Counter Electrode For Dye-sensitized Solar Cells Research Articles

Synthesis of CuCo2S4 nanosheets and its application in dye-sensitized solar cells

CuCo2S4, a ternary sulfide and an eco-friendly thiospinel that occurs naturally as a mineral named Carrollite, has been synthesized successfully in ambient conditions at low temperatures using ultrasonication. It has yet to be reported, but the nanosheet structure obtained from the ultrasonication synthesis method employed as a counter electrode in the dye-sensitized solar cells (DSSCs) has been demonstrated. The purity, crystallinity, morphology, and structure were explored thoroughly through the medium of XRD, SEM, TEM, SAED, and EDAX, and along with this, the presence of metal sulfide bond was investigated with the FT-IR and Raman spectra, which altogether confirmed the formation of CuCo2S4 nanosheet. The as-prepared nanosheets of CuCo2S4 have shown excellent homogeneity, as expected. Also, the presence of sulfur in the synthesized CuCo2S4, which is a highly polarizable atom and of a smaller size exhibiting a higher surface area, demonstrates higher electrocatalytic activity when fabricated as a counter-electrode in DSSCs by providing an incredible short circuit current density of 31.05 mA cm−2, open circuit potential of 735 mV with good fill factor value which altogether resulted in the power conversion efficiency of 10.21 % nearer to DSSC fabricated with Platinum counter electrode under the same conditions.

Nitrogen and sulfur co-doped porous carbon obtained from direct carbonization of a renewable biomass for counter electrode of efficient dye-sensitized solar cells

It is highly necessary to fabricate cost-effective counter electrode for promoting the development and practical deployment of dye-sensitized solar cells (DSSCs). Herein, nitrogen and sulfur co-doped porous carbon (NSPC) is prepared through directly carbonizing a renewable biomass, Eupatorium fortunei Turcz., and used as an alternative to expensive Pt to fabricate low-cost counter electrode for high-performance DSSCs. Scanning electron microscopy and N2 adsorption analyses demonstrate that the obtained carbon sample displays a hierarchical pore structure containing macropore channels and well-developed mesopores formed on the wall of macropore channels. X-ray photoelectron spectroscopy measurements suggest that nitrogen and sulfur atoms are doped in the framework of as-prepared carbon sample. These favorable characteristics endow the obtained NSPC counter electrode with a superior electrocatalytic performance. Consequently, the assembled DSSC with NSPC counter electrode shows an efficiency of 8.25%, nearly matching the efficiency of the cell with conventional Pt counter electrode.

Oxygen enriched PAni-based counter electrode network toward efficient dye-sensitized solar cells (DSSCs)

Dye-sensitized solar cells (DSSCs) have great potential as a renewable energy technology assisting combat climate change due to its low cost, adaptability, and sustainability. Oxygen plasma ion doping is a promising strategy to improve the capacity of a low-cost, platinum-free counter-electrodes (CEs) to absorb photons and drive high-performance DSSCs via generating an abundance of active absorption sites. In this instance, novel PAni–ZnO (PZ) composite layers were designed as a CE material and received various in-situ oxygen plasma dosages, including 0, 2, 4, 6, 8, and 10 min, to improve their physiochemical and microstructural feature for the first time, to the best of our knowledge. Physical evaluations of the microstructure, porosity, morphology, contact angle, roughness, electrical, and optical, electrochemical impedance spectroscopy (EIS) features of CEs were conducted in along with an evaluation of J–V variables. Compared to pristine CE substance, the surface nature of the modified hybrids was gradually enhanced as the plasma level rose, reaching an optimum after 8 min (i.e. 0.2 µm for average pore size and average roughness Ra = 7.21 µm). Expanded plasma treatment doses also improved PV cell performance even further: after 4 min at a plasma level, η = 5.41% was obtained, and after 6 min in a oxygen plasma environment, η = 5.81% was obtained. Mixing high energetic plasma ions increased the mobility of charge carriers in PAni composites along with lowered charge carrier recombination through generating an environment that was conducive to charge dissociation. Therefore, longer lifespans and more effective charge transfer inside the photovoltaic cell as a consequence of the increased mobility less resistive losses. In this respect, following 8 min of plasma surface modification of the PZ CE, the optimized efficiency of 6.31% and Jsc of 15.6 mA/cm2 were obtained. The improvement in efficiency equated to a proportion growth of 77% versus a pristine one. This gain was explained by the reality that suffusing a quantity of oxygen plasma free radicals into the PAni system developed continuous channels that enabled the mixture to move electrons more rapidly, hence raising the photovoltaic efficiency. Overall, this study highlights the advantages of regulating heteroatom species and their co-doping, offering a new perspective for the application of heteroatom-doped CE in DSSCs.

