- 标题
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- 实验方案
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Hollow hierarchical structure Co0.85Se as efficient electrocatalyst for the triiodide reduction in dye-sensitized solar cells
摘要： The exploration of nonprecious metal-based electrocatalysts with high efficiency for the triiodide reduction is critical for the practical applications of the dye-sensitized solar cells. Herein, we develop a facile one-step hydrothermal method to synthesize hollow hierarchical structure Co0.85Se. Under the methanol-water reaction system, the product named as hollow hierarchical structure Co0.85Se-M has the largest specific surface area (215.36 m2 g?1) and the best crystallinity than other products obtained from other alcohol-water reaction systems. When this electrocatalyst is applied as a counter electrode for the dye-sensitized solar cells, it exhibits a small peak-to-peak separation (Epp, 97 mV) for the reduction of I3?/I? redox couple. It is found that the catalytic activity of Co0.85Se is closely dependent on the crystallinity. Moreover, the reactivity pathway is identified by density functional theory, which confirms that triiodide is reduced to iodide ion on Co0.85Se with a smaller energy barrier (～0.65 eV) than on Pt (～1.18 eV). Both experimental and theoretical results demonstrate Co0.85Se-M as an ideal counter electrode material for the dye-sensitized solar cells with a higher power conversion efficiency (8.76%) than Pt counter electrode (7.20%).
关键词： Dye-sensitized solar cells,Hollow hierarchical structure,Cobalt selenides,Electrocatalytic activity,Triiodide reduction
更新于2025-11-21 11:03:13
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Synthesis of CoNi bimetallic alloy nanoparticles wrapped in nitrogen-doped graphite-like carbon shells and their electrocatalytic activity when used in a counter electrode for dye-sensitized solar cells
摘要： Nanoparticles of the bimetallic alloy CoNi wrapped in nitrogen-doped graphite-like carbon shells and dispersed on nitrogen-doped graphite-like carbon sheets (CoxNi1?x@NC) were synthesized by calcining CoNi metal–organic frameworks that were prepared through a facile solvothermal reaction using various raw-material molar ratios Co:Ni and CoNi:ethylenedinitrilotetraacetic acid. After depositing CoxNi1?x@NC for use as a counter electrode film in dye-sensitized solar cells, it was found that the electrocatalytic activity of the CoxNi1?x@NC counter electrode towards triiodide reduction could be optimized by simply tuning the molar ratios (Co:Ni and CoNi:ethylenedinitrilotetraacetic acid) appropriately during CoxNi1?x@NC synthesis. Cells that utilized a CoxNi1?x@NC counter electrode exhibited strong chemical-composition-dependent photovoltaic performance. Under optimal conditions, the CoxNi1?x@NC counter electrode presented an impressive energy conversion efficiency of 3.58%, suggesting that it is a highly promising counter electrode for application in dye-sensitized solar cells. This counter electrode has the advantages that it is considerably less expensive than a Pt counter electrode and that it provides the basis for the design and preparation of other inexpensive and efficient counter electrodes to replace Pt.
关键词： Photovoltaic performance,Dye-sensitized solar cells,CoNi alloy bimetallic nanoparticles,Counter electrode,Electrocatalytic activity
更新于2025-11-14 17:04:02
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Monodispersed Nickel Phosphide Nanocrystals In Situ Grown on Reduced Graphene Oxide with Controllable Size and Composition as Counter Electrode for Dye-Sensitized Solar Cells
摘要： Owing to their abundance, low cost and excellent functional properties and catalytic activity, transition metal phosphides (TMPs) have been proposed in a broad range of energy conversion technologies. However, their challenging synthesis and moderate electrical conductivity has limited their implementation in real applications. Here, we detail a simple procedure to grow fully dispersed nickel phosphide nanocrystals (NCs) with controlled size, phase and composition on the surface of reduced graphene oxide (rGO). The resultant NixPy/rGO composites effectively combine a huge density of catalytic active sites from NixPy with the excellent conductivity of rGO, thus exhibiting highly improved electrocatalytic activities. NixPy/rGO composites were tested as counter electrode (CE) in dye sensitized solar cells (DSSCs), providing significantly improved performance over conventional Pt-based CEs. The incorporation of CEs based on Ni12P5/rGO composites allowed reaching power conversion efficiency up to 8.19%, well above those of DSSCs based Pt CEs (7.87%). According to DFT calculations, the outstanding electrocatalytic activity of Ni12P5/rGO as CE in DSSCs was associated with the exceptional I3ˉ adsorption capacity. These results prove that Ni12P5/rGO is a promising candidate to replace Pt as CE in DSSCs.
