High-performance dye-sensitized solar cells using Ag-doped CoS counter electrodes

Bisphenol A cleanup over MIL-100(Fe)/CoS composites: Pivotal role of Fe-S bond in regenerating Fe2+ ions for boosted degradation performance

Series of MIL-100(Fe)/CoS composites (MxCy) were facilely fabricated using ball-milling method. The optimum M50C50 exhibited extremely higher Fenton-like catalytic degradation activity toward bisphenol A (BPA) than the pristine MIL-100(Fe) and CoS. The significant improvement of BPA degradation was attributed to the synergetic effect between MIL-100(Fe) and CoS with the synergistic factor being 95.7%, in which the Fe-S bonds formed at the interface of the two components facilitate the Fe³⁺/Fe²⁺ cycle by improving the electron mobility both from Co to Fe and from S to Fe. Furthermore, the influence factors like co-existing inorganic ions and pH values on the catalysis activity of M50C50 were explored. The possible reaction mechanism was proposed and confirmed by both active species capture tests and electron spin resonance (ESR) determinations. It was found that M50C50 demonstrated good reusability and water stability, in which the morphology and structure were not changed obviously after five runs' operation. To our best knowledge, it is the first work concerning the interfacial interaction of Fe-MOF/MSx to promote Fe³⁺/Fe²⁺ cycle in Fe-MOFs for the purpose of organic pollutants degradation in the Fenton-like AOPs system.

Facile construction of a polypyrrole–cobalt sulfide counter electrode for low-cost dye-sensitized solar cells

A polypyrrole–cobalt sulfide composite counter electrode (CE) was prepared in this work. Firstly, polypyrrole (PPy) nanorods were prepared by an in situ polymerization method on FTO, then cobalt sulfide (CoS) nanoparticles were coated on PPy nanorods by the electrodeposition method. The DSSC with PPy–CoS CE exhibits superior photoelectric conversion efficiency than that based on platinum (Pt, one of common counter electrodes), which is 7.52%, improving more than 20% compared to Pt CE (6.19%). In addition, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) measurements demonstrated that the PPy–CoS CE exhibited excellent catalytic performance for I₃⁻/I⁻ solution.

A facile two-step strategy to construct a polypyrrole–cobalt sulfide counter electrode for low-cost dye-sensitized solar cells.

Quantum dot embedded N-doped functionalized multiwall carbon nanotubes boost the short-circuit current of Ru(ii) based dye-sensitized solar cells

Here, we report zinc sulfide quantum dots, ZnS(QDs), moored on N-doped functionalized multiwall carbon nanotubes (MWCNTs) wrapped with reduced graphene oxide (rGO). The MWCNTs have a tangled network, a particular surface area, and a distinctive hollow structure that may be suitable for use as a counter electrode (CE) material. A ZnS@N.f-MWCNTs@rGO composite as the CE on a fluorine-doped tin oxide substrate in a dye-sensitized solar cell (DSSC) was fabricated using a doctor blade technique. The electrochemical performance showed that at the electrolyte/CE interface, the ZnS(QDs) and N-doped functionalized MWCNTs wrapped with rGO (ZnS@N.f-MWCNTs@rGO) electrode has a lower transfer charge resistance (R_ct) and a greater catalytic capacity than naked ZnS(QDs). A power conversion efficiency (PCE) of 9.4% was attained for this DSSC gadget, which is higher than that of a DSSC gadget utilizing ZnS(QDs), ZnS@N.f-MWCNTs, ZnS@rGO and Pt. Also, the DSSC device using ZnS@N.f-MWCNTs@rGO had a fill factor (FF) that was better than the other counter electrodes. The cyclic voltammetry and electrochemical impedance spectra (EIS) electron transfer measurements showed that ZnS@N.f-MWCNTs@rGO films can provide fast electron transfer from the electrolyte to the CE and great electrocatalytic activity to reduce triiodide to a CE based on ZnS@N.f-MWCNTs@rGO in the DSSC.