A novel 2D mesoporous phosphazene-anthraquinone-based covalent organic polymer: synthesis, characterization and supercapacitor applications

Covalent organic polymers (COPs) are designable porous organic polymers that have attracted increasing research interest and have developed as electrode materials for supercapacitors. By using an easy synthesis method, a novel phosphazene-anthraquinone-based covalent organic polymer (HD-1) was successfully designed and synthesized through a polymerization reaction between hexachlorocyclotriphosphazene (HCCP) and 2,6-diaminoanthraquinone (DAAQ) in dimethylsulphoxide (DMSO). Fourier transform infrared (FT-IR) spectroscopy, X-ray photoelectron spectroscopy (XPS), nitrogen adsorption-desorption analysis, powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), energy dispersive X-ray spectrometr (EDX) and thermogravimetric analysis (TGA) were used to characterize the structure and properties of HD-1. The specific surface was calculated as 249.2 m²g⁻¹. The specific capacitance of HD-1 was 125.6 F g⁻¹at a current density of 0.5 A g⁻¹in a 6.0 M potassium hydroxide electrolyte. After 20 000 GCD cycles, the specific capacitance retention was about 92.8% of its initial capacitance.