A new type of dye-sensitized nanocrystalline solid state photovoltaic cell based on the wide band gap n-TiO2/p-CuI heterojunction was fabricated. Tetra-carboxyphenyl porphyrine (TPP-(COOH)(4)), squarylium cyanine deri...A new type of dye-sensitized nanocrystalline solid state photovoltaic cell based on the wide band gap n-TiO2/p-CuI heterojunction was fabricated. Tetra-carboxyphenyl porphyrine (TPP-(COOH)(4)), squarylium cyanine derivative (SQ-(CH2),(SO3Py+)-Py-.) and ruthenium bipyridyl complex (RuL2(NCS)(2)) were used as photosensitizers. Larger photocurrents and photovoltages were shown in the cell sensitized by ruthenium bipyridyl complex and can be further increased by intercalation of a TiO2 thin underlayer.展开更多
Titania is one kind of important materials, which has been extensively investigated because of its unique electronic and optical properties. Research efforts have largely focused on the optimization of the dye,but rec...Titania is one kind of important materials, which has been extensively investigated because of its unique electronic and optical properties. Research efforts have largely focused on the optimization of the dye,but recently the titania nanostructures electrode itself has attracted more attention. It has been shown that particle size, shape, crystallinity, surface morphology, and chemistry of the TiO_2 material are key parameters which should be controlled for optimized performance of the solar cell. Titania can be found in different shape of nanostructures including mesoporous, nanotube, nanowire, and nanorod structures. The present article reviews the structural, synthesis, electronic, and optical properties of TiO_2 nanostructures for dye sensitized solar cells.展开更多
Composite nanoporous electrode SnO2/TiO2 was fabricated for the dye sensitized solar cell (DSSC) with N3 (Cis-Ru). After introducing of TiO2, the open-circuit photovoltage (Voc) was higher than that of the pure SnO2 ...Composite nanoporous electrode SnO2/TiO2 was fabricated for the dye sensitized solar cell (DSSC) with N3 (Cis-Ru). After introducing of TiO2, the open-circuit photovoltage (Voc) was higher than that of the pure SnO2 electrode, while short-circuit photocurrent (Isc) was varied with the ratio of the TiO2. Appropriate content of the TiO2 can be beneficial to the efficiency of the solar cell, and it gives negative impact on the composite electrode when the content of TiO2 is higher.展开更多
A series of new metal-free organic dyes that contain donors with triphenylamine or its derivatives and tetrazole-based acceptors were synthesized and characterized by photophysical, electrochemical, and the- oretical ...A series of new metal-free organic dyes that contain donors with triphenylamine or its derivatives and tetrazole-based acceptors were synthesized and characterized by photophysical, electrochemical, and the- oretical computational methods. They were applied in nanocrystalline TiO2 solar cells (DSSCs). It is found that the introduction of diphenylamine units as antennas in the as-synthesized dyes could improve photo- voltaic performance compared with phenothiazine and carbazole units as antennas in DSSCs. The dye with (2H-tetrazol-5-yl) acrylonitrile electron acceptor also displayed the highest solar-to-electrical energy conver- sion efficiency.展开更多
The photoinitiating system composed of 1-ethyl-3'-methylthiacyanine bro-mide (C-I), 2-chlorohexaarylbiimidazole (o-Cl-HABI) and 3-mercapto-4-methyl-4H-1, 2, 4-triazole (MTA), which act as sensitizer, initiator and...The photoinitiating system composed of 1-ethyl-3'-methylthiacyanine bro-mide (C-I), 2-chlorohexaarylbiimidazole (o-Cl-HABI) and 3-mercapto-4-methyl-4H-1, 2, 4-triazole (MTA), which act as sensitizer, initiator and hydrogen-donor respectively, can beused to initiate the polymerization of methyl methacrylate (MMA). The kinetic study wascarried out in trichloromathane solution at 30℃ by using dilatometry. The relation be-tween the polymerization rate and the concentrations of C-I, o-Cl-HABI, MTA and MMAwas studied.展开更多
Although Bi_(2)Mo O_(6)(BMO) has recently received extensive attention, its visible-light photocatalytic activity remains poor due to its limited photoresponse range and low charge separation efficiency. In this work,...Although Bi_(2)Mo O_(6)(BMO) has recently received extensive attention, its visible-light photocatalytic activity remains poor due to its limited photoresponse range and low charge separation efficiency. In this work, a series of visible-light-driven Y^(3+)-doped BMO(Y-BMO) photocatalysts were synthesized via a hydrothermal method. Degradation experiments on Rhodamine B and Congo red organic pollutants revealed that the optimal degradation rates of Y-BMO were 4.3 and 5.3 times those of pure BMO, respectively. The degradation efficiency of Y-BMO did not significantly decrease after four cycle experiments. As a result of Y^(3+)doping, the crystal structure of BMO changed from a thick layer structure to a thin flower-like structure with an increased specific surface area. X-ray photoelectron spectroscopy showed the presence of highintensity peaks for the O 1s orbital at 531.01 and 530.06 eV, confirming the formation of oxygen vacancies in Y-BMO. Photoluminescence(PL) and electrochemical impedance spectroscopy measurements revealed that the PL intensity and interface resistances of composites decreased significantly, indicating reduced electron–hole pair recombination. This work provides an effective way to prepare high-efficiency Bibased photocatalysts by doping rare earth metal ions for improved photocatalytic performance.展开更多
