Light-heat conversion and thermal conductivity enhancement of PEG/SiO2 composite PCM by in situ Ti4O7 doping

•Novel form-stable composite PCMs have been synthesized.•Composite PCMs have excellent performance of light-thermal conversion.•The phase change enthalpy of composite PCM reached up to 129 J/g.

To improve the energy utilization efficiency of solar energy, Ti4O7/PEG/SiO2 form-stable phase change material (PCM) with characters of light-heat conversion and thermal conductivity enhancement was developed by in-situ doping titanium black (Ti4O7) through acid and alkali catalytic sol-gel method. The structure and properties of PCM were investigated by SEM, FT-IR, XRD, DSC, TG, coefficient of thermal conductivity and thermal conversion testing, etc. The results showed that the Ti4O7/PEG/SiO2 could effectively absorb UV-visible light of solar radiation, simultaneously, the light energy was translated into thermal energy which was storied by PCM. Furthermore, the composite PCM exhibited good thermal stability below 360 °C, excellent shape-stabilized effect and high thermal conductivity. The Ti4O7/PEG/SiO2 as novel thermal storage material can usefully enhance the utilization efficiency of solar energy.

Graphical abstractNovel Ti4O7/PEG/SiO2 composite with UV-visible light-harvesting function was obtained.Download high-res image (262KB)Download full-size image