Ruthenium Complex Dye Research Articles

The effect of hydrophobicity of ruthenium complex dyes on photocatalytic water electrolysis

The effect of hydrophobicity of ruthenium complex dyes on photocatalytic water electrolysis

Molecular Structure-Based Prediction of Absorption Maxima of Dyes Using ANN Model

The exponentially growing energy requirements and, in turn, extensive depletion of non-restorable sources of energy are a major cause of concern. Restorable energy sources such as solar cells can be used as an alternative. However, their low efficiency is a barrier to their practical use. This provokes the research community to design efficient solar cells. Based on the study of efficacy, design feasibility, and cost of fabrication, DSSC shows supremacy over other photovoltaic solar cells. However, fabricating DSSC in a laboratory and then assessing their characteristics is a costly affair. The researchers applied techniques of computational chemistry such as Time-Dependent Density Functional Theory, and an ab initio method for defining the structure and electronic properties of dyes without synthesizing them. However, the inability of descriptors to provide an intuitive physical depiction of the effect of all parameters is a limitation of the proposed approaches. The proven potential of neural network models in data analysis, pattern recognition, and object detection motivated researchers to extend their applicability for predicting the absorption maxima (λmax) of dye. The objective of this research is to develop an ANN-based QSPR model for correctly predicting the value of λmax for inorganic ruthenium complex dyes used in DSSC. Furthermore, it demonstrates the impact of different activation functions, optimizers, and loss functions on the prediction accuracy of λmax. Moreover, this research showcases the impact of atomic weight, types of bonds between constituents of the dye molecule, and the molecular weight of the dye molecule on the value of λmax. The experimental results proved that the value of λmax varies with changes in constituent atoms and types of bonds in a dye molecule. In addition, the model minimizes the difference in the experimental and calculated values of absorption maxima. The comparison with the existing models proved the dominance of the proposed model.

Toward Eco-Friendly Dye-Sensitized Solar Cells (DSSCs): Natural Dyes and Aqueous Electrolytes

Due to their low cost, facile fabrication, and high-power conversion efficiency (PCE), dye-sensitized solar cells (DSSCs) have attracted much attention. Ruthenium (Ru) complex dyes and organic solvent-based electrolytes are typically used in high-efficiency DSSCs. However, Ru dyes are expensive and require a complex synthesis process. Organic solvents are toxic, environmentally hazardous, and explosive, and can cause leakage problems due to their low surface tension. This review summarizes and discusses previous works to replace them with natural dyes and water-based electrolytes to fabricate low-cost, safe, biocompatible, and environmentally friendly DSSCs. Although the performance of “eco-friendly DSSCs” remains less than 1%, continuous efforts to improve the PCE can accelerate the development of more practical devices, such as designing novel redox couples and photosensitizers, interfacial engineering of photoanodes and electrolytes, and biomimetic approaches inspired by natural systems.

An efficient visible-light-responsive surface charge transfer complex AA-TiO2 based dye-sensitized solar cell

This work investigated a new strategy for visible light responsive dye-sensitized solar cell：the ligand-to-metal charge transfer (LMCT) takes place between TiO2 nanoparticles and ascorbic acid (AA). The surface LMCT complex AA-TiO2 extended the spectral responsive range to 800 nm and exhibited prominent visible light activity, enhancing utilization of the solar spectrum. The optimal photovoltaic conversion efficiency of the visible-light-responsive AA-TiO2 based dye-sensitized solar cell reach value of 3.50 %. The low-cost, non-toxic and environment friendly surface adsorbate AA will demonstrate a feasible approach for replacing the most common used ruthenium complex dyes, thereby offering a strategy for development of low-cost and high efficiency DSSCs.

Construction of bi-layer biluminophore fast-responding pressure sensitive coating for non-contact unsteady aerodynamic testing

Abstract Herein we report on a biluminophore fast-responding pressure sensitive coating with a bi-layer structure prepared by a non-sensitive reference base paint and subsequently a classic polymer-ceramic pressure sensitive paint (PSP). The coating procedure is fully sprayable and allows the separation of the two luminophores in each layer to prevent their interference that may affect the pressure responsibility. The major advance is the use of sol-gel process of tetraethoxysilane (TEOS) and methyltriethoxysilane (MTES) to make the bottom reference layer which ensures the spreading and affinity of the top PSP, composed of a room-temperature vulcanizing silicone rubber (RTV), so that very thin PSP layer, i.e. less than 5 μm, was achieved. Besides, silane-functionalized carbon dots (CDs) was selected as the reference probe, for it could be well-incorporated with the TEOS/MTES matrix, and gained high loading level and hence strong luminescence of the basecoat to overcome the attenuation effect of the top PSP layer. The resultant biluminophore bi-layer fast-responding PSP (denoted as Fast bi-PSP) showed two completed separated emissions with λmax at 430 and 600 nm for the incorporated CDs and the oxygen sensitive ruthenium complex dye, which enables the utility of intensity ratio from blue and red luminescence for the measurement of surface pressure by following Stern-Volmer relationship. Using a shock tube, the response time of the Fast bi-PSP coating was determined to be 0.4–0.6 ms according to the chemical composition. The ability of the coating for monitoring the dynamic evolution of full-field surface pressure was demonstrated on sample plates at attack angles of 0° and 5°. Our work suggests a facile but efficient way for the future design of self-referenced photoluminescent non-contact surface pressure sensing systems.

