Addition Of TBP Research Articles

High moisture extrusion induced interaction of Tartary buckwheat protein and starch mitigating the in vitro starch digestion

This study investigated the effects of adding 4–20 % Tartary buckwheat protein (TBP, with a purity of 93.35 %) on the structural, thermal, and digestive properties of Tartary buckwheat starch (TBS) by high moisture (60 %) extrusion. The added TBP embedded and enwrapped the starch matrix, which formed protein–starch complexes. After adding 4 %–20 % TBP, the shear degradation of AP decreased. Conversely, the shear degradation of AM chains increased. The addition of TBP promoted the retrogradation of starch in extrudates, enhancing their short- and long-range ordered structures. Compared with extruded TBS, extrudates contained TBP showed a reduction of gelatinization enthalpy, a high content of resistant starch, and a lower starch digestibility. These findings provided an insight into the protein–starch interactions under high moisture extrusion, which would promote the advancement of starch-based foods with high TBP content.

Synthesis of CdSe and CdSe/ZnS Quantum Dots with Tunable Crystal Structure and Photoluminescent Properties

Mastery over the structure of nanocrystals is a powerful tool for the control of their fluorescence properties and to broaden the range of their applications. In this work, the crystalline structure of CdSe can be tuned by the precursor concentration and the dosage of tributyl phosphine, which is verified by XRD, photoluminescence and UV-vis spectra, TEM observations, and time-correlated single photon counting (TCSPC) technology. Using a TBP-assisted thermal-cycling technique coupled with the single precursor method, core–shell QDs with different shell thicknesses were then prepared. The addition of TBP improves the isotropic growth of the shell, resulting in a high QY value, up to 91.4%, and a single-channel decay characteristic of CdSe/ZnS quantum dots. This work not only provides a facile synthesis route to precisely control the core–shell structures and fluorescence properties of CdSe nanocrystals but also builds a link between ligand chemistry and crystal growth theory.

Influence of different concentrations of 4-tert-butyl-pyridine in a gel polymer electrolyte towards improved performance of Dye-Sensitized Solar Cells (DSSC)

Developing gel polymer electrolyte (GPE) can solve the safety issues faced by liquid electrolyte and allow easy fabrication of dye-sensitized solar cell (DSSC). However, its power conversion efficiency (η) still needs improvement by bettering any other parameters such as open-circuit voltage (VOC), short–circuit current (JSC) and Fill Factor (FF). Herein, 4-tert-butyl-pyridine (TBP) is used as an additive with different concentrations, and its effects on the GPE-TBP are studied. The addition of TBP is beneficial in DSSC employing GPE-TBP as it can adsorb on the surface of the mesoporous TiO2 photoanode, which leads to the shifting of the quasi-fermi level of TiO2 photoanode to a higher potential. This phenomenon enhances open-circuit voltage (VOC) of the DSSC from 615 to 750 mV upon addition of 7 wt% of TBP content to the GPE sample. However, taking into consideration all parameters in DSSC employing GPE-TBP, GPE sample containing 3 wt% of TBP shows the highest photovoltaic conversion efficiency (ɳ) of 8.11% under light illumination of 100 mW cm−2.

Experimental study on improvement of alcoholic liver disease by polysaccharides from Balanophora henryi through targeting miR-122a

The aim of this paper was to investigate the effect of total polysaccharide from Balanophora henryi(TBP) on alcoholic liver disease(ALD) and explore the possible mechanism. C57 BL/6 N mice were randomly divided into 4 groups: pair-feeding group, alcohol-feeding model group, model+TBP group and TBP drug control group. The Gao-binge method was used to prepare the chronic ALD model, and at the same time, 400 mg·kg~(-1) TBP was given for interventional therapy. After feeding for 6 weeks, the serum, liver and colon tissues were collected for detection. As compared with the pair-feeding group, the model group mice showed obvious fatty degeneration and a large number of infiltration of inflammatory cells in the liver, with increased serum ALT and AST levels. After TBP intervention, histopathological changes in liver tissues were significantly improved, with decreased lipid deposition, closer arrangement of hepatocytes, lower expression level of inflammatory factors, and reduced activity of serum ALT and AST, indicating that TBP had a significant improvement effect on ALD. The observation of colonic tissues in mice showed that TBP effectively maintained the integrity of intestinal tissue structure of mice with ALD, enhanced the expression of tight junction protein occludin and reduced miR-122 a expression level. More importantly, TBP significantly reduced serum lipopolysaccharide(LPS) level in model mice. These results indicated that TBP may improve ALD by maintaining and enhancing intestinal barrier function. In vitro experiments showed that TBP significantly inhibited the expression level of miR-122 a in Caco-2 cells exposed to ethanol. Overexpression of miR-122 a in Caco-2 cells induced the inhibition of occludin protein production, and the addition of TBP significantly interfered with the effect. These results suggested that TBP could improve ALD by maintaining the stability of intestinal barrier function and reducing LPS content into the liver, and the mechanism may be partially related to inhibiting miR-122 a expression.

