Pt-free Dye-sensitized Solar Cells Research Articles

Spinel cobalt-based binary metal oxides as emerging materials for energy harvesting devices: synthesis, characterization and synchrotron radiation-enabled investigation.

The synthesis and characterization of spinel cobalt-based metal oxides (MCo2O4) with varying 3d-transition metal ions (Ni, Fe, Cu, and Zn) were explored using a hydrothermal process (140 °C for two hours) to be used as alternative counter electrodes for Pt-free dye-sensitized solar cells (DSSCs). Scanning electron microscopy (SEM) and atomic force microscopy (AFM) revealed distinct morphologies for each metal oxide, such as NiCo2O4 nanosheets, Cu Co2O4 nanoleaves, Fe Co2O4 diamond-like, and Zn Co2O4 hexagonal-like structures. The X-ray diffraction analysis confirmed the cubic spinel structure for the prepared MCo2O4 films. The functional groups of MCo2O4 materials were recognized in metal oxides throughout Fourier transform infrared (FTIR) analysis. The local structure analysis using X-ray absorption fine structure (XAFS) at Fe and Co K-edge identified octahedral (Oh) Co3+ and tetrahedral (Td) Co2+ coordination, with Zn2+ and Cu2+ favoring Td sites, while Ni3+ and Fe3+ preferred Oh active sites. Further investigations utilizing the Fourier transformation (FT) analysis showed comparable coordination numbers and interatomic distances ranked as Co-Cu > Co-Fe > Zn-Co > Co-Ni. Furthermore, the utilization of MCo2O4 thin films as counter electrodes in DSSC fabrication showed promising results. Notably, solar cells based on CuCo2O4 and ZnCo2O4 counter electrodes showed 1.9% and 1.13% power conversion efficiency, respectively. These findings indicate the potential of employing these binary metal oxides for efficient and cost-effective photovoltaic device production.

CoS2/RGO hybrid composites as catalysts for efficient counter electrodes in Pt-free dye-sensitized solar cell applications

CoS2/RGO hybrid composites as catalysts for efficient counter electrodes in Pt-free dye-sensitized solar cell applications

Size-Controlled Cu3VSe4 Nanocrystals as Cathode Material in Platinum-Free Dye-Sensitized Solar Cells.

In this work, we report the first single-step, size-controlled synthesis of Cu3VSe4 cuboidal nanocrystals, with the longest dimension ranging from 9 to 36 nm, and their use in replacing the platinum counter electrode in dye-sensitized solar cells. Cu3VSe4, a ternary semiconductor from the class of sulvanites, is theoretically predicted to have good hole mobility, making it a promising candidate for charge transport in solar photovoltaic devices. The identity and crystalline purity of the Cu3VSe4 nanocrystals were validated by X-ray powder diffraction (XRD) and Raman spectroscopy. The particle size was determined from the XRD data using the Williamson-Hall equation and was found in agreement with the transmission electron microscopy imaging. Based on the electrochemical activity of the Cu3VSe4 nanocrystals, studied by cyclic voltammetry, the nanomaterials were further employed for fabricating counter electrodes (CEs) in Pt-free dye-sensitized solar cells. The counter electrodes were prepared from Cu3VSe4 nanocrystals as thin films, and the charge transfer kinetics were studied by electrochemical impedance spectroscopy. The work demonstrates that Cu3VSe4 counter electrodes successfully replace platinum in DSSCs. CEs fabricated with the Cu3VSe4 nanocrystals having an average particle size of 31.6 nm outperformed Pt, leading to DSSCs with the highest power conversion efficiency (5.93%) when compared with those fabricated with the Pt CE (5.85%).

