Surface-Active and Templated Biocarbon Derived from Pluronic F-127 and Heteroatom-Doped Sucrose and its WO3 Composites with Enhanced Pseudocapacitance for Uranium Electrosorption

The current study involves the preparation of surface-active and templated biocarbon from Pluronic F-127 doped sucrose (DSC) through furnace-based pyrolysis at 550oC while its tungsten oxide-based composites (DSC/WO3) were prepared via hydrothermal reactions. These novel DSC/WO3 materials were tested for their potential applications in competitive uranium recovery through capacitive deionization. To improve the hydrophilicity, chelation, and pseudocapacitance of DSC, definite concentrations of phytic acid and chitosan were incorporated to surround the core part of DSC/WO3. Later, these core-shell-based DSC/WO3 composites were electrodeposited with different mole fractions of polypyrrole (0.0, 0.1, 0.2 and 0.3M) to improve the specific capacitance (Csp), EDL thickness, and electrode conductivity through extended conjugation of the π-electronic cloud. The CV, PSP, and GCD studies concluded the supercapacitor-type behavior of DSC/WO3 with improved cyclic stability without undergoing Faradic processes at various current densities. The prepared composites were characterized through SEM-EDS, FTIR, XRD, and BET to elucidate their structural properties. The DSC/WO3-2 exhibited an appreciable surface area (32.5 m2/g), pore volume (0.26 cm3/g), and average pore size (26.41nm). The DSC/WO3-3 composite (electrodeposited with 0.3M PPy) exhibited better Csp (133.84F/g) but lower sorption capacity (245.93mg/g) than DSC/WO3-2 (298.09mg/g) at optimized voltage (-1.2V) and pH (4.5). This evidenced that excessive electrodeposition of PPy not only decreased the active surface area but also blocked the DSC mesopores and retarded the UO22+ diffusivity. The experimental data depicts that the DSC/WO3-2 composite could be an excellent supercapacitor electrode material for uranium removal.