Although the inorganic salt hydrate phase change materials (PCMs) such as CaCl2 center dot 6H(2)O have promising potential for thermal energy storage in building application, the issue of supercooling has restricted their practical application. In this study, graphene oxide (GO) and SrCl2 center dot 6H(2)O as binary nucleation agents were used to modify CaCl2 center dot 6H(2)O and reduce its supercooling degree. Compared with pure CaCl2 center dot 6H(2)O, the incorporation of graphene oxide (GO)/SrCl2 center dot 6H(2)O reduced the supercooling degree to 0.3 degrees C significantly. In addition, the supercooling degree of modified CaCl2 center dot 6H(2)O after 200 thermal cycles was still much lower than that of non-modified CaCl2 center dot 6H(2)O. From the results of differential scanning calorimetry (DSC), the latent heat value and phase change temperature of the modified CaCl2 center dot 6H(2)O were 207.88 J/g and 27.6 degrees C, respectively. Aluminum capsules were used to encapsulate the modified PCM and placed inside the composite wallboard. The thermal performances of the composite wallboard with modified PCM were investigated using infrared thermography. Experimental results showed that the average temperature difference between the top and bottom surfaces of modified CaCl2 center dot 6H(2)O/wallboard composite after 1 h heating was kept around 15.8 degrees C, while it was 4.9 degrees C for the control wallboard. The above test results proved that the modified CaCl2 center dot 6H(2)O demonstrated good thermal performance and can be used in buildings to maintain thermal comfort.