Showing papers by "Jianming Lin published in 2011"
TL;DR: A quasi-solid-state supercapacitor was assembled by using alkaline polyvinyl alcohol and potassium iodide (PVA-KOH-KI) as gel electrolyte and activated carbons electrodes.
263 citations
TL;DR: In this paper, rare-earth doped oxide of Lu 2 O 3 :(Tm 3+, Yb 3+ ) is prepared and introduced into the TiO 2 film in the DSSC.
64 citations
TL;DR: A microporous hybrid polymer of poly(acrylic acid)-g-cetyltrimethylammonium bromide/polyaniline (PAA-g-CTAB/PANI) was synthesized by a two-step solution polymerization as discussed by the authors.
45 citations
TL;DR: Using blend heterojunction consisting of C60 derivatives [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) and poly(3-hexylthiophene) (P3HT) as charge carrier transferring medium to replace I3−/I− redox electrolyte, a novel flexible dye-sensitized solar cell (DSSC) is fabricated as mentioned in this paper.
Abstract: Using blend heterojunction consisting of C60 derivatives [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) and poly(3-hexylthiophene) (P3HT) as charge carrier transferring medium to replace I3−/I− redox electrolyte, a novel flexible dye-sensitized solar cell (DSSC) is fabricated. The characterization of infrared spectra and ultraviolet-visible spectra shows that the PCBM/P3HT heterojunction has not only the absorption in ultraviolet light for PCBM, but also the absorption in visible and near infrared light for P3HT, which widens the photoelectric response range for DSSC. The influence of PCBM/P3HT mass ratio on the performance of the solar cell is discussed. Under 100 mW cm−2 (AM 1.5) simulated solar irradiation, the flexible solar cell achieves a light-to-electric energy conversion efficiency of 1.43%, open circuit voltage of 0.87 V, short circuit current density of 3.0 mA cm−2 and fill factor of 0.54.
43 citations
TL;DR: An upconversion luminescence powder TiO2:(Er3+, Yb3+) is prepared by a hydrothermal method and used to fabricate dye-sensitized solar cell (DSSC).
Abstract: An upconversion luminescence powder TiO2:(Er3+, Yb3+) is prepared by a hydrothermal method and used to fabricate dye-sensitized solar cell (DSSC). The TiO2:(Er3+, Yb3+) powder undergoes upconversion luminescence, converting infrared light which the dye can not absorb into visible light with wavelengths of 510–700 nm which the dye can absorb, increasing the photocurrent of the DSSC. TiO2:(Er3+, Yb3+) also acts as a p-type dopant, heightening the Fermi level of the oxide film, which increases the photovoltage of the DSSC. The best performance of the DSSC is found when the ratio of TiO2/luminescence powder is 1/3 in the luminescence layer. Under simulated solar irradiation of 100 mW cm−2 (AM 1.5), the DSSC containing TiO2:(Er3+, Yb3+) doping achieves a light-to-electricity energy conversion efficiency of 7.28% compared with 6.41% for the undoped DSSC.
42 citations
TL;DR: Flexible and uniquely network-structured polyaniline (PANi) and polypyrrole (PPy) supported Pt and Ag catalysts were synthesized using eggshell membrane as a template and explored for the methanol oxidation reaction (MOR) for proton exchange membrane fuel cell (PEMFC) application as discussed by the authors.
Abstract: Flexible and uniquely network-structured polyaniline (PANi) and polypyrrole (PPy) supported Pt and Ag catalysts were synthesized using eggshell membrane as a template and explored for the methanol oxidation reaction (MOR) for proton exchange membrane fuel cell (PEMFC) application. The scanning electron microscopy observation showed a hierarchically ordered macroporous network of PANi and PPy. Due to the difference of polymer and metal essences, Pt was in the form of nanoparticles and Ag was in the form of nanofibers on the surfaces of PANi and nanoflakes on PPy. Energy dispersive X-ray spectra, thermal gravimetric analysis, Fourier transform infrared spectroscopy, X-ray diffraction patterns and X-ray photoelectron spectra were used to characterize the resultant catalysts. The results revealed that the prepared flexible catalysts had a Pt loading of 7.5 and 7.48 wt% in Pt/PANi and Pt/PPy, and a Ag loading of 11.3 and 5.78 wt% in Ag/PANi and Ag/PPy, respectively. The PANi network was in its crystalline structure, which was expected to provide very high conductivities and electrochemical properties. The cyclic voltammetric studies at room temperature showed an excellent electrocatalytic activity for MOR in acidic medium. The catalysts were also checked in the electro-oxidation of methanol at high temperatures, a much higher electrocatalytic activity at 200 °C than that at 50 °C and good stability made them potential candidates for high-temperature PEMFCs. Combined with the mechanical strength, it is believed that PANi-based catalysts are more useful in MOR applications. The excellent properties, alterable supports, simple preparation procedure and low cost allow these catalysts to be used in high-temperature PEMFCs and other fields.