Honeycomb shaped carbon dopped 1T-2H-MoS2 heterojunction counter electrode with high short current for dye sensitized solar cells

Recent years have witnessed energy crises in various regions and the utilization of new energy is crucial. Dye-sensitized solar cells (DSSCs) are the third generation of photovoltaic cells that are expected to be more cost-effective than other types of solar cells. In this work, we report the synthesis of 1T-2H-MoS2/honeycomb shaped carbon (HSC) heterojunction composite counter electrodes for DSSCs via adding porous carbon in the facile hydrothermal method. The effects of HSC on the morphology, structure, electrochemical and photoelectric conversion properties of the 1T-2H-MoS2/HSC composites were investigated systematically. Both the results of electrochemical and photoelectric measurement suggest the excellent performance of the reduction of I3- and the regeneration of dye. The whole cell assembled with the MoS2/HSC-5.0 counter electrode achieved a short current density 22.24 mA∙cm−2 and a power conversion efficiency (PCE) of 8.42 %, which is significantly higher than that of the pure MoS2 electrode (5.89 %) and Platinum electrode (6.76 %), implying the MoS2/HSC-5.0 composite is a promising candidate for counter electrodes catalyst of DSSCs.

Improving the properties of Pt-free dye-sensitized solar cells (DSSCs) by PEDOT:PSS/SnSe-rGO-based counter electrode: Exploring the electrocatalytic activity

In this study, we synthesized SnSe-rGO/PEDOT nanostructures and evaluated their potential as counter electrodes in dye-sensitized solar cells (DSSCs). Developing cost-effective counter electrodes for DSSCs is a critical challenge, as traditional designs often rely on platinum, an expensive material. Therefore, identifying alternative materials that are both effective and durable is of significant interest. We characterized the structural and morphological properties of the synthesized nanostructures using XRD, Raman spectroscopy, and FESEM. Additionally, we investigated their electrochemical and electrocatalytic performance through EIS, CV, and Tafel measurements. The solar cells fabricated with SnSe-rGO/PEDOT:PSS counter electrodes achieved an efficiency of 8.78 %, a notable improvement over the 8.13 % efficiency observed in cells with Pt counter electrodes. These findings suggest that SnSe-rGO/PEDOT nanostructures hold great promise as a more affordable and efficient alternative to platinum in DSSCs.

Rational Design of Facile and Low‐Cost Construction of Carbon‐Based Dye‐Sensitized Solar Cells using Garcinia Mangostana L. as a Photosensitizer

Research on solar cell devices is not only always related to how to obtain high power conversion efficiency (PCE), but also other factors need to be fully considered, such as the cost and their ecofriendliness. In this present research, a low‐cost and ecofriendly dye‐sensitized solar cell (DSSC) is being developed using a graphite‐based nanocomposite and an unusual plant extract (Garcinia mangostana L.) as the dye photosensitizer. A rational design on how to use graphite as a photoanode and counter electrode (CE) in DSSC is carried out by combining the graphite with ZnO and multiwalled carbon nanotube (MWCNT), respectively. It is observed that graphite acts as a matrix for ZnO and MWCNT to make these nanocomposites have very appropriate optoelectronics and catalytic properties compared to the control sample. Therefore, they could serve as an excellent photoanode and CE, respectively. It is also expected that the anthocyanin absorption in Garcinia mangostana L. dye which is found in the visible light range can efficiently absorb photons, thus supporting the enhancement of photovoltaic performance of the DSSC. The generated voltage (V) and current (I) from light irradiation using commercial lamps are higher compared to halogen lamps, indicating that the obtained DSSC has potential as indoor powered devices. It is believed that our study can shed light on the development of DSSC using low‐cost material graphite as the main component for the realization of low‐cost DSSC devices.