Interactions Between Ionic Liquid (ALiCY) and TBP and their Use in Hydrometallurgy for Extracting Co(II) and Ni(II)

Ionic liquids have emerged in hydrometallurgy as potential extractants for metals. In this work, the interactions of ALiCY (R4N<sup>+</sup>A<sup>-</sup>) synthesized by Aliquat336 and Cyanex272, and a mixture of ALiCY and TBP, were analyzed using extraction data and FT-IR spectroscopy. Co(II) and Ni(II) were extracted from two HCl concentrations (1.0×10<sup>-4</sup> and 6.8 mol·L<sup>-1</sup>) using ALiCY and its mixture with TBP. The extraction results indicated that ALiCY has a dual function, as a cationic extractant at low HCl concentration and an anionic extractant at high HCl concentration depending on the types of metal complexes. The addition of TBP to ALiCY had a negative effect on the extraction of Co(II) from the 6.8 mol·L<sup>-1</sup> HCl, while the effect was negligible from the 1.010<sup>-4</sup> mol·L<sup>-1</sup> HCl. The solvation of R4N<sup>+</sup> by TBP significantly affected the extraction behavior of ALiCY for metal ions. The formation of hydrogen bonding between TBP and Cyanex272 was verified. These findings shed light on the behavior and interaction occurring between bif-ILs and solvating extractants for the extraction of metals in acidic media.

Synthesis of succinimide based ionic liquids and comparison of extraction behavior of Co(II) and Ni(II) with bi-functional ionic liquids synthesized by Aliquat336 and organophosphorus acids

Two new succinimide compounds such as 3-butyl-1-methyl-1H-imidazol-3-ium 4-(dioctylamino)-4-oxobutanoate ([N88SA]−[C4min]+) and 1-butylpyridin-1-ium 4-(dioctylamino)-4-oxobutanoate ([N88SA]−[C4Py]+) were synthesized as task-specific ionic liquids (TSILs) for the extraction of metal ions. The extraction behavior of Co(II) and Ni(II) from chloride solution was compared between these TSILs and Bif-ILs synthesized from Aliquat336 and organophosphorus acids such as Cyanex 272, PC 88A and D2EHPA. The extraction percentage of Co(II) and Ni(II) by TSILs was eight times higher than that by Bif-ILs at the initial pH of 4.0. Moreover, the extraction percentage of Ni(II) by the TSILs was slightly higher than that of Co(II). However, Bif-ILs extracted more hydrogen ions than TSILs. The extraction of Co(II) and Ni(II) by [N88SA]−[C4min]+ was higher than that by [N88SA]−[C4Py]+. The addition of TBP to TSILs reduced the extraction of metals but the loss of TSILs into the aqueous was significantly decreased. Succinimide ionic liquids can be employed for the extraction of metals from weak acidic solutions.

Selective Extraction of Cu(II) from Sulfuric Acid Leaching Solutions of Spent Lithium Ion Batteries Using Cyanex 301

Spent lithium ion batteries contain cobalt, copper, lithium, manganese and nickel. Recovery of these metals with high purity from spent lithium ion batteries is of importance. A sulfuric acid solution is generally employed for the treatment of spent lithium ion batteries, but it is difficult to separate these metal ions from the leaching solution because the divalent metal ions have similar extraction behaviors. Once Cu(II) is separated from the sulfuric acid leaching solution, the traditional solvent extraction process for the separation of Co(II) and Ni(II) can be applied to the raffinate. Therefore, selective extraction of Cu(II) was investigated in this work using Cyanex 301. The effect of the concentration of sulfuric acid and Cyanex 301 was investigated. Within the sulfuric acid concentration range (pH 5-2.0 M) employed in this work, Cu(II) was completely extracted by Cyanex 301, while the extraction percentage of other metal ions decreased to negligible when the sulfuric acid concentration increased to 2.0 M. The addition of TBP to Cyanex 301 depressed the extraction of other metal ions except Cu(II) at an initial pH of 3, facilitating the selective extraction of Cu(II). The McCabe-Thiele extraction diagram indicates that most of the Cu(II) was extracted by two count-current extraction at an A/O ratio of 2. The Cu(II) loaded in Cyanex 301 was completely stripped by using 5% aqua regia. Key words: spent lithium ion batteries, sulfuric acid, Cyanex 301, copper(II), extraction

Electrolyte tuning in dye-sensitized solar cells with N-heterocyclic carbene (NHC) iron(II) sensitizers.