Lanthanide-doped biocompatible nanoparticles have promising applications in near-infrared second region imaging due to their high chemical stability,enhanced photostability and sharp emission bandwidth.However,the wea...Lanthanide-doped biocompatible nanoparticles have promising applications in near-infrared second region imaging due to their high chemical stability,enhanced photostability and sharp emission bandwidth.However,the weak light absorption capacity limits the application of rare-earth nanoparticles(RENPs) for bioimaging.We prepared a coumarin-derived dye sensitized NaYGdF4:Yb,Er nanoparticle probe,in which the organic dye enhances photon absorption through the sensitization process,improving the luminescence efficiency of the rare earth particles near 1000 and 1500 nm.In addition,good water solubility and stability of the probe are imparted by coating the particles with amphiphilic polymers distearoyl phosphatidylethanolamine-polyethylene glycol(DSPE-PEG) and polyacrylic acid.This composite probe with good biocompatibility and NIR Ⅱ luminescence properties can be used for vascular imaging,providing a tool for the detection of hematologic-related diseases.展开更多
TiO_(2) nanoparticles(NPs)in the size of-25 nm,namely P25,are very common material as the electron collecting layer in dye-sensitized solar cells(DSsCs).However,the light-scattering improvement of TiO2 NP photoelectro...TiO_(2) nanoparticles(NPs)in the size of-25 nm,namely P25,are very common material as the electron collecting layer in dye-sensitized solar cells(DSsCs).However,the light-scattering improvement of TiO2 NP photoelectrodes is stll a challenge.Here,we built TiO2 cavities on the top of the TiO2 NP layer by using carbonaceous microspheres as the template,forming the TiO_(2) cavity/nanoparticle(C/NP)photoelectrode for the application in DSSCs.The cavity amount in the TiO_(2) C/NP photoelectrode was controlled by adjusting the weight ratio of carbonaceous microspheres.SEM results confirm the successful formation of the double-layered TiO_(2) C/NP electrode.J-V tests show that the optimized TiO_(2) C/NP electrode prepared with 25 wt.%carbonaceous microspheres contributes to remarkable improvement of the short-circuit current density(Jsc)and the power conversion efficiency(PcE).The best photovoltaic performance solar cell with the PCE of 9.08%is achieved with the optimized TiO_(2) C/NP photoelectrode,which is over 98% higher than that of the TiO_(2) NP photoelectrode.Further investigations of UV-vis DRS,IPCE,OCVD,and EIS demonstrate that the competition between light scattering effect and charges recombination in this TiO_(2) C/NP photoelectrode is responsiblefor the PCE enhancement.展开更多
To develop efficient sensitizers for dye-sensitized solar cells(DSSCs),we recently reported doubly concerted companion(DCC)dye XW83 with a wrapped porphyrin sub-dye unit linked to an organic sub-dye unit through a fle...To develop efficient sensitizers for dye-sensitized solar cells(DSSCs),we recently reported doubly concerted companion(DCC)dye XW83 with a wrapped porphyrin sub-dye unit linked to an organic sub-dye unit through a flexible chain,which exhibits panchromatic absorption and excellent anti-aggregation ability.To further improve the absorption,we herein report XW87 and XW88 by inserting an ethynyl group into the organic sub-dye unit of XW83 near the donor and acceptor,respectively.For the corresponding organic dyes Z3 and Z4,the introduced ethynyl group improves their absorption,but induces aggravated charge recombination,leading to lowered power conversion efficiencies(PCEs).Similar to the organic dyes,the introduced ethynyl group improves the absorption of DCC dyes XW87 and XW88 as well.In addition,the ethynyl group near the acceptor of the organic sub-dye unit can be well protected by the long wrapping chains from the porphyrin unit.As a result,XW88 affords the highest JSC(21.84 mA/cm^(2)),V_(OC)(782 mV)and PCE(12.2%)among the DCC dyes.These results provide an effective method for developing efficient DSSC dyes by inserting an ethynyl group at a suitable position of a DCC dye.展开更多
Developing low-energy input route for conversion of methane(CH_(4))to value-added methanol(CH_(3)OH)at room temperature is important in environment and industry.Bonding in electron donor-acceptor hybrid can potentiall...Developing low-energy input route for conversion of methane(CH_(4))to value-added methanol(CH_(3)OH)at room temperature is important in environment and industry.Bonding in electron donor-acceptor hybrid can potentially promote charge transfer and photocatalytic efficiency of CH_(4) conversion.Herein,bonding in electron donor rhodamine B(RhB)-acceptor(TiO_(2))hybrid(RhB/TiO_(2))significantly promotes the selectivity of photocatalytic oxidation of CH4 to CH3OH and utilization of visible light(low-energy photons)at ambient condition.Even under green light irradiation(λ=550 nm),the noble-metal-free RhB/TiO_(2) hybrid synthesized presents enhanced oxidation of CH4 to CH_(3)OH with a generation rate of 143µmol·g^(−1)·h^(−1) and selectivity of 94%.This work demonstrates the possibility and feasibility of noble-metal-free catalysts for activating CH4 under visible light at room temperature.展开更多