38 citations
TL;DR: In this paper, high performance and homogeneous platinum nanoparticles are electrodeposited onto titanium (Ti) mesh to form counter electrodes for use in large-area flexible dye-sensitized solar cells (DSSCs).
31 citations
TL;DR: In this paper, a bifunctional nanocrystal TiO2 structure able to offer both light scattering and electron generating properties was prepared by a simple method of adding a basic NH3·H2O agent to an acidic nano-coated TiO 2 paste to form bigger aggregates.
Abstract: A bifunctional nanocrystal TiO2 structure able to offer both light scattering and electron generating properties was prepared by a simple method of adding a basic NH3·H2O agent to an acidic nanocrystal TiO2 paste to form bigger TiO2 nanocrystal aggregates. When used to prepare the second nanocrystal TiO2 layer in the photoelectrode, the photovoltaic performance of DSSCs were obviously enhanced, and the highest energy conversion efficiency attainable was 8.11%, which is much higher than that of a DSSC containing a single nanocrystal TiO2 layer prepared using the original acidic TiO2 paste (4.34%).
28 citations
TL;DR: Gd2O3:Eu3+ downconversion luminescent powder was prepared using the homogeneous precipitation method and its optical properties were analyzed and it was introduced into a dye-sensitized solar cell (DSSC).
Abstract: Gd2O3:Eu3+ downconversion luminescent powder was prepared using the homogeneous precipitation method. Its optical properties were analyzed and it was introduced into a dye-sensitized solar cell (DSSC). As a luminescence medium, Gd2O3:Eu3+ improved light harvesting via conversion luminescence and increased the photocurrent of the DSSC. As a p-type dopant insulating rare earth oxides form an energy barrier, and the Gd2O3:Eu3+ elevated the energy level of the oxide film and increased the photovoltage. The photoelectric conversion efficiency for a DSSC with Gd2O3:Eu3+ doping (6:100) reached 7.01%, which was 17.4% higher than the photoelectrical conversion efficiency of a DSSC without Gd2O3:Eu3+ doping.
28 citations
TL;DR: In this paper, a simple, versatile approach to the fabrication of high conducting multilayer films composed of alternating graphene (G) nanosheets and poly(sodium 4-styrenesulfonate) (PSS) using an electrostatic spin self-assembly technique was reported.
Abstract: This article reports a simple, versatile approach to the fabrication of high conducting multilayer films composed of alternating graphene (G) nanosheets and poly(sodium 4-styrenesulfonate) (PSS) using an electrostatic spin self-assembly technique. G nanosheets were prepared from natural graphite by oxidization, expansion, exfoliation, reduction and modification with cationic surfactant cetyltrimethylammonium bromide (C16TAB) and anionic surfactant sodium dodecyl sulfate (SDS). The growth process of the (PSS/G+/G−)n multilayer films was characterized by UV-vis spectroscopy. Absorbance plotted against the number of bilayers exhibited a linear dependence, indicating a progressive and uniform deposition process of the multilayer films. Higher rotation speeds (ω) can be used to fabricate thinner films, and the G content is in direct proportion to ω−1/2. The prepared (PSS/G+/G−)n multilayer films exhibit an attractive electrical conductivity in the range of 80–110 S cm−1. When the film thickness overcomes the effect of surface roughness and film morphology, a percolation effect is observed at the percolation threshold. The effects of the number of bilayers on the electrical properties of the ultrathin films are investigated in detail. The results show that the conductivity and percolation threshold can be controlled by adjusting the PSS/G+/G− ratio, rotation speed, and size of G nanosheets.
