Herein,an FMS/CC composite was successfully fabricated by depositing FeMoS_(4)onto a pristine carbon fiber cloth(CC)substrate via a facile two-step hydrothermal method.The amorphous nature of the FMS/CC compos-ite end...Herein,an FMS/CC composite was successfully fabricated by depositing FeMoS_(4)onto a pristine carbon fiber cloth(CC)substrate via a facile two-step hydrothermal method.The amorphous nature of the FMS/CC compos-ite endows it with abundant catalytically active sites,thereby accelerating the reduction of I_(3)^(-).More importantly,the dye-sensitized solar cells(DSSCs)prepared by scraping it on flexible titanium mesh with low resistance had low series resistance(Rs).Electrochemical characterizations revealed that the DSSCs employing the FMS/CC counter electrode achieved a power conversion efficiency(PCE)of ca.9.51%(surpassing the ca.8.15%efficiency of the Pt counter electrode),open-circuit voltage(Voc)of ca.0.79 V,short-circuit current density(Jsc)of ca.18.31 mA·cm^(-2),and fill factor(FF)of ca.0.65.Moreover,after 100 times of cyclic voltammetry(CV)test,the CV curve remained unchanged,indicating the excellent stability of FMS/CC in the electrolyte containing I_(3)^(-)/I^(-).展开更多
Corn stover,an agricultural waste,was used to prepare nitrogen self-doped carbon quantum dots(CQDs)through a simple hydrothermal method with only water at near room temperature for the first time.The surface,electroch...Corn stover,an agricultural waste,was used to prepare nitrogen self-doped carbon quantum dots(CQDs)through a simple hydrothermal method with only water at near room temperature for the first time.The surface,electrochemical,and photovoltaic characteristics of CQDs doped TiO_(2)in dye-sensitized solar cells(DSSCs)were thoroughly and systematically examined.The average diameter of blue-fluorescence CQDs measured by a high-resolution transmission electron microscope(HR-TEM)was 4.63±0.87 nm,which consisted of polar functional groups.The highest occupied molecular orbital(HOMO)and lowest unoccupied molecular orbital(LUMO)energy of the biomass-derived CQDs,determined by the cyclic voltammetry(CV)test,were,−5.48 eV and−3.89 eV,respectively.The negative shift of flat band potential(Vfb)in CQDs incorporated photoanode implies the fermi level shifted upward.Experimental results revealed that the improved performance of DSSCs was due to charge transport enhancement and separation,which resulted in the improved energy level configuration between TiO_(2),CQDs,and electrolytes.In this regard,the CQDs serve as a mediator that enables charge carrier transport without hindrance.In this study,CQDs added to TiO_(2)+N719,increased short circuit current density(JSC)and power conversion efficiency(PCE)value by∼26.00%(10.13 to 12.69 mA/cm^(2))and 27.20%(4.78%to 6.08%),respectively.展开更多
Photocatalytic oxidation desulfurization has become a research hotspot in recent years because of mild reaction conditions, less energy consumption and high selectivity. In this paper, TiO2 was loaded onto SBA-15 mole...Photocatalytic oxidation desulfurization has become a research hotspot in recent years because of mild reaction conditions, less energy consumption and high selectivity. In this paper, TiO2 was loaded onto SBA-15 molecular sieves and sensitized with organic dyes(2, 9-dichloroquinacridone, DCQ) to extend its spectral response range from ultraviolet light to visible light. The catalyst DCQ-X%TiO2@SBA-15 was characterized by BET measurements, X-ray diffraction, Fourier transform infrared spectroscopy and Ultraviolet-visible diffuse reflection spectra, and then it was applied for photocatalytic oxidation desulfurization of gasoline. The effects of different catalytic systems, TiO2 concentration, catalyst dosage, and different model sulfur compounds on catalytic desulfurization performance were investigated. Experimental results show that DCQ-TiO2@SBA-15 has a better performance than the unsensitized TiO2@SBA-15, and the desulfurization rate can reach up to 96.1% in a reaction time of 90 min.展开更多
The photosensitive initiating system composed of 7-diethylamino-3-(2'-benzimidazolyl)coumarin dye (DEDC) and diphenyliodonium hexafluorophosphate (DIHP) which act as the sensitizer and the initiator respectively, ...The photosensitive initiating system composed of 7-diethylamino-3-(2'-benzimidazolyl)coumarin dye (DEDC) and diphenyliodonium hexafluorophosphate (DIHP) which act as the sensitizer and the initiator respectively, can be used to initiate the polymerization of methyl methacrylate (MMA). The results showed that when exposed to visible light, coumarin dye/iodonium salt undergoes quick electron transfer from DEDC to DIHP and free radicals are produced. The visible light photoinduced reaction between DEDC and DIHP is mainly through the excited singlet state of DEDC and thus it is a little sensitive to O-2. The influence of concentration of DEDC, DIHP and MMA on the rate of photopolymerization of MMA was also investigated.展开更多
Two organic dyes XSS1 and XS52 derivated from triarylamine and indoline are synthesized for dye-sensitized solar ceils （DSCs） employing cobalt and iodine redox shuttles. The effects of dye structure upon the photoph...Two organic dyes XSS1 and XS52 derivated from triarylamine and indoline are synthesized for dye-sensitized solar ceils （DSCs） employing cobalt and iodine redox shuttles. The effects of dye structure upon the photophysical, electro-chemical characteristics and cell perfor- mance are investigated. XS51 with four hexyloxyl groups on triarylamine performs better steric hindrance and an improvement of photovoltage. X852 provides higher short-circuit photocurrent density due to the strong electron-donating capability of indoline unit. The results from the redox electrolyte on cell performances indicate that the synthesized dyes are more suitable for tris（1,10-phenanthroline）cobalt（II/III） redox couple than I-/I3- redox couple in assembling DSCs. Application of X852 in the cobalt electrolyte yields a DSC with an overall power conversion efficiency of 6.58% under AM 1.5 （100 mW/cm2） irradiation.展开更多