We demonstrate that the performances of dye-sensitized solar cells (DSCs) sensitized with a previously reported N-heterocyclic carbene iron(II) dye in the presence of chenodeoxycholic acid co-adsorbant, can be considerably improved by altering the composition of the electrolyte while retaining an I−/I3− redox shuttle. Critical factors are the solvent, presence of ionic liquid, and the use of the additives 1-methylbenzimidazole (MBI) and 4-tert-butylpyridine (TBP). For the electrolyte solvent, 3-methoxypropionitrile (MPN) is preferable to acetonitrile, leading to a higher short-circuit current density (JSC) with little change in the open-circuit voltage (VOC). For electrolytes containing MPN, an ionic liquid and MBI (0.5 M), DSC performance depended on the ionic liquid with 1-ethyl-3-methylimidazolium hexafluoridophosphate (EMIMPF) > 1,2-dimethyl-3-propylimidazolium iodide (DMPII) > 1-butyl-3-methylimidazolium iodide (BMII) ≈ 1-butyl-3-methylimidazolium hexafluoridophosphate (BMIMPF). Omitting the MBI leads to a significant improvement in JSC when the ionic liquid is DMPII, BMII or BMIMPF, but with EMIMPF the removal of the MBI additive results in a dramatic decrease in VOC (542 to 42 mV). For electrolytes containing MPN and DMPII, the effects of altering the MBI concentration have also been investigated. Although the addition of TBP improves VOC, it causes significant decreases in JSC. The best performing DSCs with the NHC-iron(II) dye employ an I−/I3−-based electrolyte with MPN as solvent, DMPII ionic liquid (0.6 M) with no or 0.01 M MBI; values of JSC = 2.31 to 2.78 mA cm−2, VOC = 292 to 374 mV have been achieved giving η in the range of 0.47 to 0.57% which represents 7.8 to 9.3% relative to an N719 reference DSC set at 100%. Electrochemical impedance spectroscopy has been used to understand the role of the MBI additive in the electrolytes.

Thermodynamical and catalytic aspects of zinc separation from aqueous solution

Abstract The present research work examines extraction mechanism of zinc by D2EHPA (Di-2-ethyl hexyl phosphoric acid) and comprehensively studies the main effective parameters on the process. Results of thermodynamic experiments showed that zinc extraction by D2EHPA was endothermic and spontaneous, and thermodynamic parameters including entropy and enthalpy were + 27.37 J·mol−1·K−1 and 25.21 kJ·mol−1, respectively. Gibbs free energy was varied between − 7.21 kJ·mol−1 and − 8.41 kJ·mol−1 with the variation of temperature from 20 °C to 70 °C. Solution ionic strength was increased by addition of potassium and lithium sulfate solution while addition of calcium sulfate decreased ionic strength whereby zinc extraction efficiency was also decreased. TBP showed positive synergism at concentration of 5% (v/v) and negative synergism effect at concentrations of 2% and 10%. Simultaneous addition of both TBP and salt caused extraction efficiency to drop significantly and lower both TBP and ionic strength efficiency. Results showed that a continuous addition of TBP tends to effectively improve the zinc extraction efficiency. Experiments in the presence of catalyst Ni-Raney demonstrated that zinc extraction kinetic increases remarkably and due to easy recycling of the catalyst, we can propose a novel idea in solvent extraction field.

Dye-sensitized solar cells with electrodeposited ZnO and Co(bpy)3 redox electrolyte: Investigation of mass transport in the electrolyte and interfacial charge recombination

Low-temperature electrodeposited ZnO has been used as a mesoporous photoanode in dye-sensitized solar cells and was investigated by photoelectrochemical techniques when used in combination with the organic sensitizer DN216 and the outer-sphere Co2+/3+(bpy)3 redox couple. The effect of the steric properties of the Co3+ species on its diffusion inside the narrow channels in the porous matrix have been studied by electrochemical impedance spectroscopy and asymmetric mass transport characteristics in the cells were revealed which asked for an extension of existing models. It was found that a downward-shifted conduction band edge of the ZnO as well as a low electron lifetime limit the open-circuit photovoltage and thus the efficiency of the solar cells. The electron lifetime could be recovered by the addition of TBP to the electrolyte which is hindering electron recombination from the ZnO with the oxidized redox species. In this study it was demonstrated that it is possible to achieve high photocurrent densities with the Co(bpy)3 redox couple despite of the attenuated mass transport inside the porous network and steps for further optimization are discussed.