24 citations
TL;DR: In this paper, a TiO2 paste was prepared by mixing commercial TiO 2 (P25), ethanol, distilled water and a small amount of Ti (IV) tetraisopropoxide (TTIP), following by a hydrothermal treatment.
Abstract: A TiO2 paste was prepared by mixing commercial TiO2 (P25), ethanol, distilled water and a small amount of Ti (IV) tetraisopropoxide (TTIP), following by a hydrothermal treatment. Before hydrothermal treatment, a stirring for 48 h can prevent cracking TiO2 films. TTIP significantly promote the chemical connection between TiO2 particles and its adherence to the substrate, the TTIP amount of 6 mol% is suitable. UV irradiation can remove some impurities and water from the TiO2 film with an optimal time of 2 h. Transmission electron microscopy, X-ray diffraction, scanning electron microscopy and photovoltaic tests are characterized and measured. Short-circuit current density, open-circuit voltage, fill factor and photoelectric conversion efficiencies for the fabricated flexible dye-sensitized solar cell are 7.20 mA cm−2, 0.769 V, 0.686 and 3.84%, respectively, under irradiation with a simulated solar light of 100 mW cm−2.
TL;DR: In this article, a proton exchange membrane with a superabsorbent host polyacrylamide/polyethylene glycol interpenetrated polymer network (PAM/PEG IPN) was used as an anhydrous proton conductor.
Abstract: To elevate the operating temperature of proton exchange membranes (PEMs) to 200 °C under anhydrous conditions, in the current work, the protic ionic liquid, 1-methylimidazolium trifluoromethanesulfonate ([MIm][Tfo]), was used as an anhydrous proton conductor and integrated with a superabsorbent host polyacrylamide/polyethylene glycol interpenetrated polymer network (PAM/PEG IPN) by doping and adsorbing methods. The resultant membranes could be operated up to 200 °C under nonhumidified conditions, showing a proton conductivity of 17.02 and 10.37 mS cm−1 at 150 °C for [MIm][Tfo] doped and adsorbed PAM/PEG IPN membranes, respectively. Because of the intrinsic nature of the PAM/PEG IPN superabsorbent, the loaded [MIm][Tfo] could not leak from the PEM systems even under high temperatures and pressures. A percolation phenomenon was observed because of the formation of proton-conducting channels for proton transfer. The new PEM presented a maximum tensile strength of 12.4 MPa and elongation of 1068% and 10.0 MPa and 1594% for the membranes by doping and adsorbing methods, respectively. To increase the electrocatalytic activity and decrease the cost of the catalyst, we also developed a well-aligned low-Pt anode catalyst using a fir template, exhibiting high activity for methanol oxidation reaction. When the methanol gas was bubbled into [MIm][Tfo] around the anode catalyst parallel to its channels, the oxidation current density at 200 °C was 8.7 times larger than that at 25 °C, whereas it was 5.4 times larger at 200 °C than that at 25 °C perpendicular to its channels. The membranes and efficient catalysts are possible candidates for direct methanol fuel cells that operate at high temperature and anhydrous conditions. The use of superabsorbents opens up a new route to high-temperature PEMs.
TL;DR: In this paper, a flower-like microsphere Bi2WO6 with an average diameter of 2.5 μm was synthesized by a simple hydrothermal method in the presence of surfactant sodium dodecyl sulfate (SDS) or polyvinylpyrrolidone (PVP).
Abstract: The flower-like microsphere Bi2WO6 with an average diameter of 2.5 μm is synthesized by a simple hydrothermal method in the presence of surfactant sodium dodecyl sulfate (SDS) or polyvinylpyrrolidone (PVP). The crystalline phase, compositions, morphology, microstructure, surface area and band gap energy of the Bi2WO6 are characterized by X-ray diffraction, X-ray energy-dispersive spectrum, scanning electron microscopy, transmission electron microscopy and absorption spectra. It is found that surfactant has a significant influence on the microstructure and properties of the samples. The surfactant SDS enhances the surface area and photocatalytic activity of Bi2WO6, while the surfactant PVP has an opposite effect. Under Xe lamp irradiation, the Bi2WO6 sample prepared in the presence of SDS can degrade dye Rhodamine B (RhB) effectively.