A Co-Sensitization Process for Dye-Sensitized Solar Cell: Enhanced Light-Harvesting Efficiency and Reduced Charge Recombination

A ruthenium complex dye (N719) and a metal-free phenothiazine-based dye (PTZ-4) were used for the co-sensitized dye-sensitized solar cell (DSSC), intending to achieve complementary absorption spectra and reduce charge recombination, thereby improvement in the performance. Upon co-sensitization, the device made of the N719+PTZ-4 system yielded short-circuit photocurrent density (Jsc) of 16.69mA cm−2, open circuit voltage (Voc) of 0.75V, fill factor (FF) of 0.67 and power conversion efficiency (PCE) of 8.42%; this performance is superior to that of either individual device made from dye N719 (PCE = 7.11%) or dye PTZ-4 (PCE = 5.14%). The improved performance ascribes to effectively enhance light-harvesting efficiency and reduce charge recombination by the co-sensitization process.

Interface engineering of cross-linkable ruthenium complex dye to chelate cations for enhancing the performance of solid-state dye sensitized solar cell

In this study a cross-linkable ruthenium complex dye, Ru(2,2′-bipyridine-4,4′-bicarboxylic acid)(4,4′-bis((4-vinyl-benzyloxy)methyl)-2,2′-bipyridine)(NCS)2 denoted as RuS, was applied to the solid-state dye-sensitized solar cell, by which the photovoltaic performance was superior to the traditional N3 dye. However, the power conversion efficiency (PCE) was only 1.48%, resulting from poor pole filling of the hole conductor, 2,2′,7,7′-tetrakis-(N,N-di-4-methoxyphenylamino)-9,9′-spirobifluorene (spiro-OMeTAD). To modify the interface between RuS and spiro-OMeTAD, additional 4,4′-bis((4-vinylbenzyloxy)methyl)-2,2′- bipyridine (BVP) ligand was employed to crosslink with RuS. The cross-linked dye (denoted as RuS-BVP) on TiO2 was more sustainable and the PCE rose to 2.12%. Besides, the outward bipyridine groups of RuS-BVP are capable of chelating cations. As lithium bis(trifluoromethane)sulfonimide was applied to modify the interface between RuS-BVP and spiro-OMeTAD, the PCE increased to 2.55% and the interfacial resistance for charge transfer under sunlight dramatically decreased. As divalent cation compounds such as magnesium, calcium and barium acetylacetonate were individually adsorbed onto the RuS-BVP, the cell with magnesium acetylacetonate has the highest PCE of 2.82%, highest open circuit voltage and lowest interfacial resistance. The results suggest that the cations with higher charge density have stronger Coulomb's force to couple between RuS-BVP and spiro-OMeTAD.

Ruthenium Dye (N3) Removal from Simulated Wastewater Using Bamboo Charcoal and Activated Bamboo Charcoal

The presence of heavy metals such as mercury (Hg), cadmium (Cd), arsenic (As), chromium (Cr), thallium (T1) and ruthenium (Ru) in wastewater, even in trace quantities, could cause a negative impact on our health. The adsorption method has been proven to be the most effective and low-cost method for removing of heavy metals from wastewater. In this study, biomass waste was used as a low-cost precursor for the production of cost-effective charcoal and activated carbon. Solid waste from a common local bamboo species (Gigantochloa sp.) was used to produce charcoal and activated carbon. The simulated wastewater was made with Ruthenium complex (N3) dye solution as the adsorbate. The bamboo charcoal was prepared by carbonization, and activated carbon was prepared by NaOH activation after carbonization. The morphological characteristics, chemical compositions, and the lattice structures of the prepared adsorbents were analyzed using SEM, EDX, and XRD. The adsorption performance of the prepared adsorbents toward N3 dye was evaluated, and the highest adsorption capacity of 1.50 mg/g was obtained from activated carbon. The results showed that the activated bamboo-based charcoal has a better adsorption efficiency when compared to the bamboo charcoal for the treatment of N3 dye in wastewater.

