Porous carbonized cotton loaded with Zn-Cu-M(M=O, S) nanocomposites for electrochemical energy storage and oxygen evolution reaction

A new strategy has been designed for enhancing the electrochemical performances of the supercapacitor and water-splitting electrodes. Hetero-structure composite electrode based on copper sulfide (CuS), zinc oxide (ZnO), and porous carbonized cotton (PCc) is prepared via vacuum thermal evaporation technology and successive ionic layer adsorption methods. Porous substrate provides plenty of active sites, which facilitates the exchange of ions/charges in the electrode processes. The composite electrode exhibits outstanding electrochemical energy storage and electrocatalytic performances. The symmetrical super-capacitor as assembled reaches a high energy density of 0.27 Wh cm(-2) at the power density of 3.34 W cm(-2). By optimizing the composite structure, the energy barriers of the CuS/ZnO/PCc compound are reduced obviously in oxygen evolution reaction in comparison with pure PCc or CuS/PCc. The overpotential of the sample is decreased to 337 mV (10 mA cm(-2) of the loop current) compared to that of PCc (492 mV) and CuS/PCc (415 mV). This work may inspire the rational design of composite electrode materials to achieve high performance in cross-field applications. (C) 2021 Elsevier Ltd. All rights reserved.

Automated summary

A new strategy has been designed to enhance the electrochemical performance of supercapacitors and water-splitting electrodes by preparing a composite electrode based on CuS, ZnO, and PCc. The composite electrode exhibits outstanding electrochemical energy storage and electrocatalytic performances, achieving high energy density and reduced energy barriers in the oxygen evolution reaction compared to pure materials. This work may inspire the rational design of composite electrode materials for high performance in cross-field applications.