Synthesis of zinc sulfide/copper sulfide/porous carbonized cotton nanocomposites for flexible supercapacitor and recyclable photocatalysis with high performance

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.