o-Chloro-hexaarylbiimidazole (o-Cl-HABI) can be sensitized efficiently by the dyes 1-ethyl-3'-methyl thiacyanine bromide (C1), 3,3'-diethyl thiacarbocyanine iodide (C2), and cyclopentanone 2,5-bis[2-(1,3 -dihy...o-Chloro-hexaarylbiimidazole (o-Cl-HABI) can be sensitized efficiently by the dyes 1-ethyl-3'-methyl thiacyanine bromide (C1), 3,3'-diethyl thiacarbocyanine iodide (C2), and cyclopentanone 2,5-bis[2-(1,3 -dihydro-1,3,3-trimethyl-2H-indol-2-ylidene)ethylidene] (C3) through electron transfer proceses. When exposed to a xenon lamp (filtered by Pyrex glass), the photosensitive systems composed of o-Cl-HABI and the above dyes can produce free radicals which initiate the polymerization of MMA. The photopolymerization kinetics equation was obtained for the o-Cl-HABI/C2 system, R-p = K [C2](0.75)[o-Cl-HABI](0.44)[MTA](0.12)[MMA](1.0). A comparison of the influence of different dyes on the conversion of MMA photopolymerization was conducted.展开更多
The effect of chromium doping on the photo- voltaic efficiency of dye-sensitized solar cells （DSSCs） with anodized TiO2 nanotubes followed by an annealing process was investigated. Cr-doped TiO2 nanotubes （CrTNs） ...The effect of chromium doping on the photo- voltaic efficiency of dye-sensitized solar cells （DSSCs） with anodized TiO2 nanotubes followed by an annealing process was investigated. Cr-doped TiO2 nanotubes （CrTNs） with different amounts of chromium were obtained by anodizing of titanium foils in a single-step process using potassium chro- mate as the chromium source. Film features were investigated by scanning electron microscopy （SEM）, X-ray diffraction （XRD）, energy-dispersive X-ray spectroscopy （EDX）, and ultraviolet-visible （UV-Vis） spectroscopy. It is clearly seen that highly ordered TiO2 nanotubes are formed in an anodizing solution free of potassium chromate, and with a gradual increase in the potassium chromate concentration, these nanotube structures change to nanoporous and compact films without porosity. The photovoltaic efficiencies of fabricated DSSCs were characterized by a solar cell measurement sys- tem via the photocurrent-voltage （l-V） curves. It is found that the photovoltaic efficiency of DSSCs with CrTNsl sample is improved by more than three times compared to that of DSSCs with undoped TNs. The energy conversion efficiency increases from 1.05 % to 3.89 % by doping of chromium.展开更多
Modified TiO2 films have been prepared by combining commercial titania powders （Degussa P25） with sol-gel made by titanium chloride （Ti-sol）. The result shows that clusters are formed by nanoparticles and large po...Modified TiO2 films have been prepared by combining commercial titania powders （Degussa P25） with sol-gel made by titanium chloride （Ti-sol）. The result shows that clusters are formed by nanoparticles and large pores can be seen on the surface of the TiO2 films. The short circuit photocurrent density and photoelectric conversion efficiency of the solar cells are obviously enhanced compared with those without modification. The relationship between the photoelectric conversion efficiency and the amount of Ti-sol was investigated. With the addition of 30 wt% Ti-sol, the photoelectric conversion efficiency as high as 9.75% is achieved, increasing by 28.3% compared with the solar cells without modification.展开更多
TiO2 tri-layer structure films were modified by C-ions implantation for improving the photovoltaic perfor- mance of dye-sensitized solar cells （DSSCs）, in which the structure of TiOa changes from rutile to anatase a...TiO2 tri-layer structure films were modified by C-ions implantation for improving the photovoltaic perfor- mance of dye-sensitized solar cells （DSSCs）, in which the structure of TiOa changes from rutile to anatase and the sizes of TiOa particles increase. The optimal concentration of ions implantation for C-implanted cells is 1 ~ 1015 atom.cm-2, and the maximum conversion efficiency of 5.32 % is achieved （luminous intensity of 1 sun, light irradiance of AM1.SG）, which is 25.2 % higher than that of unimplanted cell. The significant improvement in conversion efficiency by carbon- ion implantation is contributed to reducing charge recombi- nation and enhancing the light-harvesting ability, as indicated from incident photon-to-collected electron conversion effi- ciency （IPCE） and ultraviolet-visible （UV-Vis） measure- ments. Furthermore, the charge carrier＇s lifetime in the tri- layer titania films is prolonged after carbon-ion implantations.展开更多
The ZnO-modified TiO2 electrode was prepared by adding Zn（CH3COO）2·2H2O to the TiO2 colloid during the sol-gel production process, and was used in dye-sensitized solar cells （DSCs）. The open circuit voltage ...The ZnO-modified TiO2 electrode was prepared by adding Zn（CH3COO）2·2H2O to the TiO2 colloid during the sol-gel production process, and was used in dye-sensitized solar cells （DSCs）. The open circuit voltage （Voc） and fill factor （if） of the cells were improved sig- nificantly. The performances of the ZnO-modified TiO2 electrode such as dark current, transient photocurrent, impedance, absorption spectra, and fiat band potential （Vfb） were investigated. It is found that the interface charge recombination impedance increases and Vfb shifts about 200 mV toward the cathodic potential. The effect mechanism of ZnO modification on the performance of DSCs may be that ZnO occupies the surface states of the TiO2 film.展开更多
