- 标题
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- 实验方案
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Synthesis of a MoS <i> <sub/>x</sub></i> -O-PtO <i> <sub/>x</sub></i> Electrocatalyst with High Hydrogen Evolution Activity Using a Sacrificial Counter-Electrode
摘要： Water splitting is considered to be a very promising alternative to greenly produce hydrogen, and the key to optimizing this process is the development of suitable electrocatalysts. Here, a sacrificial-counter-electrode method to synthesize a MoSx/carbon nanotubes/Pt catalyst (0.55 wt% Pt loading) is developed, which exhibits a low overpotential of 25 mV at a current density of 10 mA cm?2, a low Tafel slope of 27 mV dec?1, and excellent stability under acidic conditions. The theory calculations and experimental results confirm the high hydrogen evolution activity that is likely due to the fact that the S atoms in MoSx can be substituted with O atoms during a potential cycling process when using Pt as a counter-electrode, where the O atoms act as bridges between the catalytic PtOx particles and the MoSx support to generate a MoSx–O–PtOx structure, allowing the Pt atoms to donate more electrons thus facilitating the hydrogen evolution reaction process.
关键词： sacrificial-counter-electrodes,O substitution,MoSx,hydrogen evolution reaction,PtOx
更新于2025-09-23 15:23:52
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Theoretical and experimental insights into the effects of oxygen-containing species within CNTs towards triiodide reduction
摘要： Heteroatom-doped micro/nano-structured carbon materials feature unique superiorities for replacement of noble metal Pt counter electrode (CE) in dye-sensitized solar cells. Nevertheless, the effects of oxygen-containing species on/within carbon matrix on its electrocatalytic activity are seldomly considered and concerned, which will be hindered by a trade off between oxygen defects and conductivity. Herein, we present activated carbon nanotubes (P-CNTs) with abundant active edge sites and oxygen species for simultaneous achieving the activation of sidewalls and open ends. Also, the positive effects of oxygen species are decoupled by experimental data together with theoretical analysis. When capitalizing on the P-CNTs as the CE of DSSCs, the device delivers a high power conversion efficiency of 8.35% and an outstanding electrochemical stability, outperforming that of Pt reference (8.04%). The density functional theory calculation reveals that compared with the carboxylic groups, the hydroxyl groups and carbonyl groups on the surface of CNTs can greatly reduce the ionization energy of reaction, accelerate the electron transfer from external circuit to triiodide, thus being responsible for an enhanced electrocatalytic performance. This work demonstrates that a certain amount of oxygen atoms within carbon materials is also indispensable for the improvement in the reactivity of the triiodide.
关键词： Counter electrodes,Triiodide reduction,Defective carbon nanotubes,Ionization energy,Electrochemical stability,Oxygen species
更新于2025-09-23 15:23:52
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Several economical and eco-friendly bio-carbon electrodes for highly efficient perovskite solar cells
摘要： One of the major problems limits the applications of perovskite solar cells (PSCs) is the high cost of hole transporting materials (HTMs) and noble metallic electrodes. For HTMs and noble-metal-free PSCs, carbon materials have been utilized as counter electrodes (CEs). In this paper, four kinds of ultra-low-cost bio-carbon materials have been applied and compared in PSCs. Results showed that the photovoltaic performance of PSCs based on different bio-carbon CEs was determined by the interfacial connection, work function (WF), sheet resistance, crystallinity, and morphology of these bio-carbons. The high PCE (12.82%) of PSCs based on bio-carbon CEs has been achieved in current state-of-the-art. PSCs based on bio-carbon CEs was more stable than that of conventional devices, which could retain 87% of their initial PCE after storing for 2000 hours in room temperature. Our work proposes a new pathway for the exploration of low-cost bio-carbon materials and could accelerate the applications of PSCs based on carbon electrode.