Design and fabrication of NiSe2/g-C3N4 hybrid composite counter electrode for Pt-free dye-sensitized solar cells

Design and fabrication of NiSe2/g-C3N4 hybrid composite counter electrode for Pt-free dye-sensitized solar cells

Fabrication of graphitic carbon nitride-decorated MoSe2 hybrid nanocomposite as an efficient counter electrode for Pt-free dye-sensitized solar cells

Fabrication of graphitic carbon nitride-decorated MoSe2 hybrid nanocomposite as an efficient counter electrode for Pt-free dye-sensitized solar cells

P-doped NiS2/Ni nanoheteroparticles embedded into N-doped carbon framework anchored on multi-walled carbon nanotubes as an efficient counter electrode for Pt-free dye-sensitized solar cells

Designing of inexpensive counter electrode (CE) material with robust electrochemical properties and perfect electrical conductivity is of great essential to improve the power conversion efficiency (PCE) of dye-sensitized solar cells (DSSCs). Herein, the catalytic nickel nanoparticles are in-situ embedded into nitrogen-doped carbon framework (Ni-NC) by high-temperature carbonization. Next, the formed Ni-NC hybrid is subjected to simultaneous sulfurization/phosphorization treatment in the N2 atmosphere to acquire P–NiS2/Ni-NC. Finally, the acquired P–NiS2/Ni-NC hybrid is anchored on functional carboxylated multi-walled carbon nanotubes (MWCNTs) by ultrasonication to obtain P–NiS2/Ni-NC@MWCNTs. According to the electrochemical results, the P–NiS₂/Ni-NC@MWCNTs CE displays remarkable catalytic activities, great electron transfer ability, and high stability in the iodine/iodide electrolyte. DSSC assembled with P–NiS2/Ni-NC@MWCNTs CE yields an impressive PCE of 9.57 %, surpassing those of platinum (Pt) electrode (PCE = 7.84 %) and other corresponding counterparts. Such notable photovoltaic performance can be ascribed to the structural advantages and synergistic coupling effect of NiS2/Ni nanoheterostructure, P doping effect, and the support role of porous carbon network, which offer abundant catalytic active sites, high porosity, and exceptional electrical conductivity. Our work suggests a novel strategy to fabricate Pt-like CE materials based on transition metal sulfides/carbon-based nanostructures with excellent performances for large-scale energy conversion devices to reach the consumer market.

Towards low cost and green photovoltaic devices: Using natural photosensitizers and MoS2/Graphene oxide composite counter electrodes

Photovoltaic systems, for example, dye-sensitized solar cells (DSSCs), are one of the useful tools for producing renewable and green energy. To develop DSSCs technology, it is necessary to overcome obstacles such as the need for expensive compounds. A series of DSSCs were designed and manufactured based on natural dyes extracted from cornelian cherry, black pomegranate, ruby grape, and tangerine peel as photosensitizers. The performance, structure, and interaction of the prepared extracts were evaluated by ultraviolet–visible spectroscopy, cyclic voltammetry, and Fourier transform infrared spectroscopy. Then, the prepared low-cost green dyes were employed in the preparation of DSSCs. A new MoS2/GO hybrid or composite was also employed instead of platinum. The synthesized MoS2/GO hybrid or composite was evaluated by field emission scanning electron microscopy and the results illustrated that the desired compound was synthesized successfully. Finally, DSSCs were prepared using MoS2/GO hybrid or composite and compared with that containing platinum. Under same conditions, the DSSCs with MoS2/GO composite illustrated better efficiency than MoS2/GO hybrid. The co-sensitization of Pt-free DSSC based on natural dyes has been studied for the first time in this work, which provides with expanding photovoltaic absorption range.

A quaternary nanocomposite as an efficient counter electrode for Pt-free Dye-sensitized solar cells (DSSC)

Solar Cells are one of the most promising energy conversion sources available. But most solar cells use conventional Pt as a counter electrode (CE) which is very costly, scarce and corrosive in liquid medium. So, an alternative novel quaternary nanocomposite of rGO Reduced graphene oxide (rGO)/ Manganese dioxide (MnO2)/ Nickel oxide (NiO)/Copper oxide (CuO) (RMNCu) was employed under varied photoanodes like hydrothermally synthesized Titanium dioxide (TiO2), Zinc oxide (ZnO) and TiO2/ZnO with N-719 as dye matrix over Fluorine-doped Tin Oxide (FTO) substrate. The fabricated Dye-Sensitised Solar Cell (DSSCs) were examined under functional, optical and photovoltaic studies. It was found that the prepared DSSC with RMNCu as CE had a Power Conversion Efficiencies (PCE) of 93.31% of Pt-CE in the same ambience. The uplifted conversion efficiency promotes RMNCu as a promising candidate for counter electrodes for DSSC.