Separation of iridium(IV) and rhodium(III) from hydrochloric acid solution by solvent extraction with Cyanex 921

ABSTRACTThe separation of Ir(IV) and Rh(III) by solvent extraction with Cyanex 921 was investigated in the HCl concentration ranges from .1 to 9 M. Ir(IV) was selectively extracted over Rh(III) by Cyanex 921 in the experimental ranges. Ir(IV) extraction was greatly affected by HCl concentration, while Rh(III) extraction was insensitive to HCl concentration. The highest separation factor between Ir(IV) and Rh(III) was obtained at 1 M HCl solution. The addition of TBP prevented the formation of a third phase and improved phase separation. Both metals ions were completely stripped from the loaded Cyanex 921 by HCl, (NH4)2S2O3, NH4Cl, NaSCN, HClO4, NaOH, and (NH2)2CS, while employment of (NH4)2S2O3 solution led to selective stripping of Ir(IV) over Rh(III). A process for the separation of Ir(IV) and Rh(III) can be developed by extraction with Cyanex 921 followed by stripping with (NH4)2S2O3.

Solvent extraction equilibrium and modeling studies of manganese from sulfate solutions by a mixture of Cyanex 301 and TBP

Studies on solvent extraction equilibrium of Mn(II) from sulfuric acid solutions with a mixture of Cyanex 301 and TBP have been carried out. The extraction of Mn(II) by Cyanex 301 was enhanced significantly by the addition of TBP at a Cyanex 301 mole fraction of 0.6 and the synergistic coefficient calculated was 1.16. Synergistic extraction reaction was identified on the basis of slope analysis and extracted species was proposed to be MnA2·TBP. The solvent extraction equilibrium constant was estimated from the extraction data by considering the formation of complexes and activity coefficients of metal species in the aqueous phase. There was a good agreement between calculated distribution ratios of Mn(II) and experimentally measured values.

Effect of the acceptor on the performance of dye-sensitized solar cells

Three new phenothiazine dyes were designed and synthesized, utilizing different acceptor groups. Upon application to TiO2-based solar cells, the effects of different acceptors on the photophysical and electrochemical properties of the dyes and the solar cell performance are detailed. The introduction of a pyridinium unit or 5-carboxy-1-hexyl-2,3,3-trimethyl-indolium unit into the molecular frame as the acceptor instead of cyano acrylic acid can effectively cause a red shift in the absorption spectra. Applied to DSSCs, the devices sensitized by CM502 with the pyridinium unit as the acceptor show the highest efficiency of 7.3%. The devices fabricated with dye CM501 with cyano acrylic acid as the acceptor exhibited the highest Voc while for the devices sensitized by the dye CM503 with 5-carboxy-1-hexyl-2,3,3-trimethyl-3H-indolium unit as the acceptor, the Voc value was the lowest, at 494 mV. The addition of TBP in the electrolyte can improve the performance of DSSCs fabricated using CM501 and CM502, with the Voc value greatly improved but the Jsc value slightly decreased. However, with the addition of TBP in the electrolyte, the efficiency of the cells sensitized by CM503 dropped significantly (from 4.9% to 1.0% when 0.1 M TBP was added).

Directly Determine an Additive-Induced Shift in Quasi-Fermi Level of TiO2 Films in Dye-Sensitized Solar Cells

The shifts in quasi-Fermi level (QFL) of TiO2 films affected by additives are directly measured using three-electrode dye-sensitized solar cells (DSCs). The difference in QFL of TiO2 under short circuit and open circuit are also analyzed. It is found that the QFL difference between the electrolyte side of the TiO2 film and the equilibrium redox potential, as well as the QFL difference between the two sides of the TiO2 film shift to higher potential owing to the addition of TBP to the electrolyte. The shift values are influenced by the cations present in the electrolyte. These directly determined changes in QFL in TiO2 films both under open circuit and short circuit may provide valuable information for studying DSC operation mechanisms such as the dynamics of charge separation and charge recombination processes.