Development of cost-effective and robust counter electrodes(CEs) is a persistent objective for highefficiency dye-sensitized solar cells(DSSCs). To achieve this goal, we present here the hydrothermal synthesis of well...Development of cost-effective and robust counter electrodes(CEs) is a persistent objective for highefficiency dye-sensitized solar cells(DSSCs). To achieve this goal, we present here the hydrothermal synthesis of well-aligned Ni Pt alloy CEs, which is templated by ZnO nanowires and nanosheets. The preliminary results demonstrate that Ni Pt alloy electrodes are featured by increased charge-transfer processes and electrocatalytic activity in comparison with expensive Pt CE, yielding power conversion efficiencies of 8.29% and 7.41% in corresponding DSSCs with Ni Pt nanowire and nanosheet alloy CEs, respectively. Additionally, the Ni Pt alloy CEs also display extraordinary dissolution-resistant ability when suffering longterm utilization in liquid-junction DSSCs.展开更多
With the aim of reducing series resistance and increasing dye loading,novel dye-sensitized solar cell architecture was designed with TiO2 nanoparticle-coated Ag nanowires array as the photoanode.Ag nanowire array was ...With the aim of reducing series resistance and increasing dye loading,novel dye-sensitized solar cell architecture was designed with TiO2 nanoparticle-coated Ag nanowires array as the photoanode.Ag nanowire array was prepared by anodic aluminum oxide (AAO) templateassisted electrochemical deposition route.Then,Ag nanowires were coated by TiO2 nanoparticles in hydrothermal process.The structures of the photoanode were characterized by field emission scanning electron microscopy (FESEM).Ag nanowires are covered by a layer of very fine nanoparticles with a diameter of less than 5 nm.X-ray diffraction (XRD) and selected-area electron diffraction (SAED) show that Ag nanowires have a strong preferred orientation in (220) direction and the TiO2 coating layer is a polycrystalline structure.With this photoanode,3.2 % conversion efficiency is achieved for the cell sensitized with N3 dye.展开更多
Dye-sensitized solar cells（DSSCs） have attracted significant attention as alternatives to conventional silicon-based solar cells owing to their low-cost production,facile fabrication,excellent stability and high pow...Dye-sensitized solar cells（DSSCs） have attracted significant attention as alternatives to conventional silicon-based solar cells owing to their low-cost production,facile fabrication,excellent stability and high power conversion efficiency（PCE）.The dye molecule is one of the key components in DSSCs since it significant influence on the PCE,charge separation,light-harvesting,as well as the device stability.Among various dyes,easily tunable phenothiazine-based dyes hold a large proportion and achieve impressive photovoltaic performances.This class of dyes not only has superiorly non-planar butterfly structure but also possesses excellent electron donating ability and large π conjugated system.This review summarized recent developments in the phenothiazine dyes,including small molecule phenothiazine dyes,polymer phenothiazine dyes and phenothiazine dyes for co-sensitization,especially focused on the developments and design concepts of small molecule phenothiazine dyes,as well as the correlation between molecular structures and the photovoltaic performances.展开更多
Titanium tetrachloride (TiCl4) treatment was employed to TiO2 coating deposited on fluoride-doped tin oxide (FTO) conducting glass and indium oxide doped tin oxide (ITO) conducting glass, respectively. The nano-crysta...Titanium tetrachloride (TiCl4) treatment was employed to TiO2 coating deposited on fluoride-doped tin oxide (FTO) conducting glass and indium oxide doped tin oxide (ITO) conducting glass, respectively. The nano-crystalline TiO2 coating was deposited using a composite powder composed of polyethylene glycol (PEG) and 25 nm TiO2 particles by vacuum cold spraying (VCS) process. A commercial N-719 dye was used to adsorb on the surface of TiO2 coating to prepare TiO2 electrode, which was applied to assemble dye-sensitized solar cell (DSC). The cell performance was measured under simulated solar light at an intensity of 100 mW·cm-2. Results show that with an FTO substrate the DSC composed of a VCS TiO2 electrode untreated by TiCl4 gives a short-circuit current density of 13.1 mA·cm-2 and an open circuit voltage of 0.60 V corresponding to an overall conversion efficiency of 4.4%. It is found that after TiCl4 treatment to the VCS TiO2 electrode with an FTO substrate, the short circuit current density of the cell increases by 31%, the open-circuit voltage increases by 60 mV and a higher conversion yield of 6.5% was obtained. However, when an ITO substrate is used to deposit TiO2 coating by VCS, after TiCl4 treatment, the conversion efficiency of the assembled cell reduces slightly due to corrosion of the conducting layer on the ITO glass by TiCl4.展开更多
