Recent Advances in Counter Electrodes for Thiolate-mediated Dye-sensitized Solar Cells

Dye-sensitized solar cells (DSSCs) based on disulfide/thiolate (T₂/T⁻) redox couples have attracted remarkable attention due to their high efficiency and low cost. As an indispensible part of DSSCs, counter electrode (CE) design plays a crucial role in high efficiency DSSCs. This mini-review paper selectively reviews the recent advances in T-mediated DSSCs using novel CE (namely cathode) materials, mainly including noble metal platinum (Pt), carbon materials, transition metal compounds (TMCs), polymers, and hybrids, thus highlighting the merits and demerits of alternative Pt catalysts, and the prospects and challenges of Pt-free CEs for the development of high-performance and low-cost DSSCs.     

Optical,electrochemical, and photovoltaic properties of conjugated polymers with dithiafulvalene as side chains

Three conjugated polymers, P1–P3, with dithiafulvalene (DTF) as side chains have been synthesized. All polymers have good thermal stabilities. The DTF unit could be oxidized to DTF?⁺ which was observed from cyclic voltammetry and ultraviolet–visible (UV–vis) spectra, and the oxidation process was independent of the conjugated backbone of the polymer. The strong π–π* transition absorbing band of the three polymers decreases gradually as increasing oxidation, and the resulting DTF?⁺ species give rise to an additional band at 750–1100 nm, which can be assigned to a distinguishing feature of the cation radical species. Photovoltaic device based on the blend of P2 and [6,6]‐phenyl‐C61‐butyric acid methyl ester (PC₆₁BM) showed the power conversion efficiency of 1.05% with a fill factor of 42.8%. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41508.     

Fullerene-like Re-Doped MoS2 Nanoparticles as an Intercalation Host with Fast Kinetics for Sodium Ion Batteries

Sodium ion batteries (SIBs) are considered as a promising alternative to threaten the reign of lithium ion batteries (LIBs) among various next-generation rechargeable energy storage systems, including magnesium ion, metal air, and metal sulfur batteries. Since both sodium and lithium are located in Group 1 of the periodic table, they share similar (electro)chemical properties with regard to ionization pattern, electronegativity, and electronic configuration; thus the vast number of compounds developed from LIBs can provide guidance to design electrode materials for SIBs. However, the larger ionic radius of the sodium cation and unique (de)sodiation processes may also lead to uncertainties in terms of thermodynamic or kinetic properties. Herein, we present the first construction of SIBs based on inorganic fullerene-like (IF) MoS₂ nanoparticles. Closed-shell-type structures, represented by C₆₀ fullerene, have largely been neglected for studies of alkali-metal hosting materials due to their inaccessibility for intercalating ions into the inner spaces. However, IF-MoS₂, with faceted surfaces, can diffuse sodium ions through the defective channels, thereby allowing reversible sodium ion intercalation/deintercalation. Interestingly, Re-doped MoS₂ showed good electrochemical performances with fast kinetics (ca. 74 mA h g⁻¹ at 20 C). N-type doping caused by Re substitution of Mo in IF-MoS₂ revealed enhanced electrical conductivity and an increased number of diffusion defect sites. Thus, chemical modification of fullerene-like structures through doping is proven to be a promising synthetic strategy to prepare improved electrodes.     

Laccase‐catalyzed synthesis of polypyrrole‐multiwalled carbon nanotube composites as energy storage materials for capacitors

Multiwalled carbon nanotubes (MWNTs) were coated with polypyrrole (PPy) using in situ enzymatic polymerization of pyrrole catalyzed by a laccase (benzenediol:oxygen oxidoreductase, EC 1.10.3.2) from Trametes versicolor. Transmission electron microscopy revealed that the MWNTs were uniformly coated with very thin layers of PPy without any indication of globular polymer aggregate formations. The enzymatic synthesis of the MWNTs/PPy composites was quite simple being performed in a one‐pot aqueous solution (pH 4.0) under mild reaction conditions. The potential of the composites with respect to the development of energy storage devices was demonstrated by fabricating a two‐electrode coin cell capacitor (diameter 20 mm, thickness 1.6 mm) utilizing the composites as electrode materials. The capacitance of the cell was 28.0 F g^?1 for the electrode material as measured by a galvanostatic charge–discharge method. The energy density and power density were 2.55 and 805 W kg^?1, respectively, which were close to those of the capacitors classified as ultracapacitors. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43307.     