关键词： Reduced graphene oxide,Dye-sensitized solar cells,Nickel phosphide,Electrocatalytic activity,Monodispersed
更新于2025-09-23 15:21:01
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One-pot fabrication of mesoporous g-C3N4/NiS co-catalyst counter electrodes for quantum-dot-sensitized solar cells
摘要： The nickel sulfide (NiS) nanoparticles were anchored on the mesoporous graphitic carbon nitride (g-C3N4) by one-pot calcination with sulfur powder as sulfur source and pore-forming agent. It is the first attempt to use the g-C3N4/NiS as a counter electrode (CE) for quantum-dot-sensitized solar cells. The g-C3N4/NiS co-catalyst based on 0.74 wt% NiS loading for Sn2- reduction obtained a low interface charge transfer resistance (Rct) of 1.08 Ω. The power conversion efficiency of the QDSSC assembled with ZnSe/CdS/CdSe/ZnSe-sensitized TiO2 photoanode and g-C3N4/NiS CE is up to 5.64%, which is 3.05 times as high as that of pure g-C3N4 CE. The enhancement of cell efficiency is attributed to the synergistic effects of excellent morphology of g-C3N4 and its co-catalysis with NiS nanoparticles. The mesoporous architecture contributes a large specific surface area and fast electrolyte transfer channels, and the coupling of g-C3N4 with NiS promotes the transfer of charge between the interface g-C3N4/NiS and electrolytes. The presented strategy for fabricating mesoporous architecture with g-C3N4/NiS uses low-cost raw materials and a simple preparation method, which provides a feasible route to enhance the electrocatalytic activity of g-C3N4.
关键词： g-C3N4/NiS,electrocatalytic activity,mesoporous architecture,counter electrode,quantum-dot-sensitized solar cells
更新于2025-09-23 15:21:01
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An All Carbon Dye Sensitized Solar Cell: A Sustainable and Low-Cost Design for Metal Free Wearable Solar Cell Devices
摘要： Lightweight carbon electrodes are the new candidates for photovoltaic devices due to their temperature resistivity, ease of fabrication, and skin comfortability. Herein, a sustainable and facile strategy has been proposed for metal free all carbon dye sensitized solar cell (C-DSSC), assembled by stacking carbon front electrode (CFE) and carbon counter electrode (CCE). The CFE demonstrated adequate light transmittance (70-50%) while maintaining efficient photon absorption and charge separation mechanism due to dye coated TiO2 nanorods (P25-R). The graphene dip coated carbon counter electrode (Gr@CCE) possesses remarkable highly electro catalytic activity towards 3 /I ― I ― redox couple with low charge transfer resistance (RCT=0.79 ?). The sustainable design of C-DSSC attained ~6±0.5 % efficiency with high photocurrent density of 18.835 mA. cm-2. The superior performance of C-DSSC is accredited to its improved charge mobility, low internal resistance, and better interfacial electrode contact. The thickness of C-DSSC is ≤3 mm eliminates the need for rigid glass in DSSC.