The electroactive materials used in the counter electrode(CE)are of great concern as they influence the photovoltaic performances of dye-sensitized solar cells.The main functions of CE materials are collecting electro...The electroactive materials used in the counter electrode(CE)are of great concern as they influence the photovoltaic performances of dye-sensitized solar cells.The main functions of CE materials are collecting electrons from the external circuit and transferring them to the electrolyte and realizing the catalytic reduction of the redox species(I3^– or Co^3+)present in the electrolyte.The research hotspot of CE materials is seeking functional materials that display high efficiency,low cost,and good electrochemical stability and can substitute the benchmark platinum electrode.Chalcogen compounds of cobalt,nickel,and iron have been widely applied as CE materials and exhibit excellent electrocatalytic performances owing to their unique electrical properties,similar energies of adsorption of I atoms as platinum,excellent catalytic activities,and good chemical stabilities.In this review,we trace the developments and performances of chalcogen compounds of iron,cobalt,and nickel as CE materials and present the latest research directions for improving the electrocatalytic performances.We then highlight the optimization strategies for further improving their performances,such as fabrication of architectures,regulation of the components,synthesis of composites containing carbon materials,and elemental doping.展开更多
Highly homogeneous, well dispersed SiO_2@Au@TiO_2(SAT) microspheres decorated with Au nanoparticles(AuNPs) were prepared and incorporated into the photoanode with an optimized concentration gradientascent. The effects...Highly homogeneous, well dispersed SiO_2@Au@TiO_2(SAT) microspheres decorated with Au nanoparticles(AuNPs) were prepared and incorporated into the photoanode with an optimized concentration gradientascent. The effects of SAT microspheres and the gradient-ascent architecture on the light absorption and the photoelectric conversion efficiency(PCE) of the dye-sensitized solar cells(DSSCs) were investigated.Studies indicate that the introduction of SAT microspheres and the gradient-ascent architecture in the photoanode significantly enhance the light scattering and harvesting capability of the photoanode. The DSSC with the optimized SAT gradient-ascent photoanode has the maximum short circuit current density(J_(sc)) of 17.7 mA cm^(-2) and PCE of 7.75%, remarkably higher than those of the conventional DSSC by 23.7%and 28.0%, respectively. This significantly enhancement of the performance of the DSSC can be attributed to the excellent light reflection/scattering of SAT, the localized surface plasma resonance(LSPR) effect of AuNPs within the microspheres, and the gradient-ascent architecture of SAT microspheres inside the photoanode. This study demonstrates that the tri-synergies of the scattering of SAT microspheres, the LSPR of AuNPs and the gradient-ascent architecture can effectively improve the PCE of DSSC.展开更多
The micro-ring like structured zinc oxide(ZnO) film was deposited on SnO_2: F coated glass substrate by sol-gel dip-coating technique with 1.0 g polyethylene glycol(PEG) content. The surface morphology of micro-ring s...The micro-ring like structured zinc oxide(ZnO) film was deposited on SnO_2: F coated glass substrate by sol-gel dip-coating technique with 1.0 g polyethylene glycol(PEG) content. The surface morphology of micro-ring structured ZnO film has been confirmed by the scanning electron microscope. This ZnO film is used to fabricate the solar cell with the help of ruthenium based dye and carbon counter electrode. The photoelectric and incident photon-to-current conversion efficiency was 1.17% and 48.4%, respectively. The DSC results have been compared with ZnO films prepared without PEG contents.展开更多
Single-crystalline anatase TiO2nanorods have been prepared by solvothermal method using tetrabutylammonium hydroxide（TBAH） as a morphology controlling agent.The obtained TiO2nanorods are dominated by a large percent...Single-crystalline anatase TiO2nanorods have been prepared by solvothermal method using tetrabutylammonium hydroxide（TBAH） as a morphology controlling agent.The obtained TiO2nanorods are dominated by a large percentage of {010} facets.The power conversion efficiency of dye-sensitized solar cell（DSSC） based on anatase TiO2nanorods（8.66%） exhibits a significant improvement（35%） compared to that of P25 TiO2（5.66%）.The high performance of the anatase TiO2nanorods solar cell is ascribed to their large percent of exposed {010} facets as well as balancing their surface areas and sizes.展开更多
Dye-sensitized solar cell(DSC)consists a combination of several different materials:photoanodes with nanoparticulated semiconductors,sensitizers,electrolytes and counter electrodes(CEs).Each materials performs specifi...Dye-sensitized solar cell(DSC)consists a combination of several different materials:photoanodes with nanoparticulated semiconductors,sensitizers,electrolytes and counter electrodes(CEs).Each materials performs specific task for the conversion of solar energy into electricity.The main function of CE is to transfer electrons to the redox electrolyte and regenerate iodide ion.The work of CE is mainly focused on the studies of the kinetic performance and stability of the traditional CEs to improve the overall efficiency of DSC,seeking novel design concepts or new materials.In this review,the development and research progress of different CE materials and their electrochemical performance,and the problems are discussed.展开更多