Study of Single Diode Model of DSSC Based on Reduced Graphene Oxide as Counter Electrode

We studied the characteristic of reduced graphene oxide (RGO) as a counter electrode (CE) in Pt-free dye-sensitized solar cell (DSSC) using single diode model equation based on current density-voltage (J-V) measurement. The electrical characteristics of DSSC was investigated by electrochemical impedance spectroscopy (EIS) in order to knowing the catalytic properties of RGO as counter electrode. The RGO thin film as CE was deposited on fluorine-doped tin oxide (FTO) substrate and stacked with FTO/TiO2/ruthenium dye/mosalyte/RGO/FTO DSSC structure. The RGO film was obtained from GO (graphene oxide) film that was thermally reduced at 200°C for one hour under argon flow. The performance of DSSC with RGO as CE was characterized by current-voltage measurement and the interface between each layer was observed by Electrochemical Impedance Spectroscopy (EIS). The device efficiency (η) of DSSC that used GO and RGO film as CE are 0.09% and 3.43%, respectively. DSSC parameters such as series resistance (RS) shunt resistance (RSH), and ideality factor (n) were obtained from J-V curve which analyzed using single diode model equation. All samples have a Rs value of 2 indicates that all devices have a good ohmic contact. The RSH of device using RGO-1mg/ml is increase (from 2850 to 3670 Ω.cm2) compared with GO indicate that thermal reduction is successes. The RGO film shows a comparable performance to Pt-conventional CE thus it is a good candidate as alternative of DSSC counter electrode.

Co9S8/NC@FeCoS2/NC composites with hollow yolk shell structure as the counter electrode for Pt-free dye-sensitized solar cells

Carbon-based materials derived from metal-organic framework compounds have tunable chemical composition, morphology, and electrochemically active surface combined with good electrical conductivity and stability. In this work, Fe(OH)3 grows on a zeolitic imidazolate framework, 2-Methylimidazole cobalt salt (ZIF-67), through oxidation and deposition. The Co9S8/NC@FeCoS2/NC composites with hollow yolk shell structure (HYS-Co9S8/NC@FeCoS2/NC) is prepared through solvothermal sulfidation combined with high-temperature carbonization using ZIF-67@Fe(OH)3 as the precursor. A dye-sensitized solar cell assembled with HYS-Co9S8/NC@FeCoS2/NC as a counter electrode achieves a photovoltaic conversion efficiency of 7.07% (PCEPt = 7.36%). The reason for this phenomenon is that the hollow yolk shell structure of Co9S8/NC@FeCoS2/NC material has a high specific surface area, which affords a good deal of active sites and promotes the contact between electrolyte and catalytic sites. The Fe-Co bimetal center synergies with each other to catalyze the reduction of iodide ion, showing a high catalytic activity. Besides, the material has good electrochemical stability in iodide-based electrolysis.

MXene based 2D-2D heterostructures for Counter Electrode in third generation Dye Sensitized Solar Cells

A key issue in realizing the cost-effective large-scale industrial production of third generation dye sensitized solar cells (DSSCs) is the development of competent substitutes for platinum (Pt) counter electrode (CE) having excellent electrocatalytic activity, stability, and ready availability. In the present work, 2D-2D heterostructures of MXene with reduced graphene oxide (M−rGO) and MoS2 (M−MoS2) were synthesized and characterized. M−MoS2 heterostructures turned out to be an effective replacement of Pt CE for the fabrication of efficient Pt-free DSSCs. Further, EIS and CV characterizations were carried out to explain the electrocatalytic and charge transport properties.