关键词： Carbon,TiO2 nanorods,Dye sensitized solar cell,Graphene,Electrocatalytic activity
更新于2025-09-23 15:19:57
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Plasmonic-induced overgrowth of amorphous molybdenum sulfide on nanoporous gold: An ambient synthesis method of hybrid nanoparticles with enhanced electrocatalytic activity
摘要： Hybrid materials of earth abundant transition metal dichalcogenides and noble metal nanoparticles, such as molybdenum sulfide (MoSx) and gold nanoparticles, exhibit synergistic effects that can enhance electrocatalytic reactions. However, most current hybrid MoSx-gold synthesis requires an energy intensive heat source of >500 ○C or chemical plating to achieve deposition of MoSx on the gold surface. Herein, we demonstrate the direct overgrowth of MoSx over colloidal nanoporous gold (NPG), conducted feasibly under ambient conditions, to form hybrid particles with enhanced electrocatalytic performance toward hydrogen evolution reaction. Our strategy exploits the localized surface plasmon resonance-mediated photothermal heating of NPG to achieve >230 ○C surface temperature, which induces the decomposition of the (NH4)2MoS4 precursor and direct overgrowth of MoSx over NPG. By tuning the concentration ratio between the precursor and NPG, the amount of MoSx particles deposited can be systematically controlled from 0.5% to 2% of the Mo/(Au + Mo) ratio. Importantly, we find that the hybrid particles exhibit higher bridging and an apical S to terminal S atomic ratio than pure molybdenum sulfide, which gives rise to their enhanced electrocatalytic performance for hydrogen evolution reaction. We demonstrate that hybrid MoSx-NPG exhibits >30 mV lower onset potential and a 1.7-fold lower Tafel slope as compared to pure MoSx. Our methodology provides an energy- and cost-efficient synthesis pathway, which can be extended to the synthesis of various functional hybrid structures with unique properties for catalysis and sensing applications.
关键词： molybdenum sulfide,electrocatalytic activity,nanoporous gold,hydrogen evolution reaction,plasmonic
更新于2025-09-23 15:19:57
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SiNW/C@Pt Arrays for High-Efficiency Counter Electrodes in Dye-Sensitized Solar Cells
摘要： Modern energy needs and the pressing issue of environmental sustainability have driven many research groups to focus on energy-generation devices made from novel nanomaterials. We have prepared platinum nanoparticle-decorated silicon nanowire/carbon core–shell nanomaterials (SiNW/C@Pt). The processing steps are relatively simple, including wet chemical etching to form the silicon nanowires (SiNWs), chemical vapor deposition to form the carbon shell, and drop-casting and thermal treatment to embed platinum nanoparticles (Pt NPs). This nanomaterial was then tested as the counter electrode (CE) in dye-sensitized solar cells (DSSCs). SiNW/C@Pt shows potential as a good electrocatalyst based on material characterization data from Raman spectroscopy and X-ray photoelectron spectroscopy (XPS). Raman spectroscopy shows that the surface reactivity of the SiNW/C is increased by the decoration of Pt NPs. These data also show that the carbon shell included both graphitic (sp2 hybridization) and defective (sp3 hybridization) phases of carbon. We achieved the minimum charge-transfer resistance of 0.025 ? · cm2 and the maximum ef?ciency of 9.46% with a symmetric dummy cell and DSSC device fabricated from the SiNW/C@Pt CEs, respectively.
关键词： core–shell,defective carbon,electrocatalytic activity,dye-sensitized solar cells (DSSCs),counter electrodes (CEs),silicon nanowires (SiNWs)
更新于2025-09-16 10:30:52
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Nanostructured Ni-doped CuS thin film as an efficient counter electrode material for high-performance quantum dot-sensitized solar cells
摘要： High electrocatalytic activity and low charge transfer resistance are the key factors of coutner electrodes (CEs) for high-performance quantum dot-sensitized solar cells (QDSSCs). Hence, it is challenging and highly deisrable to fabricate the CEs with high catalytic activity and low charge transfer resistance for QDSSCs. To address these issues, here, we design and prepare a new catalytic electrode by doping of nickel (Ni) ion in CuS for use as CEs in QDSSCs. The Ni-doped CuS CEs are fabricated via a facile chemcial bath deposition method. Scanning electron microscope study reveals that the Ni-doped CuS exhibits the surface morphology of nanoparticles over nanoflake structrues, while the CuS delivers the nanoflake structures. The Ni-doped CuS provides abundant active sites for reduction of polysulfide redox couple, higher electrical conductivity and offers excellent pathways for electron transfer, which yields the high electrocatalytic activity and delivers the lower charge transfer resistance at the interface of CE/electrolyte. As a result, the TiO2/CdS/CdSe QDSSCs with Ni–CuS yield a power conversion efficiency (η) of 4.36% with short circuit current density (JSC) of 13.78 mA cm?2, open-circuit voltage (VOC) of 0.567 V, and fill factor (FF) of 0.558, which are much superior to that of device with CuS CE (η = 3.24%; JSC = 10.63 mA cm?2; VOC = 0.567; FF = 0.546) under one sun illumination (AM 1.5G, 100 mW cm?2). Present work determines that Ni-doped CuS could be a promising CE material for QDSSCs due to its high electrical conductivity, excellent electrocatalytic activity, and lower charge transfer resistance.
