Premna-derived heteroatom-doped carbon composites decorated with WO3 nanoparticles for high supercapacitive performance

WO3@PAC composites are prepared by using biomass premna as precursor, with complexation-peeling-carbonization as activation method to induce WO3 nanoparticles growth between 2D premna-based carbon layers (PAC). During the synthesis process, the boric acid can not only regulate the thickness of carbon frame as an activator, but also incorporate B and O elements as a doping agent. With the increase of boric acid dosage, the layered structure gradually thins. Moreover, the 2D premna-based carbon sheets can make WO3 nanoparticles uniformly dispersed, which reduces the volumetric change caused by stacking and agglomeration, and effectively improves the structural stability. Resultantly, the WO3@PAC-3 composites present favorable charge storage properties, showing an ideal specific capacitance of 528.3 F g−1 at 0.5 A g−1. The assembled symmetric supercapacitor displays an optimum energy density of 31.0 Wh·kg−1 and the maximum power density of 7.05 kW kg−1. When applied for capacitive deionization electrodes, WO3@PAC-3 affords good ion adsorption performance with ion adsorption capacity up to 31.2 mg g−1 at 1.2 V, and a rapid brackish water desalination rate of 3.7 mg g−1 min−1. [Display omitted] •Using one-step method to combine biomass polysaccharide (premna) and WO3.•WO3 uniformly dispersed between 2D premna-based carbon nanosheets.•Exploring the effect of 2D sheets with B/N/O content on electrochemical properties.