Metal Valence State Modulation Strategy to Design Core@shell Hollow Carbon Microspheres@MoSe 2 /MoO x Multicomponent Composites for Anti-Corrosion and Microwave Absorption.

The exploitation of multicomponent composites (MCCs) has become the main pathway for obtaining advanced microwave absorption materials (MAMs). Herein, a metal valence state modulation strategy is proposed to tune the electromagnetic (EM) parameters and improve microwave absorption performances. Core@shell hollow carbon microspheres@MoSe ₂ and hollow carbon microspheres@MoSe ₂ /MoO _x MCCs with various mixed-valence states content are well-designed and produced by a simple hydrothermal reaction or/and heat treatment process. The results reveal that the thermal treatment of hollow carbon microspheres@MoSe ₂ in Ar and Ar/H ₂ leads to the in situ formation of MoO _x and multivalence state, respectively, and the enhanced content of Mo ⁴⁺ in the designed MCCs greatly boosts their impedance matching characteristics, polarization, and conduction loss capacities, which lead to their evidently improved EM wave absorption properties. Amongst, the as-prepared hollow carbon microspheres@MoSe ₂ /MoO _x MCCs achieve an effective absorption bandwidth of 5.80 GHz under a matching thickness of 1.97 mm and minimum reflection loss of -21.49 dB. Therefore, this work offers a simple and universal method to fabricate core@shell hollow carbon microspheres@MoSe ₂ /MoO _x MCCs, and a novel and feasible metal valence state modulation strategy is proposed to develop high-efficiency MAMs.
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