TL;DR: In this paper, a quasi-solid state dye-sensitized solar cells (QS-DSSC) containing poly (methyl methacrylate-co-acrylonitrile) [P (MMA-co)-AN] gel electrolytes were fabricated.
Abstract: Quasi-solid state dye-sensitized solar cells (QS-DSSC) containing poly (methyl methacrylate-co-acrylonitrile) [P (MMA-co-AN)] gel electrolytes were fabricated. By tuning AN molar percentage in P (MMA-co-AN), the optimized polymeric gel electrolyte for fabricating QS-DSSC can be obtained. QS-DSSC containing polymeric gel electrolyte with 45 mol.% AN in P(MMA-co-AN) shows higher energy conversion efficiency than that of QS-DSSCs containing polymeric gel electrolytes with either pure PMMA or PAN. So it presents an effective way to improve the photovoltaic performance of QS-DSSC by tuning the components of polymeric gelling agent. Copyright © 2010 John Wiley & Sons, Ltd.
TL;DR: The excellent properties, low cost, facile preparation and good biocompatibility of the PANi microtube arrays set a bridge between proteins/enzymes and electrodes, providing analytical access to a large group of enzymes for a variety of biosensor applications.
Abstract: Polyaniline (PANi) microtube arrays were synthesized by a secondary-template (fir wood and ZnO microtube array) method and confirmed by scanning electron microscopy (SEM). High magnification SEM observation revealed that the PANi microtube arrays were formed by nanospheres and nanorods. X-Ray diffraction, Fourier transform infrared spectroscopy and cyclic voltammetry were used to characterize the resultant PANi microtube arrays which were subsequently used as electrodes for glucose oxidase (GO) immobilization and the detection of glucose. Compared with the traditional PANi powder electrode, the bioelectrocatalytic activation of GO immobilized PANi microtube array electrode toward the oxidation of glucose has been significantly enhanced. The excellent properties, low cost, facile preparation and good biocompatibility of the PANi microtube arrays set a bridge between proteins/enzymes and electrodes, providing analytical access to a large group of enzymes for a variety of biosensor applications.
TL;DR: A macroporous silver network was facilely synthesized using eggshell membrane as template and explored for methanol oxidation reaction, showing a significantly enhanced electrocatalytic ability compared with a traditional silver mirror electrode.
Abstract: A macroporous silver network was facilely synthesized using eggshell membrane as template and explored for methanol oxidation reaction, showing a significantly enhanced electrocatalytic ability compared with a traditional silver mirror electrode. The scanning electron microscopy observation showed a hierarchically ordered macroporous silver network because of the Ag+-protein binding. Energy dispersive X-ray spectrum, X-ray diffraction patterns and X-ray photoelectron spectra were used to characterize the resultant macroporous Ag network. The cyclic voltammetric studies at room temperature showed an excellent electrocatalytic activity for a methanol oxidation reaction in an acidic medium. The macroporous silver network was also checked in the electro-oxidation of methanol at high temperatures. A much higher electrocatalytic activity at 250 °C than that at 50 °C made them potential candidates for high-temperature proton exchange membrane fuel cells. The research opens a new insight to design low-cost, highly active and stable catalysts for methanol oxidation. The facile synthesis, excellent properties, alterable supports and low cost allow this material to be used in high-temperature direct methanol fuel cells.
TL;DR: In this paper, a hybrid solar cell based on blends of the semiconducting polymer poly(3-octylthiophene-2,5-diyl)(P3OT) and [6,6]-phenyl C61 butyric acid methyl (PCBM) coated titanium dioxide (TiO2) nanocrystal film was studied.
TL;DR: Using conducting polymers blend heterojunction consisting of C60 derivatives PCBM and poly (3-hexylthiophene) (P3HT), a novel flexible solar cell was fabricated in this article.
