MXene@LDH基相变材料用于光热存储和微波吸收

Abstract: 2D MXene is highly preferred for photothermal energy conversion and microwave absorption. However, the aggregation issue, insufficient dielectric loss capacity and lack of magnetic loss capacity for MXene severely hinder its practical applications. Herein, we propose multi-dimensional nanostructure engineering to electrostatically assemble 2D MXene and layered double hydroxides (LDH) derived from ZIF-67 polyhedron into 3D hollow framework (LDH@MXene), and subsequently calcined to construct a Co nanoparticle-modified 3D hollow C-LDH@MXene framework to encapsulate a paraffin wax (PW) phase change material (PCM). The 3D hollow C-LDH@MXene framework not only prevents 2D MXene from aggregation, but also contributes a high thermal energy storage density (131.04 J/g). Benefiting from 3D conductive network facilitating the rapid transport of photons and phonons from the interface to the interior and the synergistic localized surface plasmon resonance (LSPR) effect of MXene and Co magnetic nanoparticles, the C-LDH@MXene-PW composite PCM yielded a high photothermal storage efficiency of 96.52%. Besides, C-LDH@MXene-PW composite PCMs also exhibited efficient microwave absorption with a minimum reflection loss of -20.87 dB at 13.30 GHz with the matching thickness of only 2 mm. This distinctive design provides constructive references for the development of integrated composite materials for energy storage and microwave absorption.

Figure 1 Preparation schematic of composite materials

Figure 2 (a) SEM, (b) TEM and (c) High-resolution TEM of LDH. (d) SEM, (e) TEM and (f) EDS mapping of LDH@MXene. (g) SEM and (h) TEM of C-LDH. (i) SEM and (j-k) of C-LDH@MXene.

Figure 3 (a) SEM images of (a) LDH-PW, (b) LDH@MXene-PW, (c) C-LDH-PW, (d) C-LDH@MXene-PW. (e-f) DSC curves of composite PCMs. (g) Latent heat retention and DSC cycling curves of C-LDH@MXene-PW with 50 heating/cooling cycles. (h) Heat transfer enhancement mechanism of C-LDH@MXene.

Figure 4 (a) Photothermal conversion curves under 0.10 W/cm2. (b) Photothermal storage efficiencies. (c) Schematic illustration of photothermal energy conversion mechanism for C-LDH@MXene-PW. (d) Dynamic digital photos of C-LDH@MXene-PW under near-infrared laser irradiation. (e) IR thermal images of thermoregulating textile under solar irradiation.

Figure 5 RL curves of (a) LDH-PW, (b) LDH@MXene-PW, (e) C-LDH-PW, (f) C-LDH@MXene-PW. Three-dimensional diagrams of RL values for (c) LDH-PW, (d) LDH@MXene-PW, (g) C-LDH-PW, (h) C-LDH@MXene-PW. (i) Schematic illustration of microwave absorption mechanism for C-LDH@MXene.

文献链接：Yan Gao1, Jinjie Lin1, Xiao Chen*, Zhaodi Tang, Geng Qin, Ge Wang*. Engineering 2D MXene and LDH into 3D hollow framework for boosting photothermal energy storage and microwave absorption. Small, 2023, 2303113.

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