关键词： stability,perovskite solar cells,counter electrodes,photovoltaic performance,bio-carbon
更新于2025-09-23 15:19:57
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Construction of Pt-free electrocatalysts based on hierarchical CoS2/N-doped C@Co-WS2 yolk-shell nano-polyhedrons for dye-sensitized solar cells
摘要： Nanomaterials with yolk-shell structures are identified as promising advanced catalysts in energy conversion devices due to their larger surface area, more efficient active sites, and shorter charge transfer paths. In this work, we developed a facile template method to synthesize yolk-shell structured CoS2/N-doped C@Co-WS2 (CoS2/NC@Co-WS2) as counter electrode material in dye-sensitized solar cells. In detail, zeolitic imidazolate framework-67 (ZIF-67) as a template reacted with (NH4)2WS4 through an anion conversion/exchange processes, which was followed by the subsequent sulfuration reaction. Additionally, the influence of mass ratio between reactions on the morphologies and electrochemical properties of catalysts were further explored. When the mass ratio of the ZIF-67 precursors and (NH4)2WS4 is 5/1, CoS2/NC@Co-WS2 delivered a superior power conversion efficiency of 9.21% for Pt-free dye-sensitized solar cells which was much higher than that of Pt (8.18%). This result could be attributed to the coordination of multiple elements, prominent yolk-shell structure, and the largest surface area (110 m2 g?1).
关键词： Nano-polyhedrons,CoS2/NC@Co-WS2,Counter electrodes,Catalytic activities,Dye-sensitized solar cells
更新于2025-09-23 15:19:57
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Tellurium-Doped, Mesoporous Carbon Nanomaterials as Transparent Metal-Free Counter Electrodes for High-Performance Bifacial Dye-Sensitized Solar Cells
摘要： Tellurium-doped, mesoporous carbon nanomaterials with a relatively high doping level were prepared by a simple stabilization and carbonization method in the presence of a tellurium metalloid. A transparent counter electrode (CE) was prepared using tellurium-doped, mesoporous carbon (TeMC) materials, and was directly applied to bifacial, dye-sensitized solar cells (DSSCs). To improve the performance of the bifacial DSSC device, CEs should have outstanding electrocatalytic activity, electrical conductivity, and electrochemical stability, as well as high transparency. In this study, to make transparent electrodes with outstanding electrocatalytic activity and electrical conductivity, various TeMC materials with di?erent carbonization temperatures were prepared by simple pyrolysis of the polyacrylonitrile-block-poly (n-butyl acrylate) (PAN-b-PBA) block copolymer in the presence of the tellurium metalloid. The electrocatalytic activity of the prepared TeMC materials were evaluated through a dummy cell test, and the material with the best catalytic ability was selected and optimized for application in bifacial DSSC devices by controlling the ?lm thickness of the CE. As a result, the bifacial DSSC devices with the TeMC CE exhibited high power conversion e?ciencies (PCE), i.e., 9.43% and 8.06% under front and rear side irradiation, respectively, which are the highest values reported for bifacial DSSCs to date. Based on these results, newly-developed transparent, carbon-based electrodes may lead to more stable and e?ective bifacial DSSC development without sacri?cing the photovoltaic performance of the DSSC device.
关键词： transparency,bifacial devices,mesoporous carbon,tellurium-doped,counter electrodes,dye-sensitized solar cells
更新于2025-09-16 10:30:52
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Recent progress in quantum dot-sensitized solar cells employing metal chalcogenides
摘要： As one of the most promising third-generation photovoltaics devices, quantum dot-sensitized solar cells (QDSCs) have attracted increasing attention due to their easy fabrication, low cost, potential high efficiency, etc. Thus, substantial efforts have been taken to boost their photoelectrical conversion efficiencies (PCEs) and device stability consistently by precisely optimizing the structure of materials and device architecture. Throughout the development of QDSCs, it is noteworthy to mention that metal chalcogenide-based semiconductors have been key materials in capturing sunlight as sensitizers, catalytic electrolyte reduction as counter electrodes (CEs), and interface charge transport as interface modification layers. Herein, we systematically review the recent progress on metal chalcogenide-based QDSCs in practical applications from three main functional points, specifically, QD sensitizers, counter electrodes (CEs), and interface modification layers. Besides, we have outlined the fundamental structure, operation principle, and brief history of these sensitized solar cells. Finally, the state of existing challenges and future prospects for QDSCs employing various metal chalcogenides are also discussed.
