Enhanced electromagnetic wave absorption of three-dimensional flower-like ZnO/TiO2/Ti3C2Tx composites

A novel strategy that selecting Ti3C2Tx MXene as the precursor of TiO2 and the support panel for ZnO crystal growth was reported for the synthesis of ZnO/TiO2/Ti3C2Tx hybrids with serial unique 3D architectures via a facile solvothermal method. The morphology changed from blooming flowers (especially for a regular 3D hexagon blooming rose) to ice-cream ball, macaron, hamburger, and urchin morphologies with an increase in the Ti3C2Tx concentration. The special morphologies were controlled by the direction and the support of ZnO growth that influenced by the functional groups and morphology of Ti3C2Tx. The distinctive in situ formation of multilayered interphases was originated from the morphology of regular 3D flowers with separated 2D nanosheets, and the co-growth of the component simultaneously increased interfacial compatibility. Both of them were beneficial to enhance the electromagnetic wave absorption (EWA) performances. All the series of composites exhibited better EWA properties than TiO2/Ti3C2Tx without the hierarchical structure, manifesting that the synergistic effect of component design and hierarchical architectures played a crucial role in EWA performances. Among the composites, S4 that had a spherical blooming flower morphology exhibited the minimum reflection loss of -31.96 dB at a thickness of 2.5 mm, and the effective frequency bandwidth reached up to 2.24 GHz at a thickness of 5 mm. The reasons for the differences in EWA properties of the series of composites were discussed in detail from aspect of EWA mechanism. This work provides a new idea for the rational design of high-performance absorbers.