Tungsten oxide encapsulated phosphate-rich porous alginate composites for efficient U(VI) capture: Insights into synthesis, adsorption kinetics and thermodynamics.

In this work, novel monoclinic tungsten oxide (WO3)-encapsulated phosphate-rich porous sodium alginate (PASA) microspherical hydrogel beads were prepared for efficient U(VI) capture. These macroporous and hollow beads were systematically characterized through XRD, FTIR, EDX-mapping, and SEM-EDS techniques. The O and P atoms in the PO and monoclinic WO3 offered inner-spherical complexation with U(VI). The in situ growth of WO3 played a significant role inside the phosphate-rich biopolymeric network to improve its chemical stability, specific surface area, adsorption capacity, and sorption rate. The phytic acid (PA) served for heteroatom doping and crosslinking. The encapsulated WO3 mass ratio was optimized in different composites, and WO3/PASA3 (the microspherical beads with a mass ratio of 30.0 % w/w) exhibited remarkable maximum sorption capacity qm (336.42 mg/g) computed through the best-fit Langmuir model (R2 ≈ 0.99) and rapid sorption equilibrium, teq (150 min). The isothermal sorption studies were conducted at different temperatures (298, 303, and 308 K) and thermodynamic parameters concluded that the process of U(VI) sorption using WO3/PASA3 is endothermic and feasible having ΔHo (8.19 kJ/mol), ΔGo (-20.75, -21.38, and - 21.86 kJ/mol) and proceeds with a minute increase in randomness ΔSo (0.09 kJ/mol.K). Tungsten oxide (WO3)-encapsulated phosphate-rich porous microspherical beads could be promising material for uranium removal.

Novel Lignin-Cellulose-Based Carbon Nanofibers as High-Performance Supercapacitors.

In this work, a simple phosphating process was proposed to modify cellulose-acetate (CA) and lignin for a novel energy storage precursor material. The prepared precursor fibers exhibited good thermal stability of lignin and flexibility of CA. Subsequently, the precursor fibers undergo a short preoxidation and carbonization treatment process to obtain the biomass-based carbon fibers (CFs) with complete fibrous morphology, uniform fiber diameter, high surface areas, good flexibility, and excellent power storage capacity. The specific capacitance of 346.6 F/g was obtained by using CFs-5 (prepared with 40% H3PO4 content) as a supercapacitor. Simultaneously, the biomass-based CF supercapacitor device delivers a high-energy density of 31.5 Wh/kg at the power density of 400 W/kg. These results indicate that the introduction of H3PO4 can effectively reduce the energy consumption of the preoxidation treatment process for the preparation of the biomass-based CFs, while increasing the energy storage properties significantly. This novel strategy showed a successful route for the preparation of high-quality and low-consumption biomass-based CFs.