A flexible counter electrode(CE) for dye-sensitized solar cells(DSCs) has been fabricated using a micro-porous polyvinylidene fluoride membrane as support media and sputtered Pt as the catalytic material.Non-conventio...A flexible counter electrode(CE) for dye-sensitized solar cells(DSCs) has been fabricated using a micro-porous polyvinylidene fluoride membrane as support media and sputtered Pt as the catalytic material.Non-conventional structure DSCs have been developed by the fabricated CEs. The Pt metal was sputtered onto one surface of the membrane as the catalytic material. DSCs were assembled by attaching the Ti O2 electrode to the membrane surface without Pt coating. The membrane was with cylindrical pore geometry. It served not only as a substrate for the CE but also as a spacer for the DSC. The fabricated DSC with the flexible membrane CE showed higher photocurrent density than the conventional sandwich devices based on chemically deposited Pt/FTO glass, achieving a photovoltaic conversion efficiency of 4.43%. The results provides useful information in investigation and development of stable, low-cost, simple-design, flexible and lightweight DSCs.展开更多
文摘Herein,an FMS/CC composite was successfully fabricated by depositing FeMoS_(4)onto a pristine carbon fiber cloth(CC)substrate via a facile two-step hydrothermal method.The amorphous nature of the FMS/CC compos-ite endows it with abundant catalytically active sites,thereby accelerating the reduction of I_(3)^(-).More importantly,the dye-sensitized solar cells(DSSCs)prepared by scraping it on flexible titanium mesh with low resistance had low series resistance(Rs).Electrochemical characterizations revealed that the DSSCs employing the FMS/CC counter electrode achieved a power conversion efficiency(PCE)of ca.9.51%(surpassing the ca.8.15%efficiency of the Pt counter electrode),open-circuit voltage(Voc)of ca.0.79 V,short-circuit current density(Jsc)of ca.18.31 mA·cm^(-2),and fill factor(FF)of ca.0.65.Moreover,after 100 times of cyclic voltammetry(CV)test,the CV curve remained unchanged,indicating the excellent stability of FMS/CC in the electrolyte containing I_(3)^(-)/I^(-).
基金the Department of Energy(DOE,Award Number:DE-FE0031997)for providing funds to support our research.
文摘Corn stover,an agricultural waste,was used to prepare nitrogen self-doped carbon quantum dots(CQDs)through a simple hydrothermal method with only water at near room temperature for the first time.The surface,electrochemical,and photovoltaic characteristics of CQDs doped TiO_(2)in dye-sensitized solar cells(DSSCs)were thoroughly and systematically examined.The average diameter of blue-fluorescence CQDs measured by a high-resolution transmission electron microscope(HR-TEM)was 4.63±0.87 nm,which consisted of polar functional groups.The highest occupied molecular orbital(HOMO)and lowest unoccupied molecular orbital(LUMO)energy of the biomass-derived CQDs,determined by the cyclic voltammetry(CV)test,were,−5.48 eV and−3.89 eV,respectively.The negative shift of flat band potential(Vfb)in CQDs incorporated photoanode implies the fermi level shifted upward.Experimental results revealed that the improved performance of DSSCs was due to charge transport enhancement and separation,which resulted in the improved energy level configuration between TiO_(2),CQDs,and electrolytes.In this regard,the CQDs serve as a mediator that enables charge carrier transport without hindrance.In this study,CQDs added to TiO_(2)+N719,increased short circuit current density(JSC)and power conversion efficiency(PCE)value by∼26.00%(10.13 to 12.69 mA/cm^(2))and 27.20%(4.78%to 6.08%),respectively.
基金This research was funded by National Natural Science Foundation of China (Grant No. 21676099)the Fundamental Research Funds for the Central Universities, South China University of Technology
文摘Photocatalytic oxidation desulfurization has become a research hotspot in recent years because of mild reaction conditions, less energy consumption and high selectivity. In this paper, TiO2 was loaded onto SBA-15 molecular sieves and sensitized with organic dyes(2, 9-dichloroquinacridone, DCQ) to extend its spectral response range from ultraviolet light to visible light. The catalyst DCQ-X%TiO2@SBA-15 was characterized by BET measurements, X-ray diffraction, Fourier transform infrared spectroscopy and Ultraviolet-visible diffuse reflection spectra, and then it was applied for photocatalytic oxidation desulfurization of gasoline. The effects of different catalytic systems, TiO2 concentration, catalyst dosage, and different model sulfur compounds on catalytic desulfurization performance were investigated. Experimental results show that DCQ-TiO2@SBA-15 has a better performance than the unsensitized TiO2@SBA-15, and the desulfurization rate can reach up to 96.1% in a reaction time of 90 min.
基金This work was supported by the National Natural Science Foundation of China (No. 59773011).
文摘The photosensitive initiating system composed of 7-diethylamino-3-(2'-benzimidazolyl)coumarin dye (DEDC) and diphenyliodonium hexafluorophosphate (DIHP) which act as the sensitizer and the initiator respectively, can be used to initiate the polymerization of methyl methacrylate (MMA). The results showed that when exposed to visible light, coumarin dye/iodonium salt undergoes quick electron transfer from DEDC to DIHP and free radicals are produced. The visible light photoinduced reaction between DEDC and DIHP is mainly through the excited singlet state of DEDC and thus it is a little sensitive to O-2. The influence of concentration of DEDC, DIHP and MMA on the rate of photopolymerization of MMA was also investigated.