Light utilization is one of the key factors for the improvement of photocatalytic perfo rmance.He rein,we design C-TiO_(2) hollow nanoshells with strong Mie resonance for enhanced photocatalytic hydrogen evolution in ...Light utilization is one of the key factors for the improvement of photocatalytic perfo rmance.He rein,we design C-TiO_(2) hollow nanoshells with strong Mie resonance for enhanced photocatalytic hydrogen evolution in a dye-sensitized system under visible light irradiation(λ≥420 nm).By tuning the inner diameters of hollow nanoshells,the Mie resonance in hollow nanoshells is adjusted for better excitation of dye molecules,which thus greatly enhances the light utilization in visible light region.This work shows the potential of Mie resonance in nanoshells can be an alternative strategy to increase the light utilization for photocatalysis.展开更多
The pure TiO2 and Fe salts [Fe(C2O4)3,5H2O]-doped TiO2 electrodes were prepared by the hydrothermal method. The pure TiO2 or Fe-doped TiO2 slurry was coated onto the fluorine-doped tin oxide glass substrate by the D...The pure TiO2 and Fe salts [Fe(C2O4)3,5H2O]-doped TiO2 electrodes were prepared by the hydrothermal method. The pure TiO2 or Fe-doped TiO2 slurry was coated onto the fluorine-doped tin oxide glass substrate by the Doctor Blade method and then sintered at 450 ℃. The Mott-Schottks, plot indicates that the fiat band potential of TiO2 was shifted positively after Fe-doped TiO2. The positive shift of the fiat band potential improves the driving force of injected electrons from the LUMO of the dye to the conduction band of TiO2. This study shows that photovoltaic efficiency increased by 22.9% from 6.07% to 7.46% compared to pure TiO2, and the fill factors increased from 0.53 to 0.63.展开更多
Solution processible photovoltaics(PV)are poised to play an important role in scalable manufacturing of low-cost solar cells.Electrospray is uniquely suited for fabricating PVs due to its several desirable characteris...Solution processible photovoltaics(PV)are poised to play an important role in scalable manufacturing of low-cost solar cells.Electrospray is uniquely suited for fabricating PVs due to its several desirable characteristics of an ideal manufacturing process such as compatibility with roll-to-roll production processes,tunability and uniformity of droplet size,capability of operating at atmospheric pressure,and negligible material waste and nano structures.This review begins with an introduction of the fundamentals and unique properties of electrospray.We put emphasis on the evaporation time and residence time that jointly affect the deposition outcome.Then we review the efforts of electrospray printing polymer solar cells,perovskite solar cells,and dye sensitized solar cells.Collectively,these results demonstrate the advantages of electrospray for solution processed PV.Electrospray has also exhibited the capability of producing uniform films as well as nanostructured and even multiscale films.So far,the electrospray has been found to improve active layer morphology,and create devices with efficiencies comparable with that of spin-coating.Finally,we discuss challenges and research opportunities that enable electrospray to become a mainstream technique for industrial scale production.展开更多
For better performance of dye sensitized solar cells (DSSCs), a bilayer structured electrode was constructed by employing a mesoporous anatase TiO2 overlayer above a commercial P25 TiO2 nanoparticles underlayer. The...For better performance of dye sensitized solar cells (DSSCs), a bilayer structured electrode was constructed by employing a mesoporous anatase TiO2 overlayer above a commercial P25 TiO2 nanoparticles underlayer. The mesoporous anatase TiO2, prepared through a facile surfactant-assisted sol-gel process, possessed large pore size and well inter-connected network structure, both beneficial for dye adsorption and electron transfer. The dye adsorption capability of the mesoporous TiO2 was nearly twice that of the P25 counterpart. In the electrode, the mesoporous TiO2 film enhanced both dye adsorption and lightharvest, to increase photocurrent (Jsc) from 12.32 to 14.78 mA/cm^2. Compared to the single P25 TiO2 film, the synergy of the mesoporous TiO2 and the P25 TiO2 nanoparticle films in the electrode resulted in a 24% improvement in light-to-electricity conversion efficiency (η). This bilayered electrode provides an alternative approach for further developing a photovoltaic device with better cell performance.展开更多
TiO2 nanotube(NT) was firstly prepared on titanium foil by an electrochemical anodization method, and then modified via subsequent deposition of a layer of SrAl2O4:Eu2+ phosphor embedded within TiO2 nanoparticles to f...TiO2 nanotube(NT) was firstly prepared on titanium foil by an electrochemical anodization method, and then modified via subsequent deposition of a layer of SrAl2O4:Eu2+ phosphor embedded within TiO2 nanoparticles to fabricate photoanodes of dye–sensitized solar cells(DSSCs). The effect of doping down–conversion Sr Al2O4:Eu2+ phosphor in DSSCs was investigated. SrAl2O4:Eu2+ can effectively convert ultraviolet light to visible light within the range of the dye commonly used in DSSC to increase the photocurrent of DSSC, and enhance the open–circuit voltage by a p–type doping effect. When the ratio of Sr Al2O4:Eu2+ in the doping layer is optimized to be 1wt.%, the photoelectric conversion efficiency of the DSSC reaches 3.09%, which is increased by 38.6%, compared to that of the DSSC without Sr Al2O4:Eu2+ doping.展开更多
