- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
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
-
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
-
Biomass-derived carbon boosted catalytic properties of tungsten-based nanohybrids for accelerating the triiodide reduction in dye-sensitized solar cells
摘要： Manganese tungstate (MWO), zinc tungstate (ZWO), and copper tungstate (CWO) embedded biomass-derived carbon (MWO-C, ZWO-C, CWO-C) was synthesized by hydrothermal treatment and investigated as counter electrode (CE) catalyst to test electrochemical activity. Biomass-derived carbon was used as the shape controlling agent, which changed the morphology of MWO from spherical to spindle-like. Owing to the synergistic effect between tungsten-based bimetal oxides and biomass-derived carbon, the MWO-C, ZWO-C, and CWO-C catalysts exhibited enhanced electrochemical performance in dye-sensitized solar cells (DSSCs) system. The MWO-C, ZWO-C and CWO-C catalysts in DSSCs showed outstanding power conversion efficiency (PCE) of 7.33%, 7.61%, and 6.52%, respectively, as compared with 7.04% for Pt based devices. Biomass-derived carbon improves the catalytic properties of tungsten-based nanohybrids. The results showed that biomass-derived carbon-enhanced inorganic compound as CE catalysts are promising alternatives to Pt-based CE catalysts for energy conversion devices.
关键词： Triiodide reduction reaction,Counter electrode catalyst,Biomass-derived carbon,Tungsten-based nanohybrids,Dye-sensitized solar cells
更新于2025-09-23 15:21:01
-
Dye-sensitized solar cell-thermoelectric hybrid generator utilizing bipolar conduction in a unified element
摘要： The dye-sensitized solar cell-thermoelectric hybrid generator (DS-TEG), which is a hybridization of a dye-sensitized solar cell (DSSC) and a thermoelectric generator (TEG) not at the structural level but in terms of material-level unification, is presented. The Pt-coated TE element provides electrons to the iodide/triiodide electrolyte to lower the redox barrier. This promotes the reduction of triiodide, resulting in a dramatic increase in the electron recombination lifetime. The available charge density, carrier diffusion coefficient and effective diffusion length were significantly increased when utilizing both types of carriers and acceleration in an iodide/triiodide reduction reaction in the unified DS-TEG.
关键词： Dye-sensitized solar cell,synergetic effect,dye-sensitized thermoelectric hybrid generator,thermoelectric element,triiodide reduction rate
更新于2025-09-23 15:21:01
-
WN/nitrogen-doped reduced graphite oxide hybrids for triiodide reduction in dye-sensitized solar cells
摘要： The development of low-cost, environmental friendliness, outstanding catalytic activity, superior conductivity and good stability counter electrode (CE) catalyst in dye-sensitized solar cells (DSSCs) is important to promote the commercial application of DSSCs. Here, WN/nitrogen-doped reduced graphite oxide hybrids (WN/NrGO) had been synthesized by hydrothermal method followed by nitridation treatment, which used as CE catalysts for catalyzing I3? to I?. The combined WN and nitrogen-doped reduced graphite oxide (NrGO) into WN/NrGO could effectively regulate the catalytic activity for the reduction of I3?, accelerate the charge transfer at the interface, and then the synergistic effect between of them can be fully achieved. When the WN/NrGO served as the CE catalyst in DSSCs, the photoelectric conversion efficiency (PCE) of 7.42% has been obtained, compared to the conventional Pt-based DSSCs (7.71%). Meanwhile, as-prepared WN/NrGO exhibited higher PCE than that of the solo WN (6.19%) and NrGO (5.81%) in parallel. A series of electrochemical measures revealed that the WN/NrGO displayed the higher catalytic activity and charge transfer ability than that of the solo WN and NrGO, so the synthesized low-cost WN/NrGO have an potential to be used as the effectively CE catalysts for the replacement of the noble Pt.
关键词： Dye-sensitized solar cells,Triiodide reduction,Counter electrode,WN/nitrogen-doped reduced graphite oxide
更新于2025-09-12 10:27:22
-
Controlled synthesis of porous nanosheets-assembled peony-like cobalt nickel selenides for triiodide reduction in dye-sensitized solar cells
摘要： Developing counter electrode (CE) materials with outstanding catalytic performance and low cost is a critical step for the large-scale application of dye-sensitized solar cells (DSSCs). In this work, a facile bottom-up solvothermal route followed by a selenization process was introduced to synthesize the hierarchical cobalt nickel selenides nanoflowers (CoeNieSe NFs) consisted of numerous cross-linked porous nanosheets. The structure and composition of CoeNieSe NFs could be regulated by simply tuning the feed molar ratio of Ni/Co. Pro?ting from the well structural nature, relatively large surface area, appropriate porosity, optimized crystal structure and the synergy of multiple components, CoeNieSe NFs display superior catalytic activity toward the triiodide reduction. Impressively, the power conversion ef?ciency (PCE) of DSSC assembled with CoeNieSe-1:1 NFs CE is 9.00%, which outperforms that of Pt CE (7.97%). This strategy sheds a new light on the controlled synthesis of advanced hierarchical materials for the application in the ?eld of sustainable energy.
关键词： Dye-sensitized solar cells,Counter electrode,Cobalt nickel selenides,Triiodide reduction,Peony-like structure
更新于2025-09-11 14:15:04