Abstract: [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) / poly (3-hexylthiophene) (P3HT) heterojunction has not only the absorption in ultraviolet light for PCBM, but also the absorption in visible light for P3HT, which widens the incident light harvest range, improving the photoelectrical response of hybrid solar cell effectively. Using conducting polymers blend heterojunction consisting of C60 derivatives PCBM and P3HT as charge carrier transferring medium to replace I
3
−
=I− redox electrolyte and dye, a novel flexible solar cell was fabricated in this study. The influence of PCBM/P3HT mass ratio on the photovoltaic performance of the solar cell was also studied. Under a simulated solar irradiation of 100mW·cm−2, the flexible solar cell achieved a light-to-electric energy conversion efficiency of 1.04%, an open circuit voltage of 0.86 V, short circuit current density of 2.6 mA·cm−2 and fill factor (FF) of 0.46.
TL;DR: In this article, a bi-functional nanocrystalline TiO 2 (nc-TiO 2 ) layer able to offer both light-scattering and electron generating properties was prepared with a simple method through adding the basic NH 3 ·H 2 O agent into an acid nc-Ti O 2 paste to form some big rod-like nc -TiO2 aggregates by the chemical sintering process.
TL;DR: In this paper, a polystyrenesulfonate (PEDOT:PSS)/carbon conductive paste was prepared and coated on a conducting FTO glass to construct counter electrode for polymer heterojunction dye-sensitized solar cells (DSSCs).
Abstract: A Poly (3, 4-ethylenedioxythiophene): polystyrenesulfonate (PEDOT:PSS)/carbon conductive paste was prepared and coated on a conducting FTO glass to construct counter electrode for polymer heterojunction dye-sensitized solar cells (DSSCs). The surface morphology, conductivity, sheet resistance, redox properties and photoelectric properties of carbon electrode were observed respectively by scanning electron microscopy, four-probe tester and CHI660D electrochemical measurement system. The experimental results showed that DSSCs had the best photoelectric properties for PEDOT:PSS/carbon counter electrode annealing at 80°C in vacuum conditions. Using [6, 6]-phenyl-C61-butyric acid methyl ester (PCBM)/poly (3-hexylthiophene) (P3HT) heterojunction to replace I3− =I− redox electrolyte, the overall energy conversion efficiency of the DSSCs with barrier layer reached 4.11% under irradiation of a simulated solar light with a intensity of 100mW·cm−1 (AM 1.5), which is higher 20% than that of the DSSCs with Pt counter electrode (3.42%). The excellent photoelectric properties, simple preparation procedure and low cost allow the PEDOT:PSS/carbon electrode to be a credible alternative used in DSSCs.
TL;DR: In this article, Oligomer ethylene glycol (O-EG) based electrolytes without volatile components were prepared and used in dye-sensitized solar cell (DSSC).
Abstract: Oligomer ethylene glycol (O-EG) based electrolytes without volatile components were prepared and used in dye-sensitized solar cell (DSSC). The characteristics such as viscosity, ionic conductivity, and ionic activation energy of O-EG based electrolytes including liquid, gel and solid states were investigated and compared. It is found that the gel and solid O-EG electrolytes have two Ea values with the changed phase state by going with the increased temperature, and they can increase the onset of applied voltage for generating dark current in DSSCs as from 0.222 V with liquid O-EG electrolyte to 0.420 V with gel and solid O-EG electrolytes, which results in the enhanced light-to-electricity conversion efficiency from 1.4% with liquid to 1.82% with gel and 1.86% with solid electrolytes. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
TL;DR: In this paper, a novel route to synthesize centimeter-scaled polypyrrole (PPy) fiber in the presence of oligo-polyacrylamide was reported.
Abstract: Abstract We first report a novel route to synthesize centimeter-scaled polypyrrole (PPy) fiber in the presence of oligo-polyacrylamide. The Fourier transform infrared and ultraviolet-visible spectra reveal that the fiber is in high conductive state. The PPy fibers have a uniform diameter of 300 μm, and length varying from several millimeters to 4 cm. The temperature dependence of electrical conductivity reveal that the transport properties of PPy fibers should be dominantly characterized by phonon-assisted hopping mechanism. Polymer-directed crystal growth may provide promising routes to rational synthesis of various ordered organic materials with complex form and structural specialization.