Sulfuric acid-treated poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)/less-defective reduced graphene oxide (ST-PEDOT:PSS/L-rGO) composite films were prepared via a solution-processing route and used a...Sulfuric acid-treated poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)/less-defective reduced graphene oxide (ST-PEDOT:PSS/L-rGO) composite films were prepared via a solution-processing route and used as the counter electrodes of dye sensitized solar cells (DSSCs). These platinum (Pt)- and transparent conductive oxide (TCO)-free counter electrodes exhibited strong catalytic activity and excellent flexibility, showing no obvious change in their sheet resistances after 10000 cycles of bending. The integrated quasi-solid-state DSSC device with a TiO2 nanotube/Ti mesh photoanode and a ST-PEDOT:PSS/L-rGO counter electrode exhibited an energy conversion efficiency (~/) of about 1.8%. It also displayed an excellent mechanical stability and durability after bending for 1000 cycles at a small curvature radius of 10 mm. The high flexibility, low cost and efficient catalytic activity make ST-PEDOT:PSS/L-rGO composite films promising counter electrodes for flexible DSSCs.展开更多
In this communication, the synthesis and structural, morphological, optical, and photo-electrochemical properties of TiO2 and CaCO3/TiO2 nanoparticles as well as their applications in dye sensitized solar cells (DSSC...In this communication, the synthesis and structural, morphological, optical, and photo-electrochemical properties of TiO2 and CaCO3/TiO2 nanoparticles as well as their applications in dye sensitized solar cells (DSSCs), have been reported. In an X-ray diffraction pattern of CaCO3/TiO2 nanoparticles, the peak at 29.41 ° of CaCO3 has been detected, demonstrating its coating on the surface of TiO2, which is further verified using high resolution-transmission electron microscopy, energy dispersive X-ray spectroscopy and Fourier transform infrared spectroscopy. The strong quenching in photoluminescence emission, in the case of CaCO3/TiO2 nanoparticles, has been attributed to the decrease in recombination rate of photo-generated electron-hole pairs. In the case of UV-visible reflectance spectra, the absorption edge for CaCO3/TiO2 nanoparticles has slightly been found to be blue-shifted as compared to bare TiO2 nanoparticles, which corresponds to an increase in energy band gap of the former. The dye desorption studies reveal that CaCO3/TiO2 electrodes adsorbed more dye than the bare TiO2 electrode. CaCO3/TiO2 based DSSC show improved photo- electrochemical properties compared to the bare TiO2 based DSSC as CaCO3 coating on mi02 forms an energy barrier, and, consequently suppressing the charge recombination, and, thus, improving the overall energy conversion efficiency (η) from 0.46% to 1.44% under the illumination of simulated light of 100 mW/cm2.展开更多
To develop efficient concerted companion(CC)dyes for fabricating high-performance DSSCs,three organic dyes XL1-XL3 have been designed by varying the position and number of theβ-hexylthiophene(HT)bridges,and these org...To develop efficient concerted companion(CC)dyes for fabricating high-performance DSSCs,three organic dyes XL1-XL3 have been designed by varying the position and number of theβ-hexylthiophene(HT)bridges,and these organic dye units are covalently linked with our previously reported porphyrin dye XW10 to construct the corresponding CC dyes XW74-XW76.Among the organic dyes,XL3 contains twoβ-hexylthiophene units at both the donor and acceptor parts and thus possesses stronger light-harvesting capability in the green light region.Because of the most complementary absorption between XL3 and XW10 as well as the excellent photovoltaic behavior of the individual XL3 dye,the corresponding CC dye XW76 affords the best PCE(10.78%)among all the CC dyes.Upon coadsorption with CDCA,XW76 affords a highest PCE of 11.35%,which outperforms the previous cosensitization system of XW10+WS-5.This work provides an approach for developing efficient DSSCs based on CC dyes composed of an organic dye unit with suitableπspacers inserted at appropriate positions.展开更多
A density function theory(DFT) study was made on three dyes based on hydroxamate with different ligands[terpyridine, isothiocyanate(NCS) and 2,2'-bis(thienyl)-tripyrrinate(2-BTTP)] to investigtate their devic...A density function theory(DFT) study was made on three dyes based on hydroxamate with different ligands[terpyridine, isothiocyanate(NCS) and 2,2'-bis(thienyl)-tripyrrinate(2-BTTP)] to investigtate their device performance optimization in dye sensitized solar cell(DSSC). Based on the adsorbed dye on TiO2 (101) surface, the ground state geometry structures, electronic structures, absorption spectra and correspongding charge transfer properties were analysed in detail. The results indicate that the ligand replacement of terpyridine by NCS and 2-BTTP improves the low-energy region absorption of hydroxamate based dyes significantly. The electron injection and light harvesting capability of hydroxamate based dyes are enhanced by NCS and 2-BTTP ligands as well. In the visible region, hydroxamate based dyes have the potentials to become panchromatic light absorbers according to our research.展开更多
文摘A new type of dye-sensitized nanocrystalline solid state photovoltaic cell based on the wide band gap n-TiO2/p-CuI heterojunction was fabricated. Tetra-carboxyphenyl porphyrine (TPP-(COOH)(4)), squarylium cyanine derivative (SQ-(CH2),(SO3Py+)-Py-.) and ruthenium bipyridyl complex (RuL2(NCS)(2)) were used as photosensitizers. Larger photocurrents and photovoltages were shown in the cell sensitized by ruthenium bipyridyl complex and can be further increased by intercalation of a TiO2 thin underlayer.