Hydrothermal production of low-cost CeNi2S4-reduced graphene oxide composites as an efficient counter electrode for high performance dye-sensitized solar cells

Dye sensitized solar cell (DSSC) technology could become a low-cost solution for solar energy harvesting if the use of expensive dyes and Pt can be avoided. This work reports the development of a novel nanohybrid based on CeNi2S4 nanotubes embedded on sheets of reduced graphene oxide (RGO), which can serve as excellent counter electrode for DSSC showing great promise to replace Pt. The structural and morphological characterization of the nanocomposite synthesized using a simple one step hydrothermal method revealed well defined crystalline nanotubes of CeNi2S4 (with length 190 nm and diameter 8.54 nm) uniformly embedded on the surfaces of the RGO sheets (∼2.65 μm in size). The morphology and size of the nanotubes were found to be dependent on the duration of the hydrothermal reaction. The optimized CeNi2S4/RGO nanohybrid CE when used as counter electrode in DSSC, photo conversion efficiency as high as 9.21 ± 0.03 % was recorded, a value almost equal to that obtained from the DSSC fabricated with Pt as counter electrode and much higher than that with bare CeNi2S4 justifying its potential use in Pt-free DSSC. The improved performance of the electrode have been attributed to the hierarchical nanohybrid structure consisting of catalytically active 1D CeNi2S4 nanotubes embedded on electrically conducting 2D RGO sheets that provides fast ion diffusion pathways, large accessible surface area and good chemical and thermal stability.

MWCNT Aided Cobalt Antimony Sulfide Electrocatalyst for Dye-Sensitized Solar Cells and Supercapacitors: Designing Integrated Photo-Powered Energy System

The objective of this study is to demonstrate low-cost Pt-free Dye-Sensitized Solar Cells (DSSCs) and an electrode for supercapacitor. Cobalt Antimony Sulfide (CoSbS) and Multiwalled Carbon Nanotubes supported CoSbS (CoSbS/MWCNT) composites are synthesized by a simple hydrothermal technique and are used as an electrocatalyst for the reduction of tri-iodide to iodide (). The crystalline structure, morphology, and quantum states of the synthesized samples are analyzed. In a series of electrochemical studies, the CoSbS/MWCNT demonstrated superior electroconductivity and electrocatalytic activity over pristine CoSbS. Notably, the Power Conversion Efficiency (PCE) is reached 6.0% with the CoSbS/MWCNT counter electrode, outpacing the corresponding CoSbS (4.4%) and Co9S8 (1.8%). It is also an effective material for supercapacitors. Moreover, CoSbS/MWCNT has the maximum specific capacity of 382 C g−1 with 3 A g−1 with the acceptable capacitance retention of around 82% over 1000 charge-discharge cycles and excellent rate capability (∼143 C g−1 at 3 A g−1). Through these findings, it can be discovered that CoSbS/MWCNT is not only a feasible substitute for the standard Pt counter electrode in DSSCs but also has the capacity to store energy. The excellent conversion and storage performance highlight the potential of CoSbS/MWCNT for a photo-powered energy system.

Bi 2 S 3 can do it all: Sensitizer, counter electrode, and supercapacitor for symmetric solar cell assisted photo‐supercapacitor

The current research motivation is to fabricate and demonstrate Pt-free dye-sensitized solar cells (DSSCs) at a low-cost and an electrode for supercapacitor. In this study, a well-known sensitizer in quantum dot solar cells, that is, Bi2S3 and Bi2S3/MWCNT hybrids have been synthesized and positioned as an electrocatalyst for the reduction of triiodide to iodide ( I 3 − / I − $$ {I}_3^{-}/{I}^{-} $$ ). Developed DSSC cell-based on Bi2S3/MWCNT counter electrode (CE) achieves a power conversion efficiency of 4.8%, surpassing the corresponding Bi2S3 CE (1.06%) where the efficiency of the present CE yields ~83% of the conventional Pt CE efficiency (~5.8%). In addition, a series of electrochemical investigations reveal that the Bi2S3/MWCNT outperformed the pristine Bi2S3 in terms of electroconductivity and electrocatalytic behavior. This mixture is also favorable for supercapacitors and Bi2S3/MWCNT has the maximum specific capacity of 133 F g−1 with 1 A g−1 in 0.5 M of Na2SO4 with the acceptable capacitance retention of around 80% for 3000 cycles and excellent rate capability (48 F g−1 at 5 A g−1). Besides, the symmetric cell, that is, TiO2/Bi2S3/( I 3 − / I − $$ {I}_3^{-}/{I}^{-} $$ )/Bi2S3 has been manufactured and tested successfully. Thus, Bi2S3 is not only a substitute for the conventional Pt-based CE in DSSCs but also can be a potential energy storage material and sensitizer for photo-supercapacitor applications.