Attaining promising efficiency through a Quasi-Solid-State symmetrical supercapacitor and Dye-Sensitized solar cell counter electrode utilizing bifunctional Nitrogen-Doped microporous activated carbon

This study addresses the imperative need for high-performance and sustainable energy storage and conversion technologies by leveraging the unique properties of nitrogen-doped porous carbon (N@WnAC) derived from the waste walnut shells (WnS). In the realm of supercapacitors, the N@WnAC demonstrates remarkable performance in a three-electrode system, showcasing a high specific capacitance value of 276.7 Fg−1 at 1 Ag−1, outstanding stability (96.6 %, 5000 charge–discharge cycles) and favourable rate capability (68.8 % at 10 Ag−1). Moreover, a quasi-solid-state symmetrical supercapacitor (N@WnAC//N@WnAC) is fabricated with PVA/H2SO4 gel electrolyte, underscores outstanding performance by delivering high capacitance (126.2 Fg−1 at 0.5 Ag−1), promising rate capability (71.8 % at 5 Ag−1), favourable long-term stability (93.3 %, 5000 charge–discharge cycles), and faster charge–discharge kinetics compared to conventional counterparts. At the same time, N@WnAC//N@WnAC delivers a high energy density (42.27 Whkg−1 at 0.5 Ag−1) that was retained up to 23.96 Whkg−1 even at 5 Ag−1. Simultaneously, the study explores the potential of N@WnAC as a counter-electrode (CE) in dye-sensitized solar cells (DSSC). The obtained results underscore that unique nitrogen doping enhances the electrocatalytic activity, leading to improved electron transfer kinetics and overall cell performance. Moreover, the N@WnAC CE-based DSSC delivers a promising overall solar-to-electrical conversion efficiency of 5.84 %.

Density functional theory study of cobalt sulfide as a counter electrode material for dye-sensitized solar cells

Abstract Dye-sensitized solar cells (DSSCs) are viewed as potential substitutes for traditional silicon-based solar cells due to their affordability, impressive performance in low-light conditions, eco-friendly energy production, and adaptability in solar product integration. The use of noble metals such as platinum as counter electrodes in DSSCs was initially limited by their high cost; however, cobalt sulfide has been recognized as a viable alternative due to its abundance, non-toxic properties, and cost-effectiveness. In this work, the crystal structure, electronic, optical characteristics and electrocatalytic activity of the tetragonal phases of cobalt sulfide are investigated through density functional theory with a quantum espresso package. The results obtained for the lattice parameter are a = b = 3.53 Å and c = 4.80 Å. The generalized gradient approximation and hybrid exchange correlation function yield bandgaps of 1.63 and 1.69 eV, respectively, which are consistent with the reported experimental values. An analysis of the density of states and the projected density was carried out to validate the accuracy of the calculated band gaps. Additionally, significant information was obtained from the optical properties through the calculation of the dielectric function. The findings reveal real and imaginary static dielectric constants of 11.85 and 0.13, respectively. Furthermore, the measured absorption and conductivity spectra exhibit promising attributes in the UV–visible range and good electrical conductivity. Moreover, the electrocatalytic activity was studied to analyze the adsorption energy of CoS and the electrolyte. Generally, the calculated electronic and optical properties of CoS crystals indicate their potential application as counter electrodes in dye-sensitized solar cells.

Extraction and Characterization of Silicon Dioxide from Coal Fly Ash as Counter Electrode Material in Dye-Sensitized Solar Cells (DSSCs)

The counter electrode in DSSCs must be made of a material with various advantageous chemical and physical characteristics to guarantee the cell’s efficient functioning and cost efficiency. Coal fly ash is recognized for its substantial silicon dioxide (SiO2) content and other minerals and metals. This paper provides a detailed analysis and description of extracting and characterizing SiO2 from coal fly ash. This extraction aims to utilize SiO2 as a material for the counter electrode in DSSCs. The extraction procedure of SiO2 from coal fly ash involves a multi-step process that entailed the utilization of acid leaching using hydrochloric acid 1 M at 90°C for 4 h, which was subsequently followed by precipitation using NaOH 3 M at 90°C for 4 h to separate SiO2. The SiO2 gel was cleaned of contaminants with hot distilled water and dried at 110°C for 12 h. The SiO2 that was obtained was analyzed utilizing a range of analytical techniques to evaluate its structural, morphological, chemical, and optical properties. The X-ray diffractometer (XRD) examination revealed that the crystal structure of coal fly ash consisted of quartz, corundum, hematite, lime, and periclase. The SiO2 that was obtained exhibited a crystal structure that was both cubic and triclinic. The morphology is visualized using a scanning electron microscope (SEM). The study using atomic absorption spectroscopy revealed that the coal fly ash contained 52.91% SiO2, whereas the extracted SiO2 had a purity of 91.20%. The UV-Vis spectrophotometry investigation revealed that the SiO2 exhibited absorbance spectra with a wide band gap of 4.17 eV, whereas the coal fly ash had absorbance spectra of 3.37 eV.

