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Chain-spherical V 2 O 5 /C composites were prepared by using dandelion fibers as bio-templates through a simple vacuum-assisted immersion method, and their microstructure and electromagnetic wave (EMW) absorption properties were investigated. Results indicated that the EMW absorption performance of dandelion fibers is effectively improved by introducing V 2 O 5 and constructing chain-spherical structure. Notably, the minimum reflection loss (RL min) of V 2 O 5 /C composites with a thickness of 2.35 mm is reached −34.05 dB at 17.52 GHz, and the maximum effective absorption bandwidth (EAB) of the composites is up to 7.52 GHz at 2.85 mm. The improvement in EMW absorption performance is mainly ascribed to the synergistic effects of the increased multiple reflections and scattering, enhanced polarization loss and conduction loss, and impedance matching characteristics. The chain-spherical V 2 O 5 /C composites exhibit great potential as promising candidates for high-performance EMW absorbers. • The V 2 O 5 /C composites with a chain-spherical structure are facilely prepared. • The synergy effect of multiple loss mechanisms enhances microwave absorption. • The RL min of −34.05 dB and the widest EAB of 7.52 GHz are achieved. [ABSTRACT FROM AUTHOR]

Magnetic composites had attracted considerable attention owing to their outstanding properties in separation techniques. In this work, Fe 3 O 4 @polydopamine-g- l -cysteine (Fe 3 O 4 @PDA-g-L-Cys) core-shell composites were successfully fabricated via dopamine self-polymerization and zwitterionic cysteine covalent graft, aiming for removing Pb2+ from an aqueous solution. The structure and morphology of Fe 3 O 4 @PDA-g-L-Cys were verified by FT-IR, XRD, TEM and SEM. The factors (pH, adsorbent dosage, temperature, initial concentration, etc.) affecting the adsorption properties were systematically evaluated. Adsorption data were expressed by the Langmuir isotherm. The kinetic date of Fe 3 O 4 @PDA-g-L-Cysadsorbent for Pb2+adsorptionfitted the pseudo-second order kinetic model well. The obtained thermodynamics constantsΔ G 0, Δ H 0, and Δ S 0 indicated that process of Pb2+ removal by Fe 3 O 4 @PDA-g-L-Cys were endothermic and spontaneous. • A controllable strategy to prepare Fe 3 O 4 @PDA@L-Cys was presented for the first time. • The factors affecting the adsorption properties were systematically evaluated. • Fe 3 O 4 @PDA@L-Cys exhibited high adsorption capacity to Pb2⁺ and excellent recyclability. • The thermodynamic properties of adsorption behavior of Fe 3 O 4 @PDA@L-Cys were studied. [ABSTRACT FROM AUTHOR]