文摘Two organic dyes XSS1 and XS52 derivated from triarylamine and indoline are synthesized for dye-sensitized solar ceils （DSCs） employing cobalt and iodine redox shuttles. The effects of dye structure upon the photophysical, electro-chemical characteristics and cell perfor- mance are investigated. XS51 with four hexyloxyl groups on triarylamine performs better steric hindrance and an improvement of photovoltage. X852 provides higher short-circuit photocurrent density due to the strong electron-donating capability of indoline unit. The results from the redox electrolyte on cell performances indicate that the synthesized dyes are more suitable for tris（1,10-phenanthroline）cobalt（II/III） redox couple than I-/I3- redox couple in assembling DSCs. Application of X852 in the cobalt electrolyte yields a DSC with an overall power conversion efficiency of 6.58% under AM 1.5 （100 mW/cm2） irradiation.
基金This project financially supported by National Natural Science Foundation of China (Project number 59973023)
文摘o-Chloro-hexaarylbiimidazole (o-Cl-HABI) can be sensitized efficiently by the dyes 1-ethyl-3'-methyl thiacyanine bromide (C1), 3,3'-diethyl thiacarbocyanine iodide (C2), and cyclopentanone 2,5-bis[2-(1,3 -dihydro-1,3,3-trimethyl-2H-indol-2-ylidene)ethylidene] (C3) through electron transfer proceses. When exposed to a xenon lamp (filtered by Pyrex glass), the photosensitive systems composed of o-Cl-HABI and the above dyes can produce free radicals which initiate the polymerization of MMA. The photopolymerization kinetics equation was obtained for the o-Cl-HABI/C2 system, R-p = K [C2](0.75)[o-Cl-HABI](0.44)[MTA](0.12)[MMA](1.0). A comparison of the influence of different dyes on the conversion of MMA photopolymerization was conducted.
基金the financial support from Iranian Nanotechnology Society and Isfahan University of Technology (IUT) Research Council
文摘The effect of chromium doping on the photo- voltaic efficiency of dye-sensitized solar cells （DSSCs） with anodized TiO2 nanotubes followed by an annealing process was investigated. Cr-doped TiO2 nanotubes （CrTNs） with different amounts of chromium were obtained by anodizing of titanium foils in a single-step process using potassium chro- mate as the chromium source. Film features were investigated by scanning electron microscopy （SEM）, X-ray diffraction （XRD）, energy-dispersive X-ray spectroscopy （EDX）, and ultraviolet-visible （UV-Vis） spectroscopy. It is clearly seen that highly ordered TiO2 nanotubes are formed in an anodizing solution free of potassium chromate, and with a gradual increase in the potassium chromate concentration, these nanotube structures change to nanoporous and compact films without porosity. The photovoltaic efficiencies of fabricated DSSCs were characterized by a solar cell measurement sys- tem via the photocurrent-voltage （l-V） curves. It is found that the photovoltaic efficiency of DSSCs with CrTNsl sample is improved by more than three times compared to that of DSSCs with undoped TNs. The energy conversion efficiency increases from 1.05 % to 3.89 % by doping of chromium.
文摘Modified TiO2 films have been prepared by combining commercial titania powders （Degussa P25） with sol-gel made by titanium chloride （Ti-sol）. The result shows that clusters are formed by nanoparticles and large pores can be seen on the surface of the TiO2 films. The short circuit photocurrent density and photoelectric conversion efficiency of the solar cells are obviously enhanced compared with those without modification. The relationship between the photoelectric conversion efficiency and the amount of Ti-sol was investigated. With the addition of 30 wt% Ti-sol, the photoelectric conversion efficiency as high as 9.75% is achieved, increasing by 28.3% compared with the solar cells without modification.
基金financially supported by the National Natural Science Foundation of China (No. 51202139)Shanghai Pujiang Program (No. 11PJ1403400)the Fundamental Research Funds for Central Universities (No. 2012LYB24)
文摘TiO2 tri-layer structure films were modified by C-ions implantation for improving the photovoltaic perfor- mance of dye-sensitized solar cells （DSSCs）, in which the structure of TiOa changes from rutile to anatase and the sizes of TiOa particles increase. The optimal concentration of ions implantation for C-implanted cells is 1 ~ 1015 atom.cm-2, and the maximum conversion efficiency of 5.32 % is achieved （luminous intensity of 1 sun, light irradiance of AM1.SG）, which is 25.2 % higher than that of unimplanted cell. The significant improvement in conversion efficiency by carbon- ion implantation is contributed to reducing charge recombi- nation and enhancing the light-harvesting ability, as indicated from incident photon-to-collected electron conversion effi- ciency （IPCE） and ultraviolet-visible （UV-Vis） measure- ments. Furthermore, the charge carrier＇s lifetime in the tri- layer titania films is prolonged after carbon-ion implantations.
基金supported by the Major State Basic Research Development Program of China (No.2006CB202605)the National Natural Science Foundation of China (No.50473055)
文摘The ZnO-modified TiO2 electrode was prepared by adding Zn（CH3COO）2·2H2O to the TiO2 colloid during the sol-gel production process, and was used in dye-sensitized solar cells （DSCs）. The open circuit voltage （Voc） and fill factor （if） of the cells were improved sig- nificantly. The performances of the ZnO-modified TiO2 electrode such as dark current, transient photocurrent, impedance, absorption spectra, and fiat band potential （Vfb） were investigated. It is found that the interface charge recombination impedance increases and Vfb shifts about 200 mV toward the cathodic potential. The effect mechanism of ZnO modification on the performance of DSCs may be that ZnO occupies the surface states of the TiO2 film.
