic forces. This concept, together with electronegativity, is used to describe the properties of oxides with various electronic properties (insulators, metals, degenerate semiconductors, superconductors).

Application of Hybrid Polymeric Complexes to Solid State and Materials Chemistry

Josik Portier,Guy Campet,Nadine Treuil,Armel Poquet,Kim, Young Il,Kwon, Soon Jae,Kwak, Seo Young,Choy, Jin Ho Korean Chemical Society 1998 대한화학회지 Vol.42 No.4

A bird's-eye view on preparation, structure and properties of polymeric complexes in the field of Inorganic-Organic-Hybrids is presented in the view point of solid state and materials chemistry. These materials are useful precursors for preparing nanoparticles and fine grain oxides. Some of them are electroactive and are used as protonic or lithium electrolytes, electrochromic materials or membranes for sensors and actuators. New results on bio-hybrids, a class of material not far from polymeric complexes, are also described.

Enhanced PEC characteristics for CdSe polycrystalline film electrodes prepared by combined electrochemical/chemical bath depositions

Zyoud, A.,Abdul-Rahman, N.N.,Campet, G.,Park, D.,Kwon, H.,Kim, T.W.,Choi, H.J.,Helal, M.H.S.,Hilal, H.S. Elsevier Sequoia 2016 Journal of Electroanalytical Chemistry Vol.774 No.-

<P>Polycrystalline CdSe films have been deposited onto fluorine doped tin oxide (FTO/glass) substrates by three different techniques, electrochemical deposition (ECD), chemical bath deposition (CBD) and, for the first time, combined ECD and CBD (ECD/CBD). The films were comparatively characterized-by photoluminescence spectra (PL), electronic absorption spectra, scanning electron microscopy (SEM) and X-ray diffraction (XRD). The SEM micrographs show that the films involved rod shaped agglomerates with various lengths and widths. XRD patterns show that the three systems involved nano-sized CdSe particles with cubic type crystals. Based on Scherrer's equation, the ECD film showed larger particle size than the CBD film, while the ECD/CBD film showed largest particles among the series. Similarly, the band gap values varied for different films as CBD > ECD > ECD/CBD. Photo electrochemical (PEC) characteristics, including photo-current density vs. voltage (J-V) plots, conversion efficiency (eta), fill factor (FF) and stability were all studied for different film electrodes. The films exhibited n-type behaviors with direct band gaps. The new ECD/CBD-CdSe electrode exhibited higher conversion efficiency (eta%similar to 4.40) than other counterparts. The results show the added value of combining ECD and CBD methods in enhancing PEC characteristics of CdSe film electrodes, even with no additional treatment. (C) 2016 Elsevier B.V. All rights reserved.</P>

RF Sputtered Lithium Nickel Oxide Films and Their Electrochromism

Kim, Young-Il,Kim, Bae-Whan,Choy, Jin-Ho,Campet, Guy,Park, Nam-Gyu,Portier, Josik,Morel, Bertrand Korean Chemical Society 1997 대한화학회지 Vol.41 No.11

RF 스피터링법을 써서 $Li_{2x}Ni_{1-x}O$ 박막을 제조하였으며, 그 과정에서 기판의 온도$(50/230^{\circ}C)와$ 분위기 $(Ar/O_2)$를 변수로써 막의 미세구조를 조절하였다. 투과전자현미경을 이용한 막 구조 분석에 의해 낮은 기판 온도와 $O_2$ 조건에서 막의 조성입자가 작아짐을 관찰하였고, $50^{\circ}C/O_2$ 하에서 얻이진 $Li_{2x}Ni_{1-x}O$ 박막은 약 $80\AA$ 크기의 입자로 이루어져 있었다. 전기화학적 조건 하에서 $Li_{2x}Ni_{1-x}O$ 박막의 변색현상을 조사한 결과, 박막의 미세구조 발달에 의해 $Li^+$ 이온의 가역적 수용량이 증가하고, 결과적으로 전기변색 기능이 향상됨을 알 수 있엇다. 50 $^{\circ}C/O_2$ 하에서 얻어진 170 nm 두께의 $Li_{2x}Ni_{1-x}O$ 박막은 30 mC/$cm^2$의 $Li^+$ 이온 수용력과 함께 약 1.3의 흡광밀도(OD)를 나타내었다. Lithium nickel oxide ($Li_{2x}Ni_{1-x}O$) thin films have been prepared by the RF sputtering of lithiated nickel oxide target, where the film microstructure was controlled by the sputtering atmosphere $(Ar/O_2)$ and the substrate temperature ($T_s=50/230^{\circ}C$). From the transmission electron microscopic analysis, it is found that the most porous film with the grain size of $∼80\AA$ could be fabricated under the sputtering atmosphere of $P(O_2)=8{\times}10^2$ mbar with the $$T_s$=50^{\circ}C.$ In the optical and electrochemical studies, the$Li_{2x}Ni_{1-x}O$ films exhibit a significant electrochromic property in association with the lithium insertion/deinsertion process. The amount of charge insertion ($Q_i$) and the optical density (OD) variation depend on the crystallinity of the film as well as its thickness, and for the $Li_{2x}Ni_{1-x}O$ film (170 nm thickness) prepared under $O_2$ atmosphere and $T_s=50^{\circ}C$, the OD could be increased up to ∼1.3 by the charge insertion with $Q_i=30\;mC/cm^2.$