Fabrication of CoM (M= Ni, Cu) alloys modified carbon electrocatalysts by pyrolysis of dual-metal-site metal-organic frameworks for efficient dye-sensitized solar cells

The regulation of interface properties of multi-component transition metals in carbon-based catalyst has been an effective method to boost the electrochemical performance of counter electrode (CE) catalysts for dye-sensitized solar cells (DSSCs). Herein, CoNi-metal-organic framework (MOF) and CoCu-MOF are fabricated through introducing Ni and Cu into the stable Co-MOF, and used as sacrificial precursor in the followed pyrolysis-alloying process. And then, the target product CoM (M=Ni, Cu)/N-doped polyhedron-like carbon (NC) are successfully obtained, in which CoNi and CoCu alloy nanoparticles are uniformly dispersed on the N-doped carbon skeleton. Such MOFs-derived carbon matrix can not only supply as conductive network, but also isolate the alloy nanoparticles to avoid agglomeration, ensuring more effective active sites. Meanwhile, the built-in electric field generated by the Mott-Schottky interface effect of CoM/NCs could regulate the electronic structure inside the catalysts, resulting in faster electron transfer ability. Significantly, the reduced work function due to the introduction of Cu atoms leads to stronger self-driven electron transfer at the heterogeneous interface of CoCu/NC, which helps to improve reaction activity and electrocatalytic efficiency. Among the tested catalysts, CoCu/NC displays a more satisfying power conversion efficiency (PCE) of 7.60 % when assembled into CE of DSSC, also superior to 7.19 % of Pt.

Novel 2D heterostructure composites of V2C MXene/TiO2 and graphene/TiO2 for platinum replacement in dye-sensitized solar cells

This study evaluates the potential of V2C MXene/TiO2 and Graphene/TiO2 composites as alternatives to platinum for counter-electrodes in dye-sensitized solar cells (DSSCs). V2C MXene was synthesized by selectively etching the aluminum layer from V2AlC MAX phase powder, resulting in multilayered V2C MXene. The layered morphologies of MXene and graphene were confirmed via Scanning Electron Microscopy (SEM), while their crystalline structures were validated using X-ray diffraction (XRD) analysis. SEM analysis confirmed the delaminated layered structure of graphene and the distinct layers of V2C MXene. XRD findings showed that MXene has significantly greater interlayer spacing than graphene, offering more catalytic sites for charge injection. Electrocatalysts were prepared by incorporating TiO2 paste with MXene and graphene, with TiO2 serving as a binder. These composites were then employed as counter-electrode materials in dye-sensitized solar cells. The MXene-based counter electrode achieved a photoconversion efficiency of 1.625 %, surpassing graphene-based (1.149 %) and Pt-based (1.567 %) counterparts under standard illumination. The efficiency of cells was meticulously characterized over an extended period. The results indicated that the efficiency of these cells remained stable over time. This stability suggests that MXene/TiO2 and Graphene/TiO2 based catalysts are robust and do not degrade with time.

A Bi2Te3 topological insulator/carbon nanotubes hybrid composites as a new counter electrode material for DSSC and NIR photodetector application

