Elevating the Photothermal Conversion Efficiency of Phase-Change Materials Simultaneously toward Solar Energy Storage, Self-Healing, and Recyclability
Shiwei Zhao, Anqian Yuan, Hualiang Xu, Zhengkai Wei, Shiyi Zhou, Yao Xiao, Liang Jiang, Jingxin Lei
Abstract
To alleviate the predicament of resource shortage and environmental pollution, efficiently using abundant solar energy is a great challenge. Herein, we prepared unique photothermal conversion phase-change materials, namely, CNT@PCMs, by introducing carbon nanotubes (CNTs) used as photothermal conversion materials into the recyclable matrix of phase-change materials (PCMs). These devised CNT@PCMs cleverly combine the photothermal conversion capability of CNTs and the thermal energy storage capability of traditional PCMs. Especially, the surface temperature of the prepared CNT@PCMs can be raised to 100 °C within 165 s under the solar simulator (150 mW cm–2), showing a surprising heating rate that is much higher than that of the reported works and achieving a higher photothermal conversion efficiency for solar energy in this work. Furthermore, these CNT@PCMs can hold high melting latent heat with a maximum value at 110.0 J g–1, exhibiting remarkable thermal storage ability aside from preeminent photothermal conversion capability. Intriguingly, the introduction of dynamic oxime group–carbamate bonds into the molecular structure can endow CNT@PCMs with an outstanding self-healing performance and recyclability. The broken CNT@PCMs sample can be healed in 2 min under IR-laser irradiation. Importantly, the phase-change and mechanical properties and photothermal conversion efficiency of CNT@PCMs can also remain virtually unchanged after multiple recycles. It is of great significance to design this style of CNT@PCMs for achieving the efficient utilization of solar energy and environmental protection.