Energy storage is a global critical issue and important area of research as most of the renewable sources of energy are intermittent. In this research work, recently emerged inorganic nanomaterial (MXene) is used for the first time with paraffin wax as a phase change material (PCM) to improve its thermo-physical properties. This paper focuses on preparation, characterization, thermal properties and thermal stability of new class of nanocomposites induced with MXene nanoparticles in three different concentrations. Acquired absorbance (UV-Vis) for nanocomposite with loading concentration of 0.3 wt.% of MXene achieved ~39% enhancement in comparison with the pure paraffin wax. Thermal conductivity measurement for nanocomposites in a solid state is performed using a KD2 PRO decagon. The specific heat capacity (c p ) of PCM based MXene is improved by introducing MXene. The improvement of c p is found to be 43% with 0.3 wt.% of MXene loaded in PCM. The highest thermal conductivity increment is found to be 16% at 0.3 wt.% concentration of MXene in PCM. Decomposition temperature of this new class of nanocomposite with 0.3 wt.% mass fraction is increased by ~6%. This improvement is beneficial in thermal energy storage and heat transfer applications.

In this work, we apply an amine-assisted silica pillaring method to create the first example of a porous Mo2TiC2 MXene with nanoengineered interlayer distances. The pillared Mo2TiC2 has a surface...

<p>In this work, we apply an amine-assisted silica pillaring method to create the first example of a porous Mo₂TiC₂MXene with nanoengineered interlayer distances. The pillared Mo₂TiC₂ has a surface area of 202 m² g^-1, which is among the highest reported for any MXene, and has a variable gallery height between 0.7 and 3 nm. The expanded interlayer distance leads to significantly enhanced cycling performance for Li-ion storage, with superior capacities, rate capabilities and cycling stabilities in comparison to the non-pillared version. The pillared Mo₂TiC₂ achieved capacities over 1.7 times greater than multilayered MXene at 20 mA g^-1 (≈ 320 mAh g^-1) and 2.5 times higher at 1 A g^-1 (≈ 150 mAh g^-1). The fast-charging properties of pillared Mo₂TiC₂ are further demonstrated by outstanding stability even at 1 A g^-1 (under 8 min charge time), retaining 80% of the initial capacity after 500 cycles. Furthermore, we use a combination of spectroscopic techniques (i.e. XPS, NMR and Raman) to show unambiguously that the charge storage mechanism of this MXene occurs by a conversion reaction through the formation of Li₂O. This reaction increases by 2-fold the capacity beyond intercalation, and therefore, its understanding is crucial for further development of this family of compounds. In addition, we also investigate for the first time the sodium storage properties of the pillared and non-pillared Mo₂TiC₂.</p>

<p></p><p>In this work, we apply an amine-assisted silica pillaring method to create the first example of a porous Mo₂TiC₂MXene with nanoengineered interlayer distances. The pillared Mo₂TiC₂ has a surface area of 202 m² g^-1, which is among the highest reported for any MXene, and has a variable gallery height between 0.7 and 3 nm. The expanded interlayer distance leads to significantly enhanced cycling performance for Li-ion storage, with superior capacities, rate capabilities and cycling stabilities in comparison to the non-pillared version. The pillared Mo₂TiC₂ achieved capacities over 1.7 times greater than multilayered MXene at 20 mA g^-1 (≈ 320 mAh g^-1) and 2.5 times higher at 1 A g^-1 (≈ 150 mAh g^-1). The fast-charging properties of pillared Mo₂TiC₂ are further demonstrated by outstanding stability even at 1 A g^-1 (under 8 min charge time), retaining 80% of the initial capacity after 500 cycles. Furthermore, we use a combination of spectroscopic techniques (i.e. XPS, NMR and Raman) to show unambiguously that the charge storage mechanism of this MXene occurs by a conversion reaction through the formation of Li₂O. This reaction increases by 2-fold the capacity beyond intercalation, and therefore, its understanding is crucial for further development of this family of materials. In addition, we also investigate for the first time the sodium storage properties of the pillared and non-pillared Mo₂TiC₂.</p><br><p></p>

<p>In this work, we apply an amine-assisted silica pillaring method to create the first example of a porous Mo₂TiC₂MXene with nanoengineered interlayer distances. The pillared Mo₂TiC₂ has a surface area of 202 m² g^-1, which is among the highest reported for any MXene, and has a variable gallery height between 0.7 and 3 nm. The expanded interlayer distance leads to significantly enhanced cycling performance for Li-ion storage, with superior capacities, rate capabilities and cycling stabilities in comparison to the non-pillared version. The pillared Mo₂TiC₂ achieved capacities over 1.7 times greater than multilayered MXene at 20 mA g^-1 (≈ 320 mAh g^-1) and 2.5 times higher at 1 A g^-1 (≈ 150 mAh g^-1). The fast-charging properties of pillared Mo₂TiC₂ are further demonstrated by outstanding stability even at 1 A g^-1 (under 8 min charge time), retaining 80% of the initial capacity after 500 cycles. Furthermore, we use a combination of spectroscopic techniques (i.e. XPS, NMR and Raman) to show unambiguously that the charge storage mechanism of this MXene occurs by a conversion reaction through the formation of Li₂O. This reaction increases by 2-fold the capacity beyond intercalation, and therefore, its understanding is crucial for further development of this family of compounds. In addition, we also investigate for the first time the sodium storage properties of the pillared and non-pillared Mo₂TiC₂.</p>