文摘Titania is one kind of important materials, which has been extensively investigated because of its unique electronic and optical properties. Research efforts have largely focused on the optimization of the dye,but recently the titania nanostructures electrode itself has attracted more attention. It has been shown that particle size, shape, crystallinity, surface morphology, and chemistry of the TiO_2 material are key parameters which should be controlled for optimized performance of the solar cell. Titania can be found in different shape of nanostructures including mesoporous, nanotube, nanowire, and nanorod structures. The present article reviews the structural, synthesis, electronic, and optical properties of TiO_2 nanostructures for dye sensitized solar cells.
文摘Composite nanoporous electrode SnO2/TiO2 was fabricated for the dye sensitized solar cell (DSSC) with N3 (Cis-Ru). After introducing of TiO2, the open-circuit photovoltage (Voc) was higher than that of the pure SnO2 electrode, while short-circuit photocurrent (Isc) was varied with the ratio of the TiO2. Appropriate content of the TiO2 can be beneficial to the efficiency of the solar cell, and it gives negative impact on the composite electrode when the content of TiO2 is higher.
文摘A series of new metal-free organic dyes that contain donors with triphenylamine or its derivatives and tetrazole-based acceptors were synthesized and characterized by photophysical, electrochemical, and the- oretical computational methods. They were applied in nanocrystalline TiO2 solar cells (DSSCs). It is found that the introduction of diphenylamine units as antennas in the as-synthesized dyes could improve photo- voltaic performance compared with phenothiazine and carbazole units as antennas in DSSCs. The dye with (2H-tetrazol-5-yl) acrylonitrile electron acceptor also displayed the highest solar-to-electrical energy conver- sion efficiency.
基金Project 59573009 is supported by the National Natural Science Foundation of China.
文摘The photoinitiating system composed of 1-ethyl-3'-methylthiacyanine bro-mide (C-I), 2-chlorohexaarylbiimidazole (o-Cl-HABI) and 3-mercapto-4-methyl-4H-1, 2, 4-triazole (MTA), which act as sensitizer, initiator and hydrogen-donor respectively, can beused to initiate the polymerization of methyl methacrylate (MMA). The kinetic study wascarried out in trichloromathane solution at 30℃ by using dilatometry. The relation be-tween the polymerization rate and the concentrations of C-I, o-Cl-HABI, MTA and MMAwas studied.
基金financially supported by the National Natural Science Foundation of China (No.21271022)。
文摘Although Bi_(2)Mo O_(6)(BMO) has recently received extensive attention, its visible-light photocatalytic activity remains poor due to its limited photoresponse range and low charge separation efficiency. In this work, a series of visible-light-driven Y^(3+)-doped BMO(Y-BMO) photocatalysts were synthesized via a hydrothermal method. Degradation experiments on Rhodamine B and Congo red organic pollutants revealed that the optimal degradation rates of Y-BMO were 4.3 and 5.3 times those of pure BMO, respectively. The degradation efficiency of Y-BMO did not significantly decrease after four cycle experiments. As a result of Y^(3+)doping, the crystal structure of BMO changed from a thick layer structure to a thin flower-like structure with an increased specific surface area. X-ray photoelectron spectroscopy showed the presence of highintensity peaks for the O 1s orbital at 531.01 and 530.06 eV, confirming the formation of oxygen vacancies in Y-BMO. Photoluminescence(PL) and electrochemical impedance spectroscopy measurements revealed that the PL intensity and interface resistances of composites decreased significantly, indicating reduced electron–hole pair recombination. This work provides an effective way to prepare high-efficiency Bibased photocatalysts by doping rare earth metal ions for improved photocatalytic performance.