Effect of composition of chlorophyll and ruthenium dyes mixture (hybrid) on the dye-sensitized solar cell performance

The fabrication of dye-sensitized solar cell (DSSC) has been conducted by varying the composition of natural dye from moss chlorophyll (Bryophyte) and synthesis dye from ruthenium complex N719. The sandwich structure of DSSC consists of the working electrode using TiO2, dye, electrolyte, and counter electrode using carbon. The composition of chlorophyll and synthesis dyes mixture were 100% and 0%, 80% and 20%, 60% and 40%, 40% and 60%, and 20% and 80%. The UV-Vis absorption spectra of moss chlorophyll showed the first peak in the wavelength range of 450-500 nm and the second peak at wavelength of 650-700 nm. The peak value of absorbance at wavelengths of 450-500 nm was 6.1004 and at wavelengths of 650-700 nm was 3.5835. The IPCE characteristic curves showed the absorption peak of photon for DSSCs occurred at wavelength of 550-650 nm. It considered that photon in this wavelength can contribute dominantly to produce the optimum electrons. The I-V characteristics of DSSCs with composition of chlorophyll and synthesis dyes mixture of 100% and 0%, 80% and 20%, 60% and 40%, 40% and 60%, and 20% and 80% resulted the efficiency of 0.0022; 0.0194; 0.0239; 0.0342; and 0.0414, respectively. It suggested that the addition of a little composition of the ruthenium complex dye into moss chlorophyll dye can increase the efficiency significantly.

Single crystal ruthenium(II) complex dye based photodiode

The electrical and photoresponse properties of Ruthenium(II) complex dye based on photodiode were analyzed by current, capacitance and conductance measurements performed in a wide illumination intensity and frequency range. It was observed that the reverse current increases with increasing illumination intensity. The results confirm that the photodiode exhibits a photoconducting behavior. Also, the transient photocurrent, photocapacitance and photoconductance of the photodiode were investigated as a function of time. It was observed that the values of these parameters increase after illuminating and reach back to original value after turning off the illumination. In addition, the interface states and series resistance of the photodiode were determined from capacitance/conductance–voltage measurements. The value of these parameters decreases with increasing frequency. The obtained experimental results suggest that the photodiode with Ruthenium/Ru(II) complex thin film could be used in various optoelectronic devices and applications.

Visible‐Light‐Driven, Tunable, Photoelectrochemical Performance of a Series of Metal‐Chelate, Dye‐Organized, Crystalline, CdS Nanoclusters

CdS nanoclusters of four different sizes were integrated with ruthenium-complex dyes. The cluster-dye crystalline composites, [Cd(4)(SPh)(10)][Ru(bpy)(3)], [Cd(8)S(SPh)(16)][Ru(bpy)(3)], [Cd(8)S(SPh)(13) ⋅Cl⋅(CH(3)OCS(2))(2)][Ru(phen)(3)], [Cd(17)S(4)(SPh)(28)][Ru(bpy)(3)], and [Cd(32)S(14)(SPh)(40)][Ru(phen)(3)](2) (phen=1,10-phenanthroline and bpy=bipyridine), show intense absorption in the visible-light region. They also exhibit size-dependent photocurrent responses under the illumination of visible light. The photocurrent increases with increased cluster size. The dyes also have significant influence on the photocurrent generation of the composite.

Zn2SnO4-Based Dye-Sensitized Solar Cells: Insight into Dye-Selectivity and Photoelectric Behaviors

Infrared dyes in dye-sensitized solar cells (DSCs) usually mismatch with the band structure of TiO2. This mismatch subsequently results in insufficient kinetics in charge separation. Researchers have started focusing on ternary oxide semiconductors because of their stability. Moreover, the chemical compositions and band structures of these semiconductors are easy to control. In this paper, a ternary semiconductor oxide, Zn2SnO4, was synthesized through a hydrothermal method and used as a photoanode for DSCs. Zn2SnO4 selectivity toward organic and ruthenium complex dyes was different from that of TiO2. Zn2SnO4–DSCs performance was improved at a greater degree with organic sensitizer 2-cyano-3-{4-[2-(4- diphenylamino-phenyl)-vinyl]-phenyl}-acrylic acid (TPC) than with cis-bis (isothiocyanato)-bis (2,2-bipyridyl- 4,4-dicarboxylato) ruthenium (II) bis-tetrabutyl-ammonium (N719). We further improved the power conversion efficiency of Zn2SnO4-DSCs to 5.72% through surface modification and structural optimization. Stepped light-induced measurement of photocurrent and photovoltage was used to systematically study electron behaviors in surface-modified and unmodified Zn2SnO4-based and TiO2-based DSCs. Zn2SnO4 exhibited higher electron diffusion coefficient than TiO2. The electron lifetime of Zn2SnO4-based DSCs increased after surface modification.

