Covalent conductive polymer chain and organic ligand ethylenediamine modified MXene-like-{AlW₁₂O₄₀} compounds for fully symmetric supercapacitors, electrochemical sensors and photocatalysis mechanisms

We successfully synthesized two kinetically stable covalent polymer chains and ethylenediamine modified MXene-like-{AlW₁₂O₄₀} compounds. According to the energy storage research results, these materials showed high capacitance performance and cycle stability. The capacitance values of the 1-CC (carbon cloth) and 2-CC materials are 478.41 and 625.99 F g^-1 (1.0 A g^-1), and the capacitance retention is 95.71% and 97.62% after 5000 cycles, respectively. The symmetric water system supercapacitor device was assembled with two 2-CC and achieved an energy density of 6.32 W h kg^-1 at 237 W kg^-1. Compounds 1 and 2 were used to test the new sensitive current hydrogen peroxide sensor, displaying linear ranges of 1.20-3.20 mM (1-GCE: glassy carbon electrode) and 19.95 μM to 0.90 mM (2-GCE) with a detection limit of 0.93 μM and 0.86 μM, respectively. In addition, the photocatalysis mechanisms of compounds 1 and 2 were studied to provide a powerful basis for the photocatalytic mechanism of this series of compounds.