High density Ti3C2TX-graphene quantum dot-Ru monolithic film electrode with rich anisotropic microstructures for high-performance supercapacitor and piezoresistive pressure sensor

Ti3C2TX become a promising electrode and pressure sensing material because of high conductivity. However, poor anisotropy limit its practical applications in high-performance pressure sensor. This study reports one solution for protonated arginine and serine-functionalized graphene quantum dot (RS-GQD+)-regulated synthesis of Ti3C2TX-Ru monolithic film. Dropped RS-GQD + aqueous solution to Ti3C2TX aqueous solution to initiate the self-assembly of Ti3C2TX sheets. Followed by reaction with RuCl3 to produce Ru nanocrystals and subsequent vacuum filtration. Adjusting amounts of RS-GQD + results in formation of monolithic Ti3C2TX-Ru film with ultrahigh density of 3.52 g cm−3 and rich anisotropic microstructures. The structure achieves to excellent supercapacitor and pressure sensing behavior. The soft symmetrical supercapacitor with Ti3C2TX-Ru film electrodes without current collector, conductive agent and binder exhibits ultrahigh specific capacitance of 779.3 F g−1 at 1 A g−1 (1828.7 F cm−3) and energy density of 43.8 W h kg−1 at 225 W kg−1. The Ti3C2TX-Ru film pressure sensor offers high-resolution distinguish subtle and complex pressure changes with superhigh sensitivity and precision. Its piezoresistive current linearly increases with increasing pressure between 0.02 and 30 kPa with detection limit of 0.0067 kPa. The self-powered pressure sensor shows broad application prospect in monitoring human movement, writing and facial expression.