Photocurrent responsive properties of a series of charge-transfer materials with nano-sized CdS/Se clusters and ruthenium complex dyes

Large cadmium chalcogenido clusters C2 (Cd32) and C1 (Cd17) CdQ (Q = S, Se) with photoactive dye cations [Ru(Phen/Bpy)3]2+ are prepared under solvothermal conditions (Phen = 1,10-phenanthroline, Bpy = 2,2′-bipyridine). All the C2 compounds are 3-D polymeric structures, while the C1 compounds are discrete Cd17 clusters. Two of the 3-D C2 clusters can be considered as homosized nano CdSe@CdS core–shell particles (2.0 nm radius) with Cd4Se10 core. Charge-transfer interaction is found between [Ru(Phen/Bpy)3]2+ cations and CdQ cluster anions. The photocurrent behaviors indicate that (1) the current intensities are greatly increased for the dye cation functionalized Cn clusters, (2) the current intensities of the 3-D C2 clusters are larger than those of the discrete C1 clusters, and (3) the current intensities of the selenide clusters are larger than those of the sulfide clusters.

Design of a Free-Ruthenium In2S3Crystalline Photosensitized Solar Cell

A new type of sulfide-based, solid-state dye material that is sensitive to visible radiation was assessed as a potential replacement for commercial ruthenium complex dyes in a dye-sensitized solar cell (DSSC) assembly. The In2S3crystals on the surface of the TiO2bottom blocking layer were grown as a solid-state dye material. Scanning electron microscopy of In2S3revealed a microsized, 3D-connected sheet-like shape, which was confirmed by X-ray diffraction to be a beta-structure. The efficiency of the dye-sensitized solar cells assembled with a layer grown with In2S3increased with increasing In2S3mole concentrations to 0.05 M (1.02%) but decreased at concentrations greater than 0.6~0.8%. This suggests that crystalline In2S3acts as a dye sensitized to visible radiation, but the short-circuit current density is too low compared to the commercially available ruthenium dye. This suggests that In2S3crystals did not grow densely but were bulk-grown with large pores, resulting in a smaller amount of In2S3per unit area. Two IPCE curves were observed, which were assigned to TiO2and In2S3, meaning that the TiO2surfaces were covered completely with In2S3crystals. The exposure of TiO2eventually leads to a reaction with the electrolytes, resulting in lower quantum efficiency.

Cosensitization of Cyclometalated Ruthenium Complex and Organic Dyes for High-efficiency Dye-sensitized Solar Cells

Abstract Cosensitization of nanocrystalline TiO2 film with the cyclometalated ruthenium complex (FT89) and organic dyes (MK-45 and MK-111) improves the light-harvesting efficiency of dye-sensitized solar cells. The anchor group of the organic dyes has a large influence on the effective cosensitization. MK-45 and MK-111 can work not only as a sensitizer but also as a coadosorbent for FT89. The significant improvement in the conversion efficiency was obtained by cosensitization with FT89 and MK-111, and an efficiency of 11.1% was attained under 100 mW cm−2 of AM1.5G filtered light.

Photovoltaic performance of ruthenium complex dye associated with number and position of carboxyl groups on bipyridine ligands

A series of ruthenium complex dyes with different number and position of carboxyl groups on bipyridine ligands, such as Ru(4-carboxyl-4′-methyl-2,2′-bipyridine)(4,4′-dimethyl-2,2′- bipyridine)(NCS)2 (denoted as Ru1A), Ru(4-carboxyl-4′-methyl-2,2′-bipyridine)2(NCS)2 (Ru11A), Ru(4,4′-dicarboxyl-2,2′-bipyridine)(4,4′-dimethyl-2,2′-bipyridine)(NCS)2 (Ru2A), and Ru(4-carboxyl-4′-methyl-2,2′-bipyridine)(4,4′-dicarboxyl-2,2′-bipyridine)(NCS)2 (Ru3A) were synthesized and compared with Ru(4,4′-dicarboxyl-2,2′-bipyridine)2 (NCS)2, commonly known as N3 dye for the adsorption behavior on the TiO2 surface and photovoltaic properties of dye-sensitized solar cells. The experimental results show that the tilt angle of ruthenium dyes on the TiO2 surface which is dependent on the number and position of their carboxyl groups strongly affected the photovoltaic performance.