基金financial supports from the National Natural Science Foundation of China(21503202,61604143,51362031)Shandong Provincial Natural Science Foundation(JQ201714)and Fundamental Research Funds for the Central Universities(201762018)
文摘Development of cost-effective and robust counter electrodes(CEs) is a persistent objective for highefficiency dye-sensitized solar cells(DSSCs). To achieve this goal, we present here the hydrothermal synthesis of well-aligned Ni Pt alloy CEs, which is templated by ZnO nanowires and nanosheets. The preliminary results demonstrate that Ni Pt alloy electrodes are featured by increased charge-transfer processes and electrocatalytic activity in comparison with expensive Pt CE, yielding power conversion efficiencies of 8.29% and 7.41% in corresponding DSSCs with Ni Pt nanowire and nanosheet alloy CEs, respectively. Additionally, the Ni Pt alloy CEs also display extraordinary dissolution-resistant ability when suffering longterm utilization in liquid-junction DSSCs.
基金financially supported by the National Natural Science Foundation of China(No.51301041)
文摘With the aim of reducing series resistance and increasing dye loading,novel dye-sensitized solar cell architecture was designed with TiO2 nanoparticle-coated Ag nanowires array as the photoanode.Ag nanowire array was prepared by anodic aluminum oxide (AAO) templateassisted electrochemical deposition route.Then,Ag nanowires were coated by TiO2 nanoparticles in hydrothermal process.The structures of the photoanode were characterized by field emission scanning electron microscopy (FESEM).Ag nanowires are covered by a layer of very fine nanoparticles with a diameter of less than 5 nm.X-ray diffraction (XRD) and selected-area electron diffraction (SAED) show that Ag nanowires have a strong preferred orientation in (220) direction and the TiO2 coating layer is a polycrystalline structure.With this photoanode,3.2 % conversion efficiency is achieved for the cell sensitized with N3 dye.
基金the National Natural Science Foundation of China(Nos.21572030,21272033,21402023)Fundamental Research Funds for the Central Universities(No.ZYGX2014J026)for financial support
文摘Dye-sensitized solar cells（DSSCs） have attracted significant attention as alternatives to conventional silicon-based solar cells owing to their low-cost production,facile fabrication,excellent stability and high power conversion efficiency（PCE）.The dye molecule is one of the key components in DSSCs since it significant influence on the PCE,charge separation,light-harvesting,as well as the device stability.Among various dyes,easily tunable phenothiazine-based dyes hold a large proportion and achieve impressive photovoltaic performances.This class of dyes not only has superiorly non-planar butterfly structure but also possesses excellent electron donating ability and large π conjugated system.This review summarized recent developments in the phenothiazine dyes,including small molecule phenothiazine dyes,polymer phenothiazine dyes and phenothiazine dyes for co-sensitization,especially focused on the developments and design concepts of small molecule phenothiazine dyes,as well as the correlation between molecular structures and the photovoltaic performances.
文摘Titanium tetrachloride (TiCl4) treatment was employed to TiO2 coating deposited on fluoride-doped tin oxide (FTO) conducting glass and indium oxide doped tin oxide (ITO) conducting glass, respectively. The nano-crystalline TiO2 coating was deposited using a composite powder composed of polyethylene glycol (PEG) and 25 nm TiO2 particles by vacuum cold spraying (VCS) process. A commercial N-719 dye was used to adsorb on the surface of TiO2 coating to prepare TiO2 electrode, which was applied to assemble dye-sensitized solar cell (DSC). The cell performance was measured under simulated solar light at an intensity of 100 mW·cm-2. Results show that with an FTO substrate the DSC composed of a VCS TiO2 electrode untreated by TiCl4 gives a short-circuit current density of 13.1 mA·cm-2 and an open circuit voltage of 0.60 V corresponding to an overall conversion efficiency of 4.4%. It is found that after TiCl4 treatment to the VCS TiO2 electrode with an FTO substrate, the short circuit current density of the cell increases by 31%, the open-circuit voltage increases by 60 mV and a higher conversion yield of 6.5% was obtained. However, when an ITO substrate is used to deposit TiO2 coating by VCS, after TiCl4 treatment, the conversion efficiency of the assembled cell reduces slightly due to corrosion of the conducting layer on the ITO glass by TiCl4.
基金supported by the National Science Fund for Distinguished Young Scholars(21425729)from the National Natural Science Foundation of Chinathe National Special S&T Project on Water Pollution Control and Treatment(2017ZX07107002)+1 种基金China Postdoctoral Science Foundation(2018M640209)the Tianjin Science and Technology Support Key Projects(18YFZCSF00500)~~
文摘The electroactive materials used in the counter electrode(CE)are of great concern as they influence the photovoltaic performances of dye-sensitized solar cells.The main functions of CE materials are collecting electrons from the external circuit and transferring them to the electrolyte and realizing the catalytic reduction of the redox species(I3^– or Co^3+)present in the electrolyte.The research hotspot of CE materials is seeking functional materials that display high efficiency,low cost,and good electrochemical stability and can substitute the benchmark platinum electrode.Chalcogen compounds of cobalt,nickel,and iron have been widely applied as CE materials and exhibit excellent electrocatalytic performances owing to their unique electrical properties,similar energies of adsorption of I atoms as platinum,excellent catalytic activities,and good chemical stabilities.In this review,we trace the developments and performances of chalcogen compounds of iron,cobalt,and nickel as CE materials and present the latest research directions for improving the electrocatalytic performances.We then highlight the optimization strategies for further improving their performances,such as fabrication of architectures,regulation of the components,synthesis of composites containing carbon materials,and elemental doping.
