One-step preparation and characterization of a nanostructured hybrid electrode material via a microwave energy-based approach

Abstract

A hybrid electrode material (HEM) composed of carbonized conducting polymer (CP), e.g. polypyrrole (PPy), nanofibers (CNFs) decorated with nanostructured zinc oxide (nano-ZnO) and carbon nanotubes (CNTs), was successfully prepared in one-step via a hassle-free, rapid and highly efficient microwave (MW) energy heating-based approach. The morphology, content of the decorative compounds, and thus, overall material properties of the HEM could be simply altered by changing the process parameters, e.g. ratios in the feedstock mixture and the MW process time. The thermal and morphological features, elemental composition, spectroscopic properties, and also electrochemical performance of the as-prepared HEM were thoroughly investigated by using relevant characterization methods such as thermogravimetric analysis (TGA), scanning and transmission electron microscopy (SEM, TEM), energy dispersive X-ray (EDX), X-ray photoelectron (XPS), and Raman spectroscopy, along with cycling voltammetry (CV) and galvanostatic charge/discharge (C–D) tests. It is revealed that by synergistically blending the high conductivity from CNTs, the ultra-high porous specific surface area from CNFs and the abundant pseudo-capacitive feature from nano-ZnO in its structure, the as-prepared HEM could exhibit promising capacitive performance (233.3 F g⁻¹ at 1 A g⁻¹ current density) along with excellent long-term C–D cycling stability (∼90% during 5000 cycles), and competitive energy density (32.41 W h kg⁻¹ at 333.3 W kg⁻¹ power density) values for advanced electrochemical energy storage applications.