Two-dimensional layered bismuth telluride (Bi2Te3), a prominent topological insulator, has garnered global scientific attention for its unique properties and potential applications in optoelectronics and electrochemical devices. Notably, there is a growing emphasis on improving photon-to-electron conversion efficiency in dye-sensitized solar cells (DSSCs), prompting the exploration of alternatives to noble metal catalysts like platinum (Pt). This study presents the synthesis of Bi2Te3 and its hybrid nanostructure with single-wall carbon nanotubes (SWCNT) via a straightforward hydrothermal process. The research unveils a novel application for the Bi2Te3-SWCNT hybrid structure, serving as a counter electrode in platinum-free DSSCs, facilitating the conversion of triiodide (I3−) to iodide (I−) and functioning as an active electrode material in a photodetector (n-Bi2Te3-SWCNT/p-Si). The resulting DSSC employing the Bi2Te3-SWCNT hybrid counter electrode achieves a power conversion efficiency (PCE) of 4.2 %, a photocurrent density of 10.5 mA/cm2, a fill factor (FF) of 62 %, and superior charge transfer kinetics compared to pristine Bi2Te3 based counter electrode (PCE 2.1 %, FF 34 %). Additionally, a spin coating technique enhances the performance of the n-Bi2Te3-SWCNT/p-Si photodetector, yielding a responsivity of 2.2 AW−1, detectivity of 1.2 × 10−3 and enhanced external quantum efficiency. These findings demonstrate that the newly developed Bi2Te3-SWCNT heterostructure enhances interfacial charge transport, electrocatalytic performance in DSSCs, and overall photodetector performance.

Synergistic effect in ZIF-67/MoS2 entrenched MWCNT photo (electro) catalyst for degradation of tetracycline and alternative to Pt counter electrode in dye-sensitized solar cells

Photocatalytic water purification is an effective environmental protection approach for removing hazardous chemicals in water, besides solar energy conversion is a trustworthy and sustainable choice for the future due to rising energy demands. The present research focus is on synthesis of Metal-Organic Framework (MOF) based composite, Zeolitic Imidazolate Framework-67/Molybdenum Disulfide (ZIF-67/MoS2) entrenched Multi-Walled Carbon Nanotubes (MWCNT) as a catalyst for photodegradation of tetracycline (TC), as well as substitute for Pt counter electrode in Dye-Sensitized Solar Cell (DSSC). The crystalline structure, optical response, shape, porosity, quantum states, and chemical configuration were determined using X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Ultraviolet-Visible Diffuse Reflectance Spectroscopy (UV-DRS), Photoluminescence spectroscopy (PL), Transmission Electron Microscopy (TEM), Brunauer-Emmett-Teller (BET), and X-ray Photoelectron Spectroscopy (XPS), respectively. The degradation efficiency of ZIF-67/MoS2/MWCNT catalyst under effect of operational parameters namely, photocatalyst dosage, solution pH, coexisting ions, TC concentrations and irradiation time were studied consecutively. ZIF-67/MoS2/MWCNT composite achieved 96.1 % degradation efficiency of TC under white light irradiation. Interestingly, when utilized as a counter electrode in DSSCs, this composite-based electrode delivered the highest Power Conversion Efficiency (PCE) of 3.86 % with a short-circuit current density (JSC) of 7.54 mA cm−2 and open-circuit voltage (VOC) of 0.79 V. The observed enhancement is attributed to lesser peak-to-peak separation (EPP), lower electron lifetime, lower charge transfer resistance (RCT) and higher exchange current density (J0). Based on these findings, ZIF-67 inclusion in MoS2/MWCNT composite is not only an effective catalyst for water treatment but also a good catalyst for I3− reduction in DSSCs.

Enhanced efficiency and stability of dye-sensitized solar cells utilizing FeCo2S4 nanowires as Pt-free counter electrodes

Replacing traditional Pt-based counter electrodes with low-cost and highly stable materials is crucial for the development of commercially viable dye-sensitized solar cells (DSSCs). In this study, we synthesized a ternary Pt-free FeCo2S4 nanowire (NW)-based sulfide electrocatalyst by a three-step solvothermal method. This material was then used as a counter electrode in DSSCs to facilitate the reduction of triiodide species. The formation of FeCo2S4 NW was confirmed by various characterization techniques such as X-ray diffraction, energy dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy. Scanning electron microscopy analysis revealed the structure of the nanowires. Electrochemical studies, which included cyclic voltammetry, electrochemical impedance spectroscopy and Tafel polarization methods, revealed the excellent stability, superior electrocatalytic activity and remarkable kinetics of FeCo2S4 NW in the reduction of triiodide to iodide. Photovoltaic measurements of the fabricated DSSCs yielded a power conversion efficiency (PCE) of 7.88 % for the FeCo2S4-based devices, outperforming the control device made of Pt (PCE=7.45 %). This improvement was primarily due to the increase in short-circuit current density (JSC), thanks to the lower charge transfer resistance (RCT) of FeCo2S4 NW (JSC=15.23 mA/cm2; RCT=5.54 Ω cm2) compared to Pt (JSC=14.12 mA/cm2; RCT=7.07 Ω cm2). In addition, the FeCo2S4 NW-based solar cells exhibited excellent stability and maintained their high PCE value even after 10 days of aging under ambient conditions, while Pt-based DSSCs showed a 3 % decrease from their initial PCE value. This FeCo2S4 NW counter electrode proves to be an excellent alternative to Pt, and the presented results provide valuable insights for the development of cost-effective and highly stable DSSCs.