Enhanced Performance of Carbon-Selenide Composite with La0.9Ce0.1NiO3 Perovskite Oxide for Outstanding Counter Electrodes in Platinum-Free Dye-Sensitized Solar Cells.

For large-scale applications, dye-sensitized solar cells (DSSCs) require the replacement of the scarce platinum (Pt)-based counter electrode (CE) with efficient and cheap alternatives. In this respect, low-cost perovskite oxides (ABO3) have been introduced as promising additives to composite-based CEs in Pt-free DSSCs. Herein, we synthesized composites from La0.9Ce0.1NiO3 (L) perovskite oxide and functionalized-multiwall-carbon-nanotubes wrapped in selenides derived from metal-organic-frameworks (f-MWCNT-ZnSe-CoSe2, “F”). L and F were then mixed with carbon black (CB) in different mass ratios to prepare L@CB, F@CB, and L@F@CB composites. The electrochemical analysis revealed that the L@F@CB composite with a mass ratio of 1.5:3:1.5 exhibits better electrocatalytic activity than Pt. In addition, the related DSSC reached a better PCE of 7.49% compared to its Pt-based counterpart (7.09%). This improved performance is the result of the increase in the oxygen vacancy by L due to the replacement of La with Ce in its structure, leading to more active sites in the L@F@CB composites. Moreover, the F@CB composite favors the contribution to the high electrical conductivity of the hybrid carbon nanotube–carbon black, which also offers good stability to the L@F@CB CE by not showing any obvious change in morphology and peak-to-peak separation even after 100 cyclic voltammetry cycles. Consequently, the corresponding L@F@CB-based device achieved enhanced stability. Our work demonstrates that L@F@CB composites with a low cost are excellent alternatives to Pt CE in DSSCs.

Strategic Design of Bifunctional Nis2/Ni9s8 Heterostructured Nanoparticles for Efficient Pt-Free Dye-Sensitized Solar Cells and Hydrogen Evolution Reaction

Strategic Design of Bifunctional Nis2/Ni9s8 Heterostructured Nanoparticles for Efficient Pt-Free Dye-Sensitized Solar Cells and Hydrogen Evolution Reaction

CoSe2/graphene composite: a low-cost, high performance counter electrode for dye sensitized solar cells

In this study, Pt-free dye-sensitized solar cells (DSSCs) were fabricated using cobalt selenide (CoSe2)/graphene sheets using facile hydrothermal technique. The Pt free counter electrode (CE) was systematically investigated their physico-chemical properties by using SEM, TEM, XRD, Raman, UV, PL, XPS and BET analysis. Under typical AM 1.5G illumination, the DSSC based on the CoSeSe2 counter electrode achieves a maximum PCE of 12.2 % (Jsc = 22.3 mA/cm2, Voc= 810 mV, and FF= 0.71), which is 5.8 times higher than that of conventional Pt-based DSSC. The improved electro catalytic activity and photo conversion efficiency of the CoSeSe2/graphene CE is due to prevent the recombination of electron-hole pair and extended the visible light absorption of composite samples.