关键词： interface modification layers,photoelectrical conversion efficiencies,sensitizers,counter electrodes,quantum dot-sensitized solar cells,metal chalcogenides
更新于2025-09-16 10:30:52
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Platinum counter electrodes for dye-sensitized solar cells prepared by one-step dipping process
摘要： When designing counter electrodes (CEs) to enhance the performance of dye-sensitized solar cells (DSSCs), facile routes are important features. Platinum (Pt) metal is one of the most-promising CE designs for DSSCs. Herein, we developed a simple, and cost-effective one-step dipping process for preparing Pt CEs in DSSCs. The Pt CEs were prepared by dipping fluorine-doped tin oxide (FTO) in a 3-mercaptopropyl triethoxysilane (MTS)-Pt suspension. We tested and compared MTS-1-Pt, MTS-10-Pt, and sputtered-Pt as CEs in DSSCs. MTS-1-Pt and MTS-10-Pt refer to samples prepared with 1 and 10 ml of MTS, respectively. DSSCs with MTS-1-Pt CEs exhibited power conversion efficiency (PCE) values as high as 8.28%, which was superior to the DSSCs using MTS-10-Pt as the CEs (1.61%). Additionally, the DSSCs with MTS-1-Pt CE showed mostly similar PCEs compared to those with sputtered-Pt (8.55%) because of the same catalytic activity with iodide. Thus, this modified Pt CE facile process can be used to further enhance the performance of DSSCs.
关键词： one-step dipping process,catalytic activity,power conversion efficiency,Platinum counter electrodes,dye-sensitized solar cells
更新于2025-09-16 10:30:52
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Synthesis of MOF-derived bimetallic nanocarbons CuNi@C with potential applications as counter electrodes in solar cells
摘要： A Cu–Ni-containing bimetallic carbon-based material was prepared by the pyrolysis of a metal-organic framework (MOF) synthesized from copper and nickel salts and trimesic acid precursors at room temperature. This material was tested as a counter electrode for the reduction of I3– by means of cyclic voltammetry.
关键词： MOF-derived bimetallic nanocarbons,counter electrodes,CuNi@C,solar cells
更新于2025-09-16 10:30:52
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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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In situ electrodeposition of nickel cobalt selenides?on FTO as an efficient counter electrode for dye-sensitized solar cells
摘要： Construction of transition metal selenides with high electrocatalytic performance is of significant importance, but it is still a challenge to develop the corresponding counter electrodes (CEs) by an electrodeposition technique. In the present work, nickel cobalt selenide (NixCoySe) films are prepared in situ on fluorine-doped tin oxide (FTO) glasses through a potential reversal electrodeposition technique. The morphology and electronic structure of NixCoySe films can be tuned by controlling the Ni/Co molar ratio in electroplating solution. Specially, NixCoySe-6 film (the Ni/Co molar ratio of 1:1) with the optimized interaction between the Ni and Co elements displays numerous particles composed of sheets attached with nanocrystals, resulting in the more electrocatalytic active sites. Benefiting from the unique morphology and optimized synergistic effect, NixCoySe-6 CE exhibits superior electrocatalytic activity for the triiodide reduction. Then, the dye-sensitized solar cell (DSC) fabricated by NixCoySe-6 CE has demonstrated a power conversion efficiency (PCE) over 7.40%, which is higher than that of platinum (Pt)-based device (6.32%). Furthermore, NixCoySe-6 array CE is also prepared by using polystyrene array as template. The PCE of the DSC with NixCoySe-6 array CE reaches its maximum value of 7.64% and 20.9% larger than that of Pt-based device.
关键词： Potential reversal electrodeposition technique,Synergistic effect,Nickel cobalt selenides,Counter electrodes,Array
更新于2025-09-16 10:30:52