Iron-nickel-cobalt selenide nanoparticles as an efficient and transparent counter electrode for dye-sensitized solar cells

In this study, we developed a quaternary metal selenide (Fe0.35Ni0.11Co0.19Se) counter electrode (CE) material, grown onto fluorine-doped tin oxide, for dye-sensitized solar cells (DSSCs) using the potential-reversal electrochemical deposition technique at ambient conditions. Under optimized conditions, the Fe0.35Ni0.11Co0.19Se CE exhibited excellent electrocatalytic activity in the I-/I3- redox reaction with the average transmittance of 78.85 %. The additional valence states of Fe in the Ni0.3Co0.3Se electrode material further enhanced the catalytic activity during the electrochemical redox process. The DSSC employing this electrocatalytically active CE realized a power conversion efficiency of 7.73 %, surpassing the efficiency of both Pt and Ni0.3Co0.3Se CEs-based DSSCs (7.23 % and 7.23 %, respectively). This electro-preparation method offers a simpler and more cost-effective fabrication process for CE design, demonstrating a good potential for replacing expensive platinum CEs in DSSCs.

Nanocomposites of Co-NiS/GO as a Versatile Catalyst: Enabling Platinum-Free DSSC Counter Electrodes and Enhancing Organic Dye Degradation

This study presents the synthesis of a nanocomposite intended to serve as a counter electrode in dye-sensitized solar cells (DSSCs), replacing platinum electrodes, as well as functioning as a nanocatalyst for organic dye degradation. Graphene oxide was synthesized using a modified Hummers method, and cobalt-doped nickel sulfide on graphene oxide (Co-NiS/GO) was prepared via hydrothermal synthesis. The samples underwent characterization through various testing methods. X-ray diffraction analysis revealed a hexagonal structure with a crystallite size of 30 nm. Field-emission scanning electron microscopy/energy-dispersive X-ray images showed a cornflake-like structure, with elements such as cobalt, nickel, sulfur, carbon, and oxygen present. Chemical valence states were confirmed through X-ray photoelectron specteroscopy analysis. The power conversion efficiency of the Co-NiS/GO counter electrode in DSSCs was investigated, with parameters such as open-circuit voltage, short-circuit current density, fill factor, and power conversion efficiency calculated to be 8.6032 mV, 0.5484 mA cm−2, 61, and 2.83%, respectively, based on I-V studies. Furthermore, the developed Co-NiS/GO nanocomposite was assessed for its photo catalytic dye degradation capabilities using malachite green (MG), achieving a degradation rate of approximately 96% within 180 min.

Boosting the performance of dye-sensitized solar cells by employing Li-substituted NiO nanosheets as highly efficient electrocatalysts for reduction of triiodide

Dye-sensitized solar cells (DSSCs) exhibit considerable potential as a promising technology, particularly when addressing the challenge of replacing the costly Platinum (Pt) counter electrode (CE) with economically viable and chemically stable CE materials. This study examines the use of two-dimensional hexagonal-shaped nickel oxide nanosheets substituted with varying mol% of lithium (1, 3, and 5 %) (Li (1–5%)-NiO NSs) as the counter electrodes (CEs) for DSSCs. The facile hydrothermal method was employed for the preparation of NiO and Li (1–5 mol%)-NiO samples. The BET analysis of NiO and Li (1–5%)-NiO indicates that higher concentrations of Li1+ ions in Ni2+ ions sites lead to an increase in the overall surface area of NiO. This leads to an elevated number of exposed electrocatalytic active sites which resulted in enhancing the rate of reduction of I3− ions. The cyclic voltammetry (CV) result of 5 mol% of Li substituted NiO (5-LNO) shows outstanding electrocatalytic activity towards the redox reaction of I3−/I− redox mediator among the as-prepared CEs. The DSSCs assembled with 5-LNO CE show an excellent power conversion efficiency (η) of 5.84 % with short-circuit current (Jsc) of 18.76 mAcm−2, and open-circuit voltage (Voc) of 0.80 V which is higher than Pt-based CE (η of 4.05 % with Jsc of 10.16 mAcm−2, and Voc of 0.69 V). The DSSCs fabricated with 5-LNO CE exhibit excellent photovoltaic performance because of their high active surface area and enhanced electrical conductivity. The 5-LNO CE has low cost, significant electrocatalytic activity, less toxicity, and superior device efficiency than NiO, other Li (1–3%)-NiO, and Pt CEs, making it a suitable candidate for Pt-free DSSCs application.