关键词： Charge transfer resistance,Nanostructured Ni-doped CuS,Quantum dot-sensitized solar cells,Counter electrode,Electrocatalytic activity
更新于2025-09-12 10:27:22
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Synthesis of MoS2–MoO2/MWCNTs counter electrode for high-efficient dye-sensitized solar cells
摘要： In this work, MoS2–MoO2 and MoS2–MoO2/MWCNTs counter electrodes (CEs) for dye-sensitized solar cells (DSSCs) were prepared by sulfurization of a one-pot hydrothermally obtained MoO2 film and MoO2/MWCNTs composite film on fluorine-doped tin oxide glasses at 500?°C for 2?h in argon atmosphere. The promoted MoS2 particles on a surface of MoS2–MoO2 and MoS2–MoO2/MWCNTs films were identified by X-ray diffraction to have a hexagonal structure. Morphology of MoO2, MoO2/MWCNTs, MoS2–MoO2, and MoS2–MoO2/MWCNTs CEs was studied using field emission scanning electron microscope and transmission electron microscope. Functional groups in MoS2–MoO2/MWCNTs sample were identified by Raman spectroscopy. Results of cyclic voltammetry and electrochemical impedance spectroscopy displayed a high electrocatalytic activity performance and low charge transfer resistance of MoS2–MoO2/MWCNTs CE as compared to those of MoO2, MoO2/MWCNTs, and MoS2–MoO2 CEs. Interestingly, the DSSC based on MoS2–MoO2/MWCNTs CE could provide the higher power conversion efficiency of 7.79% compared to that of 7.26% for Pt-based DSSC.
关键词： electrocatalytic activity,dye-sensitized solar cells,counter electrode,MoS2–MoO2,MWCNTs
更新于2025-09-12 10:27:22
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Electronic Structures and Catalytic Activities of Niobium Oxides as Electrocatalysts in Liquid Junction Photovoltaic Devices
摘要： Two types of nanosized niobium oxides and their composite: pseudo-hexagonal Nb2O5 (TT-Nb2O5), monoclinic NbO2 (M-NbO2) and the coexistence of TT-Nb2O5 and M-NbO2 (TT-Nb2O5/M-NbO2) are successfully synthesized through the urea-metal chloride route, and they exhibit excellent catalytic activity and photovoltaic performance in dye-sensitized solar cells (DSSCs). First-principles density function theory (DFT) calculations show that their catalytic activity is significantly influenced by their intrinsic electronic structures and properties. The lone-pair 4d1 electrons of Nb4+ in M-NbO2 enhance the Nb-I interaction and promote the electron transfer from the M-NbO2 counter electrode (CE) to I, and thus resulting in superior catalytic properties in M-NbO2 based DSSCs. In addition, the adsorption energy of I on the M-NbO2 surface is in the optimal energy range of 0.3?1.2 eV, and the Fermi level of M-NbO2 is 0.6 eV, which is higher than the I3? reduction reaction (IRR) potential and I3? can be spontaneously reduced to 3I?. This work provides a general strategy for understanding the electronic structures and catalytic activities of transition metal compounds as CE catalysts for DSSCs.
关键词： electrocatalytic activity,counter electrodes,first-principles DFT calculations,dye-sensitized solar cells,niobium oxides
更新于2025-09-11 14:15:04