ABSTRACT
Currently, there is a limited amount of research on PEDOT:LS (poly(3,4-ethylenedioxythiophene):sulfonated lignin)-based hydrogels. While the addition of PEDOT:LS can enhance the conductivity of the gel, it unavoidably disrupts the gel network and negatively affects its mechanical properties. The preparation process and freezing resistance of the hydrogels also pose significant challenges for their practical applications. In this study, we have developed a novel self-catalytic system, PEDOT:LS-Fe3+, for the rapid fabrication of conductive hydrogels. These hydrogels are further transformed into eutectogels by immersing them in a deep eutectic solvent. Compared with conventional hydrogels, the eutectogels exhibit improved elongation, mechanical strength, and resistance to freezing. Specifically, the eutectogels containing 2 wt % PEDOT:LS as conductive fillers and catalysts demonstrate exceptional stretchability (â¼460%), self-adhesion (â¼14.6 kPa on paper), UV-blocking capability (â¼99.9%), and ionic conductivity (â¼1.2 mS cm-1) even at extremely low temperatures (-60 °C). Moreover, the eutectogels exhibit high stability and sensitivity in flexible sensing, successfully detecting various human motions. This study presents a novel approach for the rapid preparation of the hydrogels by utilizing lignin in the conductive PEDOT polymerization process and forming a self-catalytic system with metal ions. These advancements make the eutectogels a promising candidate material for flexible wearable electronics.
ABSTRACT
A new material design strategy is developed to prepare high-performance flexible electrochemical electrodes. Carbon nanotubes (CNTs) and nickel/nickelous hydroxide (Ni/Ni(OH)2) are compounded through a chemical plating method and hydrothermal process. A single-side printing method is used to combine the active material and a flexible cotton substrate. The interfinger microstructure of the textile electrode can greatly facilitate charge/ion transfer at the electrode-electrolyte interface. One side of the fabric, which is untreated, could directly contact with human skin, providing a comfortable and user-friendly surface. With the CNTs/Ni/Ni(OH)2 ternary composite as a positive electrode and CNTs as a negative electrode, we assembled an in-plane asymmetrical micro-supercapacitor device (SF-NPCs). Thanks to a synergistic effect, SF-NPCs displays a high energy density of 0.29 W h cm-2 at a power density of 7.2 W cm-2. The operating window is extended to 1.5 V, and the device displays good potential for applications in the field of smart textiles.
ABSTRACT
The composite material composed of zinc sulfide, copper sulfide and porous carbon is prepared in this study, exhibiting excellent performances in the field of supercapacitor electrode and photocatalysts. In the degradation process of organic pollutants, zinc sulfide/copper sulfide with heterostructure effectively reduce the recombination rate of photo-generated electron-hole pairs. And the porous carbon substrate can not only accelerate the separation of photo-carriers but also provide numerous active sites. Furthermore, the sample can be easily separated after decomposing the organic pollutants. As a supercapacitor electrode, the combination of zinc sulfide/copper sulfide with large pseudo-capacitance and porous carbon material with excellent double-layercapacitance results in superior electrochemical performances. The composite electrode shows a high specific capacitance of 1925 mF cm-2/0.53 mAh cm-2 at 4 mA cm-2. And the symmetric flexible supercapacitor based on the composite electrode achieves an outstanding energy density (0.39 Wh cm-2 at the power density of 4.32 W cm-2). Therefore, the zinc sulfide/copper sulfide/porous carbonized cotton nanocomposites (pCZCS) prepared herein exhibit dual functions of photocatalysts with high efficiency as well as energy storage materials with high energy density, which is interesting and important for expanding the practical applications in cross fields.
