Nanoengineering of MgSO4 nanohybrid on MXene substrate for efficient thermochemical heat storage material

2D MXene nanohybrid is a next-generation energy-storage material. Here, we demonstrate a novel thermo-chemical heat storage material using magnesium sulfate heptahydrate/titanium carbide and MXene (MgSO4/ Ti3C2Tx) with improved hydration/dehydration enthalpy, superior thermal conductivity, good cyclic ability, maximum water sorption performance, and larger thermal energy conversion. The TG-DSC fitted with a Wetsys flow humidity generator shows outstanding thermal performance and larger hydration for MgSO4/Ti3C2Tx (1963 J/g) and dehydration (1861 J/g) enthalpies with 5 % fluctuation as compared to pure MgSO4 (38 %). The cyclicability results showed that MgSO4/MXene has good stability of TCMs across several charging/discharging cycles (up to 20 cycles), confirming that the MXene matrix avoids hydrated salt agglomeration and displays an average of 12 % fluctuation. This illustrates that prepared composites potentially improve storage performance. The MgSO4/Ti3C2Tx nanohybrid exhibit a better radiation absorption and 45 % longer backup than the pristine MgSO4 salt. TEM study revealed that maximum salt contents can be located in the interlayer gaps, predicted sheets thickness of the MgSO4/MXene layer to be 16 A and the Ti3C2Tx layers to be 7.3 A. Nanohybrid has stronger water sorption than MgSO4 due to MXene nanosheets larger interlayer gaps. The results conclude that the resultant MgSO4/MXene has excellent long-term thermal energy storage, photo-to-thermal conversion and larger water sorption performance. The study validates the effectiveness of nanohybrid material as a promising candidate for thermochemical heat storage applications and set to pave the way to explore other hybrid systems to improve the efficiency of thermochemical energy storage systems.