Functional groups in two-dimensional (2D) Ti C T MXene are an important factor influencing electrochemical performance in many applications involving energy storage, electrochemical sensors, and water purification. However, after dimethyl sulfoxide (DMSO) delamination, the effect of surface functionalities in Ti C T is still unclear and there are no systematic reports on its capacitive behavior. Experiments and theoretical calculations confirm the relationship between different surface functionalities, the DMSO delamination effect, and the electrochemical behavior of the DMSO-delaminated Ti C T . The dominant -O and -OH terminations are attributed for surfaces delaminated by using HF [Ti C T (HF)] and LiF/HCl [Ti C T (LiF/HCl)], respectively. Theoretical results are also in agreement with experimental results in that -OH terminations are essential for the formation of a free-standing film. Compared to non-delaminated Ti C T (HF) (similar O/F ratios of 1.37 and 1.42), there is a significant DMSO delamination effect for Ti C T (LiF/HCl) because of different O/F ratios of 2.9 and 3.6. Additionally, the delaminated Ti C T (LiF/HCl) electrodes deliver a higher capacitance of 508 F cm than that of 333 F cm for the delaminated Ti C T (HF), although it exhibited lower equivalent series resistance, lower interlayer spacing, and slightly lower specific surface area. This study provides direct and systematic experimental evidence for different functional groups in Ti C T MXene based on the DMSO delamination effect.

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Many studies have focused on histidine behaviors in misfolding diseases. However, histidine behaviors on mature fibrils are still unknown. In the current study, we investigated mature fibrils with various histidine states to understand the structural properties of the histidine tautomeric effect on mature fibrils. Our results show that substituting chain 1 with different histidine states affects Aβ structural properties in A2, D7–G9, H14–Q15, S26–N27, and G33–G37 regions. The binding free energies with substituted fibrils were influenced not only along the axial direction, but also between duplex fibrils. Our results suggest that substituted (εδδ) preferentially disturbed the stability among the current mature fibrils. Further, H-bonded network differences indicate that twisted morphologies in mature fibrils are derived from the position and orientation of the imidazole ring in histidines. Our current study helps to elucidate histidine behaviors on mature fibrils, which will present opportunities to understand the misfolding mechanisms.

Pseudocapacitive asymmetric supercapacitors are promising candidates for achieving high energy density in flexible energy storage devices. However, seeking suitable positive electrode materials that are compatible with negative electrode materials remains a considerable challenge. In the current study, a pseudocapacitive Ti 3 C 2 T x MXene used as negative electrodes is rationally compatible with redox-type V 2 O 5 as positive electrodes, resulting in the assembly of an all-pseudocapacitive Ti 3 C 2 T x MXene//V 2 O 5 asymmetric flexible energy storage device. The solid-state asymmetric device can deliver an energy density of 8.33 mW h cm −3 at a current density of 0.5 A g −1 . Moreover, it can operate in an expanded voltage window of 1.5 V, with dominant surface-capacitive charge-storage mechanisms. Additionally, the device can power a yellow light-emitting diode for up to 7 s, indicating the potential of the device for use in practical applications. This study demonstrates the possibility of using other two-dimensional transition-metal carbide nanosheets for high-energy density flexible energy storage devices.