Highly Efficient Solvothermal Synthesis of Poly(1,5-diaminoanthraquinone) Nanoflowers for Energy and Environmental...

Poly(1,5-diaminoanthraquinone) (PDAA) has attracted more interest because of its unique molecular structure. However, the lower polymerization yield limits its practical application. Here, the solvothermal chemically oxidative polymerization of 1,5-diaminoanthraquinone (DAA) was developed, and the well-defined PDAA nanoflowers were obtained with a high yield of 72.6% within 16 h. The PDAA nanoflower-based flexible film electrodes were fabricated with expandable graphene as conductive support, delivering a capacitance of 277 F g^-1 and 258 mF cm^-2 at 0.5 A g^-1 (1 mA cm^-2) and superior cycling stability with retention of 99% after 10000 cycles. The flexible symmetric solid-state supercapacitors (SSSCs) possessed a high capacitance of 52.5 F g^-1 at 0.25 A g^-1 and 96.6 mF cm^-2 at 1 mA cm^-2 and had only a 14% capacitance loss after 10000 cycles at 0.1 V s^-1 as well as excellent flexibility. Besides, the PDAA nanoflowers could be used as self-separable adsorbent for methylene blue (MB) with a capacity of 93.8 mg g^-1 at pH 9.