Extraction of molybdenum from nitric acid solutions with solutions of dibutyl hydrogen phosphate zirconium salt

The extraction of Mo with a solution of dibutyl hydrogen phosphate (HDBP) zirconium salt (ZS) in xylene and in TBP-xylene and TBP-decane mixtures was studied in comparison with the Mo extraction in similar systems without Zr. The Mo extraction is enhanced to the largest extent (by a factor of 7 with 1.5 M HNO3) at the HDBP: Zr ratio of 12, but the majority of experiments were performed at the ratio HDBP: Zr = 9, characteristic of the extraction of TPE and REE. The plots of D Mo vs. HNO3 concentration in all the cases pass through a minimum at ∼3 M HNO3, and the minimum is the deeper, the higher the TBP concentration. At the same time, in the system with HDBP ZS at the TBP concentration in the solvent exceeding 50%, further decrease in D Mo is not observed. The dependence of the Mo distribution ratio D Mo on the HDBP concentration at a fixed ratio HDBP: Zr = 9, the composition of the saturated systems, and the spectra of the saturated and unsaturated (with respect to Mo) systems suggest formation of mixed HDBP-Zr-Mo complexes. Assumptions concerning their composition and structure were made. According to the IR data, in these complexes in the absence of TBP the nitrate ion is not coordinated to the Mo atom. Bridged structures Mo-O-Mo are not formed either. Addition of TBP leads to a decrease in D Mo in the extraction with HDBP ZS, but, at the same time, the slope of the dependence of D Mo on the HDBP concentration increases, and the limiting capacity of the solvent for Mo also somewhat increases. These effects are primarily attributed to an increase in the HNO3 concentration in the organic phase in the presence of TBP.

Effect of dye coverage on photo-induced electron injection efficiency in N719-sensitized nanocrystalline TiO 2 films

The effect of dye coverage on the photo-induced electron injection efficiency in N719-sensitized nanocrystalline TiO 2 films was studied by transient absorption spectroscopy. We evaluated the electron injection efficiency of films with several dye concentrations on the surface and found no significant difference between them. We also studied the suppression of the efficiency by the addition of tBP (4- tert-butylpyridine) and found that the effect of tBP was more pronounced for films with lower dye loading. This suggests that sensitizer dyes adsorbed densely onto the surface suppress the adsorption of tBP.

Effect of counter electrode, thickness and sintering temperature of TiO 2 electrode and TBP addition in electrolyte on photovoltaic performance of dye sensitized solar cell using pyronine G (PYR) dye

Dye sensitized solar cells (DSSCs) assembled with nano-crystalline TiO 2 adsorbed with pyronine G (PYR) dye as photoanode and polar solvent-treated poly(3,4-ethylene dioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) coating on a conductive glass (fluorine-doped thin oxide, FTO), as a counter electrode were studied. It was found that the DSSC using carbon black (0.2 wt%) modified DMSO-PEDOT:PSS conductive coating as a counter electrode resulted highest power conversion efficiency. This is attributed to the role of DMSO in enhancing the conductivity of a PEDOT:PSS film and carbon black plays a vital role in increasing the catalytic activity of the film due to its larger surface area. The solar cell performance was studied as a function of sintering temperature and thickness of TiO 2 layer, dye sensitization time of TiO 2 electrode and electrolyte composition. The DSSCs consist of TiO 2 electrode sintered at a temperature of 450 °C shows higher photocurrent attributed to the formation of higher crystalline film. This enhancement in the interconnection between particles results a swift diffusion of electrolyte and good transportation of electrons in the film. All types of DSSC possess the same dependence of performance on the photoanode thickness, i.e. the efficiency increases with the anode thickness to a maximum value, and then decreases slightly when the thickness of photoanode increases further. The effect of pyridine derivative addition in electrolyte on the performance of photovoltaic parameters of DSSCs has also been investigated. A reduced interface defect density and a resulting reduction of charge carrier recombination were found to be the main mechanism for an increased open circuit voltage of DSSCs with TBP addition in the electrolyte. The negative shift of conduction band edge of TiO 2 after the addition of TBP in electrolyte was also to be a factor in improving the open circuit voltage. The over all power conversion efficiency of the DSSCs with TBP in the electrolyte is about 5.24%.