基金Project supported by the National Natural Science Foundation of China (81801744)National Key R&D Program of China(2017YFA0205202,2017YFC1309100,2018YFC0910602)。
文摘Lanthanide-doped biocompatible nanoparticles have promising applications in near-infrared second region imaging due to their high chemical stability,enhanced photostability and sharp emission bandwidth.However,the weak light absorption capacity limits the application of rare-earth nanoparticles(RENPs) for bioimaging.We prepared a coumarin-derived dye sensitized NaYGdF4:Yb,Er nanoparticle probe,in which the organic dye enhances photon absorption through the sensitization process,improving the luminescence efficiency of the rare earth particles near 1000 and 1500 nm.In addition,good water solubility and stability of the probe are imparted by coating the particles with amphiphilic polymers distearoyl phosphatidylethanolamine-polyethylene glycol(DSPE-PEG) and polyacrylic acid.This composite probe with good biocompatibility and NIR Ⅱ luminescence properties can be used for vascular imaging,providing a tool for the detection of hematologic-related diseases.
基金This work was financially supported by the National Natural Science Foundation of China(Grant No.51862007)the Western Youth Scholars Program of Chinese Academy of Sciences,and the Young Doctor Fund Project of Gansu Provincial Department of Education(Grant No.2022QB-156).
文摘TiO_(2) nanoparticles(NPs)in the size of-25 nm,namely P25,are very common material as the electron collecting layer in dye-sensitized solar cells(DSsCs).However,the light-scattering improvement of TiO2 NP photoelectrodes is stll a challenge.Here,we built TiO2 cavities on the top of the TiO2 NP layer by using carbonaceous microspheres as the template,forming the TiO_(2) cavity/nanoparticle(C/NP)photoelectrode for the application in DSSCs.The cavity amount in the TiO_(2) C/NP photoelectrode was controlled by adjusting the weight ratio of carbonaceous microspheres.SEM results confirm the successful formation of the double-layered TiO_(2) C/NP electrode.J-V tests show that the optimized TiO_(2) C/NP electrode prepared with 25 wt.%carbonaceous microspheres contributes to remarkable improvement of the short-circuit current density(Jsc)and the power conversion efficiency(PcE).The best photovoltaic performance solar cell with the PCE of 9.08%is achieved with the optimized TiO_(2) C/NP photoelectrode,which is over 98% higher than that of the TiO_(2) NP photoelectrode.Further investigations of UV-vis DRS,IPCE,OCVD,and EIS demonstrate that the competition between light scattering effect and charges recombination in this TiO_(2) C/NP photoelectrode is responsiblefor the PCE enhancement.
基金financially supported by the National Natural Science Foundation of China(Nos.22131005,22201074,22075077 and 21971063)the Fundamental Research Funds for the Central Universities,Program of Shanghai Academic Research Leader(No.20XD1401400)+1 种基金Shanghai Rising-Star Program(No.23QA1402100)Natural Science Foundation of Shanghai(Nos.23ZR1415600,22ZR1416100).
文摘To develop efficient sensitizers for dye-sensitized solar cells(DSSCs),we recently reported doubly concerted companion(DCC)dye XW83 with a wrapped porphyrin sub-dye unit linked to an organic sub-dye unit through a flexible chain,which exhibits panchromatic absorption and excellent anti-aggregation ability.To further improve the absorption,we herein report XW87 and XW88 by inserting an ethynyl group into the organic sub-dye unit of XW83 near the donor and acceptor,respectively.For the corresponding organic dyes Z3 and Z4,the introduced ethynyl group improves their absorption,but induces aggravated charge recombination,leading to lowered power conversion efficiencies(PCEs).Similar to the organic dyes,the introduced ethynyl group improves the absorption of DCC dyes XW87 and XW88 as well.In addition,the ethynyl group near the acceptor of the organic sub-dye unit can be well protected by the long wrapping chains from the porphyrin unit.As a result,XW88 affords the highest JSC(21.84 mA/cm^(2)),V_(OC)(782 mV)and PCE(12.2%)among the DCC dyes.These results provide an effective method for developing efficient DSSC dyes by inserting an ethynyl group at a suitable position of a DCC dye.
基金This work was sponsored by Shanghai Pujiang Program(No.19PJ1405200)the Startup Fund for Youngman Research at SJTU(SFYR at SJTU,No.WF220516003)。
文摘Developing low-energy input route for conversion of methane(CH_(4))to value-added methanol(CH_(3)OH)at room temperature is important in environment and industry.Bonding in electron donor-acceptor hybrid can potentially promote charge transfer and photocatalytic efficiency of CH_(4) conversion.Herein,bonding in electron donor rhodamine B(RhB)-acceptor(TiO_(2))hybrid(RhB/TiO_(2))significantly promotes the selectivity of photocatalytic oxidation of CH4 to CH3OH and utilization of visible light(low-energy photons)at ambient condition.Even under green light irradiation(λ=550 nm),the noble-metal-free RhB/TiO_(2) hybrid synthesized presents enhanced oxidation of CH4 to CH_(3)OH with a generation rate of 143µmol·g^(−1)·h^(−1) and selectivity of 94%.This work demonstrates the possibility and feasibility of noble-metal-free catalysts for activating CH4 under visible light at room temperature.
