Phase Change Thermal Energy Storage Enabled by an In Situ Formed Porous TiO₂

Uneven and insufficient encapsulation caused by surface tension between supporting and phase change materials (PCMs) can be theoretically avoided if the encapsulation process co-occurs with the formation of supporting materials in the same environment. Herein, for the first time, a one-pot one-step (OPOS) protocol is developed for synthesizing TiO₂ -supported PCM composite, in which porous TiO₂ is formed in situ in the solvent of melted PCMs and directly produces the desired thermal energy storage materials with the completion of the reaction. The preparation features straightforward operation and high environmental metrics with no emission, requires only stirring and heating without the addition of organic solvent or catalyst. Moreover, the preparation process can be easily scaled-up at the laboratory. Because of the OPOS protocol and porous TiO₂ inside, the as-obtained PCM composite possesses a 66.5% encapsulation ratio and 166.8% thermal conductivity enhancement compared to pristine unsupported PCMs, with 94.7% light-to-thermal conversion efficiency and promising bacterial inhibition activity without any leakage.