Interaction between TBP and D2EHPA during Zn, Cd, Mn, Cu, Co and Ni solvent extraction: A thermodynamic and empirical approach

The objective of this study was to investigate the synergistic effect of TBP on the system D2EHPA/kerosense/M 2+ with respect to the extraction of some transitional metals. Although the presence of M2EHPA as an impurity in D2EHPA shifts the extraction curves to lower pH, empirical results show that the extraction curves shift to the right due to the addition of TBP and the counterbalance effect of M2EHPA. The results indicate that the equivalent concentration of D2EHPA decreases as a function of concentration of TBP because of the formation of hydrogen bonds between TBP and D2EHPA. Based on this finding, the D2EHPA equivalent concentration was determined by using a modifying factor for TBP during the extraction of Zn, Cd, Mn, Cu, Co and Ni. To study the effect of TBP on the effective reduction of D2EHPA concentration, the values of this factor were estimated by applying a curve-fitting method.

Solvent extraction of nickel and cobalt with synergistic systems consisting of carboxylic acid and aliphatic hydroxyoxime

Metal extraction pH isotherms and extraction and stripping kinetics have been determined with Versatic 10 acid and LIX® 63 and modifier TBP in an attempt to develop synergistic SX systems for the separation, purification and recovery of nickel and cobalt from leach solutions. The combination of LIX® 63 with Versatic 10 acid resulted in significant synergistic shifts for nickel, cobalt, copper, zinc, and manganese and antagonistic shifts for calcium and magnesium. With the 0.5 M Versatic 10 acid/0.35 M LIX® 63 system, the ΔpH 50 values of nickel, cobalt, copper, zinc and manganese compared to Versatic 10 acid alone were found to be 2.79, 3.50, > 2.0, 1.99 and 1.17 pH units, respectively. The ΔpH 50(Mn–Ni) and ΔpH 50(Mn–Co) values were found to be 1.96 pH and 2.53 pH units, respectively, indicating easy separation of nickel and cobalt from manganese, calcium and magnesium. The extraction and stripping kinetics of cobalt, copper, zinc, and manganese were fast and the extraction and stripping kinetics of nickel were slow with the Versatic 10 acid/LIX® 63 synergistic system. The nickel stripping kinetics increased with the addition of TBP. Within 2 min, the stripping efficiency of nickel increased from 18% with no TBP to 91% with 0.5 M TBP addition. The addition of TBP to the Versatic 10 acid/LIX® 63 system also improved the nickel extraction kinetics. It is proposed that in the Versatic 10 acid/LIX® 63 synergistic system, LIX® 63 plays the role of an extractant and Versatic 10 acid a synergist for nickel while LIX® 63 plays the role of a synergist and Versatic 10 acid an extractant for cobalt.

Role of Electrolytes on Charge Recombination in Dye-Sensitized TiO2 Solar Cell (1): The Case of Solar Cells Using the I-/I3- Redox Couple

Performance of dye-sensitized solar cells (DSCs) was investigated depending on the compositions of the electrolyte, i.e., the electrolyte with a different cation such as Li(+), tetra-n-butylammonium (TBA(+)), or 1,2-dimethyl-3-propylimidazolium (DMPIm(+)) in various concentrations, with and without 4-tert-butylpyridine (tBP), and with various concentrations of the I(-)/I(3)(-) redox couple. Current-voltage characteristics, electron lifetime, and electron diffusion coefficient were measured to clarify the effects of the constituents in the electrolyte on the charge recombination kinetics in the DSCs. Shorter lifetimes were found for the DSCs employing adsorptive cations of Li(+) and DMPIm(+) than for a less-adsorptive cation of TBA(+). On the other hand, the lifetimes were not influenced by the concentrations of the cations in the solutions. Under light irradiation, open-circuit voltages of DSCs decreased in the order of TBA(+)> DMPIm(+) > Li(+), and also decreased with the increase of [Li(+)]. The decreases of open-circuit voltage (V(oc)) were attributed to the positive shift of the TiO(2) conduction band potential (CBP) by the surface adsorption of DMPIm(+) and Li(+). These results suggest that the difference of the free energies between that of the electrons in the TiO(2) and of I(3)(-) has little influence on the electron lifetimes in the DSCs. The shorter lifetime with the adsorptive cations was interpreted with the thickness of the electrical double layer formed by the cations, and the concentration of I(3)(-) in the layer, i.e., TBA(+) formed thicker double layer resulting in lower concentration of I(3)(-) on the surface of the TiO(2). The addition of 4-tert-butylpyridine (tBP) in the presence of Li(+) or TBA(+) showed no significant influence on the lifetime. The increase of V(oc) by the addition of tBP into the electrolyte containing Li(+) and the I(-)/I(3)(-) redox couple was mainly attributed to the shift of the CBP back to the negative potential by reducing the amount of adsorbed Li cations.