Tuzluca Yesilbag, Fatma Nur; Yesilbag, Yasar Ozkan; Huseyin, Ahmad; Salih, Ahmed Jalal Salih; Ertugrul, Mehmet

The increasing demand for advanced materials in energy storage underscores the importance of chemical diversity in nanomaterials. Ordered double transition metal (DTM) MXenes have emerged as promising atomically layered 2D materials. This study investigates the flexible Ti2NbC2Tx MXene, synthesized from the ordered Ti2NbAlC2 MAX phase, as a supercapacitor electrode material. Electrochemical analyses revealed specific capacitances of 322 and 642 F g-1 at a current density of 0.5 A g-1 in Na2SO4 (Na) and H2SO4 (H) electrolytes, respectively. Ti2NbC2Tx MXene exhibited exceptional cycling stability, retaining 95% capacitance in Na2SO4 and 100% in H2SO4 after 10,000 charge/discharge cycles. Furthermore, an asymmetric supercapacitor (ASC) was fabricated using Ti2NbC2Tx MXene as the positive electrode and overcapacitive activated carbon as the negative electrode with PVA-Na and PVA-H gel electrolytes. The ASC achieved energy densities of 31.1 and 34.0 W h kg-1 for PVA-Na and PVA-H electrolytes, respectively. These results highlight the potential of Ti2NbC2Tx MXene, with its unique ordered structure and double transition metal composition, for foundational research and applications in advanced energy storage technologies.

Karagoz, Emine; Tuc Altaf, Cigdem; Tuzluca Yesilbag, Fatma Nur; Yesilbag, Yasar Ozkan; Erdem, Emre; Bakan Misirlioglu, Feray; Demirci Sankir, Nurdan; Sankir, Mehmet

In this work, we report a self-powered quasi-solid-state photodetector (PD) device prepared from flexible two-dimensional (2D) nanocomposites of a zinc oxide nanowire (ZnO-NW) in various weight percents (5, 10, 30, 50%) and Ti3C2Tx (MXene) paper, constructed with manganese (Mn)-doped zinc oxide nanorods (ZnO NRs) using an ionic gel electrolyte and carbon paper. All PD performance tests revealed that 5% ZnO-MXene-based devices were superior to the other samples. The maximum detectivity of 1.44 × 1013 Jones at 367 nm (0.1 mW cm-2) and zero bias was calculated for the 5% ZnO-MXene-based device. Additionally, a very high on/off ratio of nearly 106, which is approximately 35-fold higher than that of the 50% ZnO-MXene-based PDs, was achieved for 5% ZnO-MXene PD at a zero bias under 367 nm (2.52 mW cm-2) illumination. The rise time for this device was 9.25 ms. Furthermore, the PD device exhibited excellent stability by enduring 1000 s of light on/off cycles. As a result, a simple, compact, and cost-effective self-powered ZnO-NW:MXene-based PD configuration showed fast photoresponse and excellent detecting performance.