Enhanced catalytic performance of Cu2ZnSnS4/MoS2 nanocomposites based counter electrode for Pt-free dye-sensitized solar cells

Low abundance, high cost and corrosiveness towards the liquid electrolyte is the main limitation of Platinum (Pt) as a counter electrode (CE) in dye-sensitized solar cells (DSSCs) in spite of its excellent electrochemical properties. The present study focuses to enhance the electrochemical properties of CZTS by compositing it with MoS2 towards the replacement of Pt. Pure CZTS, pure MoS2, CZTS/MoS2 nanocomposites are synthesized by hydrothermal method, then characterized and compared to analyze their properties. The outcomes of characterizations techniques from XRD, Raman, XPS, SEM, EDS and TEM confirmed the formation of CZTS/MoS2 nanocomposites. The electrochemical characterizations and Impedance analysis of the pure CZTS, pure MoS2 and CZTS/MoS2 are compared. Results showed enhanced catalytic property and lower charge transfer resistance for the CZTS/MoS2 nanocomposites. Nanocomposite with 8 wt% of MoS2 in CZTS exhibited higher carrier concentration of 6.126 × 1018 cm−3, higher mobility of 5.03 cm2Vs−1 and lower resistivity of 2.62 Ωcm compared to CZTS and other nanocomposites. Electrical conductivity and catalytic activity were improved with increase in the wt% of MoS2 in the Cu2ZnSnS4/MoS2 nanocomposites. DSSC device fabricated by interpolating di-tetrabutylammonium cis-bis(isothiocyanate)bis(2,2″-bipyridyl-4,4′dicarboxylato) ruthenium (II) (N719) dye-loaded titanium dioxide (commercial P25 TiO2 as photoanode) and with CZMo8 (as CE) using iodine/iodide as a liquid electrolyte exhibited the maximum open circuit voltage of 720 mV, a short circuit current of 8.45 mA/cm2, a fill factor of 0.66, and a power conversion efficiency of 4.07%.

Graphene Quantum Dots Embedded in NiCo2S4/MWCNT Nanocomposite as a Promising Candidate for Supercapacitors and I3– Reduction in Dye-Sensitized Solar Cells

Nickel Cobalt Sulfide (NCS) along with Graphene Quantum Dots (GQDs) and Multiwalled Carbon Nanotubes (MWCNTs) are used here for the Counter Electrode (CE) to replace the conventional Pt in a Dye- Sensitized Solar Cell (DSSC). The usefulness of this system in the design of supercapacitors is also investigated. Various analytical tools are used to explore the crystallinity, morphology, and valence states of the synthesized nanocomposites. A short circuit current (JSC) of 11.57 mA/cm2, an open-circuit voltage (VOC) of 0.74 V, and a power conversion efficiency (PCE) of 5.84% are achieved for GQDs embedded NCS/MWCNT nanocomposite which is 39% higher compared to the pristine NCS (3.52%). The obtained PCE is compared with the standard Pt CE (∼6.88%) based DSSCs. Besides, cyclic voltammetry and galvanostatic charge–discharge characteristics are also done to study the supercapacitor performance. The specific capacitance of 448 F/g and 361 F/g at 2 A/g have been achieved with and without a GQDs implanted NCS/MWCNT nanostructure. This research suggests that GQDs implanted NCS/MWCNT is not only a Pt-free DSSC replacement but also has storage capability.

Characterization of reduced graphene oxide/macrocyclic Fe(II) complex nanocomposite as the counter electrode in Pt-free dye-sensitized solar cells

In this study, we have developed a composite material by using graphene oxide (GO) and a macrocyclic Fe metal complex as a counter electrode (CE) in dye-sensitized solar cells (DSSCs). Different ratios of GO and macrocyclic metal complex have been used and analyzed using various characterization techniques (field emission scanning electron microscopy, Fourier transform infrared spectroscopy, and energy dispersive X-ray spectroscopy). These results showed that there is complete reaction between GO and macrocyclic Fe complex and the macrocyclic complex has been grafted evenly onto the surface of graphene. Electrochemical catalytic capacity of the CE’s has been enhanced due to the redox capacity of the macrocyclic metal complex, high surface area and high conduction of graphene. This CE undergoes various studies (current density-voltage, incident photo-to-current conversion efficiency, and electrochemical impedance spectroscopy) and results have been compared with that of conventional platinum CE. CE’s made of GO and macrocyclic Fe complex show better efficiency compared to the traditional platinum counter electrode. Thus, this composite material can be used as a CE for the DSSC because of its less cost and excellent performance. It is an ideal replacement for the expensive platinum CE.