基金Financial support for this project was provided by the National Natural Science Foundation of China (Nos.51702023,51702022)Natural Science Research of Jiangsu Higher Education Institutions of China (No.17KJB430001)。
文摘Light utilization is one of the key factors for the improvement of photocatalytic perfo rmance.He rein,we design C-TiO_(2) hollow nanoshells with strong Mie resonance for enhanced photocatalytic hydrogen evolution in a dye-sensitized system under visible light irradiation(λ≥420 nm).By tuning the inner diameters of hollow nanoshells,the Mie resonance in hollow nanoshells is adjusted for better excitation of dye molecules,which thus greatly enhances the light utilization in visible light region.This work shows the potential of Mie resonance in nanoshells can be an alternative strategy to increase the light utilization for photocatalysis.
基金supported by National Research Fund for High-Tech Research and Development of China Program(No. 2007AA05Z439)
文摘The pure TiO2 and Fe salts [Fe(C2O4)3,5H2O]-doped TiO2 electrodes were prepared by the hydrothermal method. The pure TiO2 or Fe-doped TiO2 slurry was coated onto the fluorine-doped tin oxide glass substrate by the Doctor Blade method and then sintered at 450 ℃. The Mott-Schottks, plot indicates that the fiat band potential of TiO2 was shifted positively after Fe-doped TiO2. The positive shift of the fiat band potential improves the driving force of injected electrons from the LUMO of the dye to the conduction band of TiO2. This study shows that photovoltaic efficiency increased by 22.9% from 6.07% to 7.46% compared to pure TiO2, and the fill factors increased from 0.53 to 0.63.
基金X.Z.acknowledges the funding support from National Science Foundation of China(NSFC)(No.61975073 and No.61605076)W.D.thanks the financial support from NSFC(No.11872199 and No.11932009).
文摘Solution processible photovoltaics(PV)are poised to play an important role in scalable manufacturing of low-cost solar cells.Electrospray is uniquely suited for fabricating PVs due to its several desirable characteristics of an ideal manufacturing process such as compatibility with roll-to-roll production processes,tunability and uniformity of droplet size,capability of operating at atmospheric pressure,and negligible material waste and nano structures.This review begins with an introduction of the fundamentals and unique properties of electrospray.We put emphasis on the evaporation time and residence time that jointly affect the deposition outcome.Then we review the efforts of electrospray printing polymer solar cells,perovskite solar cells,and dye sensitized solar cells.Collectively,these results demonstrate the advantages of electrospray for solution processed PV.Electrospray has also exhibited the capability of producing uniform films as well as nanostructured and even multiscale films.So far,the electrospray has been found to improve active layer morphology,and create devices with efficiencies comparable with that of spin-coating.Finally,we discuss challenges and research opportunities that enable electrospray to become a mainstream technique for industrial scale production.
基金supported by the National Natural Science Foundation of China (20925621)Shanghai Rising-Star Program (09QH1400700,09QA1401500)+4 种基金Special Projects for Key Laboratories in Shanghai (09DZ2202000,10DZ2211100)Special Projects for Nanotechnology of Shanghai (0952nm02100)Shanghai Pujiang Program (09PJ1403200)Basic Research Program of Shanghai (10JC1403300)Fundamental Research Funds for the Central Universities
文摘For better performance of dye sensitized solar cells (DSSCs), a bilayer structured electrode was constructed by employing a mesoporous anatase TiO2 overlayer above a commercial P25 TiO2 nanoparticles underlayer. The mesoporous anatase TiO2, prepared through a facile surfactant-assisted sol-gel process, possessed large pore size and well inter-connected network structure, both beneficial for dye adsorption and electron transfer. The dye adsorption capability of the mesoporous TiO2 was nearly twice that of the P25 counterpart. In the electrode, the mesoporous TiO2 film enhanced both dye adsorption and lightharvest, to increase photocurrent (Jsc) from 12.32 to 14.78 mA/cm^2. Compared to the single P25 TiO2 film, the synergy of the mesoporous TiO2 and the P25 TiO2 nanoparticle films in the electrode resulted in a 24% improvement in light-to-electricity conversion efficiency (η). This bilayered electrode provides an alternative approach for further developing a photovoltaic device with better cell performance.
基金supported by Open Research Fund Project of National Engineering Research Center of Seafood (No.2012FU125X03)Key Science and Technology Platform of Liaoning Provincial Education Department (No.2011–191)Science and Technology Platform of Dalian (No.2010–354)
文摘TiO2 nanotube(NT) was firstly prepared on titanium foil by an electrochemical anodization method, and then modified via subsequent deposition of a layer of SrAl2O4:Eu2+ phosphor embedded within TiO2 nanoparticles to fabricate photoanodes of dye–sensitized solar cells(DSSCs). The effect of doping down–conversion Sr Al2O4:Eu2+ phosphor in DSSCs was investigated. SrAl2O4:Eu2+ can effectively convert ultraviolet light to visible light within the range of the dye commonly used in DSSC to increase the photocurrent of DSSC, and enhance the open–circuit voltage by a p–type doping effect. When the ratio of Sr Al2O4:Eu2+ in the doping layer is optimized to be 1wt.%, the photoelectric conversion efficiency of the DSSC reaches 3.09%, which is increased by 38.6%, compared to that of the DSSC without Sr Al2O4:Eu2+ doping.