Analysis of nickel oxide as a counter electrode for dye-sensitized solar cells using OghmaNano software

Dye-sensitized solar cells (DSSCs), a promising green technology, convert solar energy into electricity more cost-effectively than traditional solar cells. While platinum (Pt) is commonly used in DSSCs, its high cost and toxicity limit practical applications. Recent research aims to develop low-cost counter electrodes with high efficiency. Nickel oxide (NiO), a p-type semiconductor with a wide bandgap, good transmittance, and suitable work function, emerges as a potential alternative for counter electrode of DSSCs. In this work, DSSCs with NiO of thicknesses varying from 100 nm to 1000 nm were simulated to determine its influence on photovoltaic performance using OghmaNano software. The structure of simulated solar cells consists of NiO as counter electrode, zinc oxide (ZnO) as photoanode, N719 as dyes, electrolyte as charge carrier transport, and fluorine-doped tin oxide (FTO) as a contact layer. There are five data of NiO used as an active layer. From the simulation results, NiO-doped gold exhibits the highest power conversion efficiency (PCE) of 15.95% at a thickness of 700 nm, while pure NiO shows the lowest PCE with 4.53% at a thickness of 600 nm. These results have demonstrated that NiO can replace Pt as a counter electrode for DSSCs and doping plays a vital role in increasing efficiency.

Active carbon derived from rice husk as sustainable substitutes for costly platinum electrodes in dye-sensitized solar cells

Significant financial and environmental challenges are associated with using platinum electrodes as counter electrodes (CEs) in dye-sensitized solar cells (DSCs). This work uses rice husk, an agricultural waste, to create active carbon that is appropriate for DSC CEs in response to these difficulties. A simple spray pyrolysis technique created activated carbon obtained from rice husks. The DSC employing activated rice husk carbon as the CE demonstrated a conversion efficiency of 6.06%, slightly lower than the 8.21% efficiency achieved with a platinum electrode-based cell. However, this performance gap is overshadowed by the substantial cost reduction enabled by the utilization of low-cost activated carbon compared to noble metal alternatives. This result introduces promising avenues for investigating the use of agriculturally derived carbon materials as workable and affordable options for platinum CEs in DSCs, thereby contributing to the sustainable advancement of photovoltaic systems. Even though the performance of DSC that uses activated carbon derived from rice husk in CE is slightly lower than its counterparts based on platinum, the cost reduction due to the use of low-cost activated carbon with noble metal is significant.

Design highly effective B or N doped mesoporous carbon fibers catalysts for I3-/I- redox couple regeneration in carbon-based dye-sensitized solar cells

Construction of mesoporous structure and improving the conductivity of carbon counter electrode are feasible paths to enhance the catalytic activity in dye-sensitized solar cells (DSCs) toward the I3-/I- redox couple regenerating (IRR). Herein, mesoporous carbon fiber (PCf) has been first synthesized and the DSCs using PCf counter electrode results in a power conversion efficiency (PCE) of 7.12%, significantly surpassing the PCE of 6.01% generated by the DSCs with carbon fiber (Cf) counter electrode without mesoporous structure. Additionally, doping with heteroatoms B or N can further enhance the catalytic performance of PCf. Consequently, B or N doped Cf (BPCf or NPCf) counter electrode-based DSCs achieve high PCE values of 8.43% and 7.96%, respectively, demonstrating PCE improvements of 40.3% and 32.4%. This enhancement in catalytic activity for IRR in DSCs can be first attributed to the increased specific surface area of Cf which can provide more catalytic activated sites. Meanwhile, the enhanced conductivity of PCf by heteroatoms B or N doping is also an important factor for the improved catalytic activity. This work is expected to provide potential path to enhanced the catalytic activity of carbon counter electrode in DSCs toward IRR.