基金supported financially by the National Natural Science Foundation of China (Nos.51572102,11504101,11604089 and 11364018)
文摘Highly homogeneous, well dispersed SiO_2@Au@TiO_2(SAT) microspheres decorated with Au nanoparticles(AuNPs) were prepared and incorporated into the photoanode with an optimized concentration gradientascent. The effects of SAT microspheres and the gradient-ascent architecture on the light absorption and the photoelectric conversion efficiency(PCE) of the dye-sensitized solar cells(DSSCs) were investigated.Studies indicate that the introduction of SAT microspheres and the gradient-ascent architecture in the photoanode significantly enhance the light scattering and harvesting capability of the photoanode. The DSSC with the optimized SAT gradient-ascent photoanode has the maximum short circuit current density(J_(sc)) of 17.7 mA cm^(-2) and PCE of 7.75%, remarkably higher than those of the conventional DSSC by 23.7%and 28.0%, respectively. This significantly enhancement of the performance of the DSSC can be attributed to the excellent light reflection/scattering of SAT, the localized surface plasma resonance(LSPR) effect of AuNPs within the microspheres, and the gradient-ascent architecture of SAT microspheres inside the photoanode. This study demonstrates that the tri-synergies of the scattering of SAT microspheres, the LSPR of AuNPs and the gradient-ascent architecture can effectively improve the PCE of DSSC.
基金the Ministry of EducationCulture,Sports,Science and Technology,Japan for financial support
文摘The micro-ring like structured zinc oxide(ZnO) film was deposited on SnO_2: F coated glass substrate by sol-gel dip-coating technique with 1.0 g polyethylene glycol(PEG) content. The surface morphology of micro-ring structured ZnO film has been confirmed by the scanning electron microscope. This ZnO film is used to fabricate the solar cell with the help of ruthenium based dye and carbon counter electrode. The photoelectric and incident photon-to-current conversion efficiency was 1.17% and 48.4%, respectively. The DSC results have been compared with ZnO films prepared without PEG contents.
基金the financial support of the project from the National Natural Science Foundation of China(No.51202139)the Specialized Research Fund for the Doctoral Program of Higher education(No.20123108120022)+2 种基金the Natural Science Foundation of Shanghai(Nos. 12ZR1443900 and 14ZR1416400)the Special Research Foundation for Training and Selecting Outstanding Young Teachers of Universities in Shanghai(No.ZZSD12041)the Innovation Foundation of Shanghai University
文摘Single-crystalline anatase TiO2nanorods have been prepared by solvothermal method using tetrabutylammonium hydroxide（TBAH） as a morphology controlling agent.The obtained TiO2nanorods are dominated by a large percentage of {010} facets.The power conversion efficiency of dye-sensitized solar cell（DSSC） based on anatase TiO2nanorods（8.66%） exhibits a significant improvement（35%） compared to that of P25 TiO2（5.66%）.The high performance of the anatase TiO2nanorods solar cell is ascribed to their large percent of exposed {010} facets as well as balancing their surface areas and sizes.
基金the support of the National Natural Science Foundation of China under grant No.20673141the National Basic Research Program of China(973 Program)under grant No.2006CB202606the National High Technology Research and Development Program(863 Program)under grant No.2006AA03Z341 and the 100-Talents Project of Chinese Academy of Sciences.
文摘Dye-sensitized solar cell(DSC)consists a combination of several different materials:photoanodes with nanoparticulated semiconductors,sensitizers,electrolytes and counter electrodes(CEs).Each materials performs specific task for the conversion of solar energy into electricity.The main function of CE is to transfer electrons to the redox electrolyte and regenerate iodide ion.The work of CE is mainly focused on the studies of the kinetic performance and stability of the traditional CEs to improve the overall efficiency of DSC,seeking novel design concepts or new materials.In this review,the development and research progress of different CE materials and their electrochemical performance,and the problems are discussed.
基金supported by National Natural Science Foundation of China(No.10774046)Shanghai Municipal Science&Technology Committee(No.09JC1404600+1 种基金No.0852nm06100 and No.08230705400)Singapore Ministry of Education innovation fund(MOE IF Funding MOE2008-IF-1-016)
文摘A flexible counter electrode(CE) for dye-sensitized solar cells(DSCs) has been fabricated using a micro-porous polyvinylidene fluoride membrane as support media and sputtered Pt as the catalytic material.Non-conventional structure DSCs have been developed by the fabricated CEs. The Pt metal was sputtered onto one surface of the membrane as the catalytic material. DSCs were assembled by attaching the Ti O2 electrode to the membrane surface without Pt coating. The membrane was with cylindrical pore geometry. It served not only as a substrate for the CE but also as a spacer for the DSC. The fabricated DSC with the flexible membrane CE showed higher photocurrent density than the conventional sandwich devices based on chemically deposited Pt/FTO glass, achieving a photovoltaic conversion efficiency of 4.43%. The results provides useful information in investigation and development of stable, low-cost, simple-design, flexible and lightweight DSCs.