Structure,thermal stability,electrochemical behaviors,and mechanical properties of organosoluble polyimide with pyrimidine ring in the main chain

A novel organosoluble polyimide (PI) with pyrimidine ring in the main chain was synthesized by chemical and thermal imidization, respectively, from 3,3′,4,4′‐benzophenone tetracarboxylic dianhydride and 2,4‐diamino‐6‐chloropyrimidine as raw materials and its molecular structure, solubility, UV–visible absorption characteristic, crystallinity, thermal stability, electrochemical behaviors, and mechanical properties were also studied. It was found that the introduction of pyrimidine ring in the main chain could increase the solubility of PI in polar aprotic solvents at room temperature and 60 °C, respectively, because of its molecular main chain with asymmetric structure and two polar N atoms in pyrimidine ring. Furthermore, PI had strong optical absorption peak intensity, excellent thermal stability, good redox reversibility, especially outstanding mechanical properties, which were conductive to its potential applications in adhesives, polyelectrolyte, separation membrane, and so on. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43680.     

Quaternized poly(phenylene oxide) anion exchange membrane for alkaline direct methanol fuel cells in KOH‐free media

A series of anion exchange membrane (AEM) electrolytes with quaternary ammonium moiety are fabricated from poly (phenylene oxide) for its application in alkaline direct methanol fuel cells (ADMFCs). In the first step, poly(phenylene oxide) (PPO) is successfully chloromethylated by substituting chloromethyl groups in the aryl position of polymer. In the second step, the chloromethylated PPO (CPPO) is further homogeneously quaternized and ion‐exchanged to form an AEM. From the second step, series of AEMs are prepared by changing the mole ratio of amine in relation to CPPO. The presence of quaternary ammonium group in the membrane was confirmed by elemental analysis. The fabricated membranes are subjected to cell polarization studies in ADMFCs, wherein quaternized poly(2,6‐dimethyl‐1,4‐phenylene oxide) (CPPO:amine of 1:8) membrane exhibits higher peak power density of 3.5 mW cm^?2 when compared with the other ratios of CPPO:amine in the absence of KOH solution. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43693.     

Facile fabrication of superhydrophobic polyaniline structures and their anticorrosive properties

We report a simple approach for the preparation of superhydrophobic polyaniline (PANI) and its application for the corrosion protection coatings. First, PANI was synthesized conventionally by oxidative polymerization with APS. Subsequently, PANI with different wettability was obtained by modification with different surfactants. The surface modification of PANI with three different surfactants (sodium dodecylbenzenesulfonate, polyethylene glycol, and cetyltrimethylammonium bromide) provided excellent surface superhydrophobicity (water contact angle >150°). The structure and morphology of as‐prepared PANI were characterized with Fourier transform infrared, Energy dispersive X‐ray spectroscopy, and Scanning electron microscopy. Corrosion protection performance of PANI with different wettability was evaluated in 3.5% NaCl electrolyte using Tafel polarization curves and electrochemical impedance spectroscopy. The results indicated that various superhydrophobic PANI coatings have better anticorrosion performance as compared to the hydrophilic PANI. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 44248.     

Polythiophene nanoparticles in aqueous media

The article presents the data concerning the synthesis of polythiophene (PTh) nanoparticles in aqueous medium applying emulsion polymerization. The synthetic method was studied in variety of combinations of initiator and surfactant. It was found that application of potassium peroxydisulfate (KPS) as initiator and sodium dodecyl sulfate (SDS) as the surfactant gives the best product yields. The structure, morphology, and physicochemical properties have been analyzed showing that the resulting latex have conducting film forming properties. Resulting polymers were characterized via fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM), thermogravimetry‐differential thermal analysis (TG‐DTA), differential scanning calorimetry (DSC), and electrochemical methods [e.g. current–voltage characteristics (I–V), activation energy of electric conductivity, and doping processes]. A mechanism of the polymerization reaction is also discussed. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43495.