基金Acknowledgement This work was supported by the National Basic Research Program of China (973 Program, No. 2012CB933402) and the Natural Science Foundation of China (Nos. 51433005, 21274074).
文摘Sulfuric acid-treated poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)/less-defective reduced graphene oxide (ST-PEDOT:PSS/L-rGO) composite films were prepared via a solution-processing route and used as the counter electrodes of dye sensitized solar cells (DSSCs). These platinum (Pt)- and transparent conductive oxide (TCO)-free counter electrodes exhibited strong catalytic activity and excellent flexibility, showing no obvious change in their sheet resistances after 10000 cycles of bending. The integrated quasi-solid-state DSSC device with a TiO2 nanotube/Ti mesh photoanode and a ST-PEDOT:PSS/L-rGO counter electrode exhibited an energy conversion efficiency (~/) of about 1.8%. It also displayed an excellent mechanical stability and durability after bending for 1000 cycles at a small curvature radius of 10 mm. The high flexibility, low cost and efficient catalytic activity make ST-PEDOT:PSS/L-rGO composite films promising counter electrodes for flexible DSSCs.
基金the University Grants Commission(UGC)for the research funding vide sanction letter No.F.No.39-533/2010(SR)of January 2011
文摘In this communication, the synthesis and structural, morphological, optical, and photo-electrochemical properties of TiO2 and CaCO3/TiO2 nanoparticles as well as their applications in dye sensitized solar cells (DSSCs), have been reported. In an X-ray diffraction pattern of CaCO3/TiO2 nanoparticles, the peak at 29.41 ° of CaCO3 has been detected, demonstrating its coating on the surface of TiO2, which is further verified using high resolution-transmission electron microscopy, energy dispersive X-ray spectroscopy and Fourier transform infrared spectroscopy. The strong quenching in photoluminescence emission, in the case of CaCO3/TiO2 nanoparticles, has been attributed to the decrease in recombination rate of photo-generated electron-hole pairs. In the case of UV-visible reflectance spectra, the absorption edge for CaCO3/TiO2 nanoparticles has slightly been found to be blue-shifted as compared to bare TiO2 nanoparticles, which corresponds to an increase in energy band gap of the former. The dye desorption studies reveal that CaCO3/TiO2 electrodes adsorbed more dye than the bare TiO2 electrode. CaCO3/TiO2 based DSSC show improved photo- electrochemical properties compared to the bare TiO2 based DSSC as CaCO3 coating on mi02 forms an energy barrier, and, consequently suppressing the charge recombination, and, thus, improving the overall energy conversion efficiency (η) from 0.46% to 1.44% under the illumination of simulated light of 100 mW/cm2.
基金financially supported by the National Natural Science Foundation of China (Nos. 22131005, 21772041, 21971063 and 22075077)the Program of Shanghai Academic Research Leader (No. 20XD1401400)+1 种基金the Natural Science Foundation of Shanghai (No. 20ZR1414100)the Fundamental Research Funds for the Central Universities (No. 222201717003)
文摘To develop efficient concerted companion(CC)dyes for fabricating high-performance DSSCs,three organic dyes XL1-XL3 have been designed by varying the position and number of theβ-hexylthiophene(HT)bridges,and these organic dye units are covalently linked with our previously reported porphyrin dye XW10 to construct the corresponding CC dyes XW74-XW76.Among the organic dyes,XL3 contains twoβ-hexylthiophene units at both the donor and acceptor parts and thus possesses stronger light-harvesting capability in the green light region.Because of the most complementary absorption between XL3 and XW10 as well as the excellent photovoltaic behavior of the individual XL3 dye,the corresponding CC dye XW76 affords the best PCE(10.78%)among all the CC dyes.Upon coadsorption with CDCA,XW76 affords a highest PCE of 11.35%,which outperforms the previous cosensitization system of XW10+WS-5.This work provides an approach for developing efficient DSSCs based on CC dyes composed of an organic dye unit with suitableπspacers inserted at appropriate positions.
基金Supported by the National Natural Science Foundation of China(No.21173096) and the China Postdoctoral Science Foundation(No.2013M541288).
文摘A density function theory(DFT) study was made on three dyes based on hydroxamate with different ligands[terpyridine, isothiocyanate(NCS) and 2,2'-bis(thienyl)-tripyrrinate(2-BTTP)] to investigtate their device performance optimization in dye sensitized solar cell(DSSC). Based on the adsorbed dye on TiO2 (101) surface, the ground state geometry structures, electronic structures, absorption spectra and correspongding charge transfer properties were analysed in detail. The results indicate that the ligand replacement of terpyridine by NCS and 2-BTTP improves the low-energy region absorption of hydroxamate based dyes significantly. The electron injection and light harvesting capability of hydroxamate based dyes are enhanced by NCS and 2-BTTP ligands as well. In the visible region, hydroxamate based dyes have the potentials to become panchromatic light absorbers according to our research.