Natural dye-sensitized ZnO nano-particles as photo-catalysts in complete degradation of E. coli bacteria and their organic content

Zyoud, A.,Dwikat, M.,Al-Shakhshir, S.,Ateeq, S.,Shteiwi, J.,Zu'bi, A.,Helal, M.H.S.,Campet, G.,Park, D.,Kwon, H.,Kim, T.W.,Kharoof, M.,Shawahna, R.,Hilal, H.S. Elsevier Sequoia 2016 Journal of photochemistry and photobiology Chemist Vol.328 No.-

<P>This communication describes for the first time how nano-size particles, sensitized with natural dye molecules of anthocyanin, can be used as catalysts in photo-degradation of gram negative Escherichia coli bacteria in water. The naked ZnO nano-particles degraded up to 83% of the bacteria under solar simulator light, while the dye-sensitized particles increased the bacterial loss by similar to 10%. Solar simulator light includes about 5% of UV tail (shorter than 400 nm) which means that both UV and visible light (longer than 400 nm) radiations could be involved. When a cut-off filter was used, the naked ZnO caused only 40% bacterial loss, in accordance with earlier literature that described killing of bacteria with ZnO particles both in the dark and under light. With the cut-off filter, the sensitized ZnO particles caused higher than 90% bacterial loss, which confirms sensitization of the ZnO particles to visible light. Moreover, the results show that the catalyzed photo-degradation process causes mineralization of the bacteria and their organic internal components which leach out by killing. The catalyst can be recovered and reused losing similar to 10% of its activity each time due to mineralization of the dye molecules. However, catalyst activity can be totally regained by re-sensitizing it with the anthocyanin dye. The effects of different experimental conditions, such as reaction temperature, pH, bacterial concentration and catalyst amount together with nutrient broth and saline media, will be discussed together with the role of the sensitizer. (C) 2016 Elsevier B.V. All rights reserved.</P>

Enhanced PEC characteristics of pre-annealed CuS film electrodes by metalloporphyrin/polymer matrices

Zyoud, Ahed,AlKerm, Rana S.,Alkerm, Rola S.,Abdelhadi, Doa׳,H.,Park, DaeHoon,Helal, Mohammed H.S.,Campet, Guy,Muthaffar, Reham W.,Kwon, Hansang,Hilal, Hikmat S. North-Holland 2016 Solar Energy Materials and Solar Cells Vol. No.

<P><B>Abstract</B></P> <P>High conversion efficiency (<I>η</I>) values have been obtained from modified CuS film electrodes electrochemically deposited onto Glass/FTO. The modification involved pre-annealing the film followed by coating with tetra(-4-pyridyl)porphyrinato manganese (MnTPyP<SUP>+</SUP>) ions embedded inside a polyethylene (PE) matrix. The Glass/FTO/CuS/MnTPyP/PE electrodes exhibited enhanced photo-electrochemical (PEC) characteristics under solar simulated illumination (5.6mW/cm<SUP>−2</SUP>) in aqueous media, compared to the as-prepared Glass/FTO/CuS films which showed no PEC activity. Up to 17.4% efficiency and 85% fill factor (FF) values were obtained from the modified film electrodes. Such characteristics have not been widely known for metal chalcogenide based film electrodes before. Different pre-annealing temperatures were attempted and the 250°C temperature, followed by quenching, showed favorable results. Different aqueous redox couples were studied and the environmentally safe FeCl<SUB>2</SUB>/FeCl<SUB>3</SUB> aqueous system showed highest PEC characteristics. Effect of pre-annealing on film electrode characteristics is discussed. The MnTPyP/PE matrix behaves as charge transfer catalyst for the holes across the CuS film/liquid junction.</P> <P><B>Highlights</B></P> <P> <UL> <LI> CuS film electrodes were coated with metalloporphyrinato manganese(III)/polyethylene matrices. </LI> <LI> High PEC characteristics have been exhibited by the modified electrodes. </LI> <LI> Modification enhanced both film electrode stability and efficiency together. </LI> <LI> The matrix behaved as charge transfer catalyst for holes at the solid/liquid interface. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>Annealing CuS film electrodes at moderate temperatures (preferably at 250°C) affects CuS film morphology and spectral properties, and coating with metalloporphyrin/polymer matrices enhanced their PEC efficiency and stability.</P> <P>[DISPLAY OMISSION]</P>