Ruthenium complex dye with designed ligand capable of chelating triiodide anion for dye-sensitized solar cells

Ru(4,4′-dicarboxyl-2,2′-bipyridine)[4,4′-bis(styrylaminocarbonyl)-2,2′-bipyridine](NCS)2, denoted as RuAS dye, was synthesized and well characterized by 1H-NMR, 13C-NMR, heteronuclear single quantum coherence, UV-vis and ESI-MS spectra. Its capability of chelating triiodide anions with the 4,4′-bis(styrylaminocarbonyl)-2,2′-bipyridine ligand, which was revealed by ATR-FTIR and 1H-NMR spectroscopies, reduced the charge recombination for dye-sensitized solar cells (DSSCs) by keeping the triiodide ions away from contact with the mesoporous TiO2 layer. Therefore, the open-circuit photovoltage of the DSSC barely changed with the triiodide concentration in the electrolyte. Moreover, the electron-withdrawing ability of the amide groups in the ligand increased the molar extinction coefficient of the dye, leading to the increase of photocurrent for DSSCs. The enhanced photovoltaic performance was further examined by incident photon-to-current conversion efficiency spectra, electrochemical impedance spectroscopy and open-circuit potential decay transient measurements.

Effects of tethering alkyl chains for amphiphilic ruthenium complex dyes on their adsorption to titanium oxide and photovoltaic properties

Ruthenium (II) complex dye, Ru(4,4′-dicarboxyl-2,2′-bipyridine)(4-nonyl-2,2′-bipyridine) (NCS)2, (denoted as RuC9) tethering single alkyl chain was synthesized and well characterized. Its adsorption behavior onto the mesoporous TiO2 and photovoltaic properties were compared with Z907 which has similar chemical structure but tethers two alkyl chains. RuC9 dyes tend to aggregate into vesicles in the acetonitrile/t-butanol co-solvent as a result of the amphiphilic structure, whereas Z907 dyes aggregate into lamellae. The dye-sensitized solar cell (DSSC) with RuC9 dye showed higher short-circuit photocurrent than that with Z907, attributing to its higher molar optical extinction coefficient and more adsorption amount onto the mesoporous TiO2. However, the DSSC with Z907 dye has higher open-circuit photovoltage and power conversion efficiency, presumably due to the fact that Z907 with more alkyl chains formed a molecular layer with higher hydrophobicity. It reduced the charge recombination in the interface between the dye-sensitized mesoporous TiO2 and electrolyte as verified by the electrochemical impedance spectroscopy and intensity modulated photocurrent and photovoltage spectroscopies.

Impedance spectroscopy on dye-sensitized solar cells with a poly(ethylenedioxythiophene):poly(styrenesulfonate) counter electrolyte

We have successfully fabricated the dye-sensitized solar cell (DSSC) devices using ruthenium complex dye, polymer electrolytes, and poly(ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT: PSS) as a counter electrode. The overall power conversion efficiencies of the devices using polyethylene oxide (PEO), polyethylene glycol (PEG), polymethylmethacrylate (PMMA), and polyvinyl acetate (PVAc) as polymer electrolytes were 4.08%, 3.87%, 0.49%, and 0.20%, respectively, while the efficiencies of DSSC devices using Pt counter electrodes showed similar values of 5.7 ± 0.1%. The differences in the efficiencies and the charge transfer resistances (RCT) of the DSSCs with various polymer electrolytes and counter electrodes were measured by using an electrochemical impedance analyzer (EIS) and are discussed.

A Cheap Synthetic Route to Commercial Ruthenium N3 Dye for Sensitizing Solar Cell Applications

Dye-sensitized Solar Cells (DSCs) Have Received Widespread Attention Owing to their Low Cost, Easy Fabrication, and Relatively High Solar-to-electricity Conversion Efficiency. Based on the Tio2 Electrode, Ruthenium Complex Dye, Liquid Electrolyte, and Pt Counter Electrode, Dscs Have Already Exhibited an Efficiency above 11% and Offer an Appealing Alternative to Conventional Solar Cells. however, until now the Commercial and Well Known Standard Dye Is the Ruthenium Complex, Namely, Cis-bis(isothiocyanato)-bis(2,2'-bipyridyl-4,4'dicarboxylato)ruthenium(II) (N3) which Has Been Widely Used around the Word. in this Article, N3 Standard Dye Was Synthesized and Characterized by Two Synthetic Routes: Grätzel’s Protocol and a One-pot Reaction from Cheap and Easily Prepared Starting Materials.