Lead-free antiferroelectric materials hold promise as alternatives to lead-containing dielectrics, but the challenge of irreversible room-temperature phase transitions in sodium niobate (NaNbO₃) has hindered their application. This work innovatively employs a tin (Sn) and cerium (Ce) co-doping strategy, successfully achieving precise control over the phase structure of NaNbO₃. The study found that the sample with x=0.04 exhibits reversible electric-field-induced ferroelectric/antiferroelectric (AFE ⇄ FE) phase transitions at room temperature, displaying the characteristic double hysteresis loops and a positive strain of 0.38%. The team also clarified the key mechanism involving Sn²⁺/Ce³⁺ occupying A-sites and Sn⁴⁺/Ce⁴⁺ occupying B-sites through atmosphere-controlled sintering. This work paves a new avenue for the design and application of high-performance lead-free antiferroelectric materials.

Dopamine plays a crucial role in regulating various brain functions, making the development of highly sensitive detection methods and precise quantitative analysis. techniques of great significance. However, realizing highly selective and sensitive detection of dopamine in complex biological environments remains a challenge. Here, we prepared 3D crumpled Ti₃C₂T_x structures loaded with Pt nanoparticles (Pt/Na- Ti₃C₂T_x) by wet chemical reduction and ion intercalation. The synergistic coupling between Pt nanoparticles and MXene support facilitates efficient electron transfer between dopamine and the electrode surface, thereby improving the sensing performance of dopamine. Furthermore, this wrinkled structure not only enhances the specific surface area by inhibiting the stacking of layered Ti₃C₂T_x nanosheets, but also effectively prevents the agglomeration of nanoparticles. The experimental results showed that Pt/Na- Ti₃C₂T_x possessed a wide linear range (0.1-100 μM), a low detection limit (0.029 μM), and a high sensitivity (0.556 μAμM^-1cm^-2). This work proposes an innovative strategy for achieving highly sensitive dopamine detection while advancing the utilization of MXene-based nanocomposites in electrochemical sensor development.

Micro-supercapacitors (MSCs) face significant limitations due to low energy density despite their high power density and long cycle life. In this study, single-layer Ti₃C₂T_x nanosheets are employed to fabricate a MXene-hydroxylated nanocellulose-carbon nanotube (MHC) composite ink, which is used to fabricate high-energy flexible MSCs via direct ink writing 3D printing technology. The introduction of the rheological modifier hydroxylated nanocellulose (HNC) not only constructs interlayer spacers to inhibit nanosheet restacking but also optimizes the rheological properties and 3D printability of the composite ink. Meanwhile, the synergistic effect of carbon nanotubes (CNTs) as conductive agents enhances interlayer electron transport and electrochemical performance. Benefiting from the rational design of the ink and printing process, the fabricated MSCs exhibit high-precision structures (electrode width of 250 μm, electrode area of 0.2625 cm²) and outstanding energy storage properties, achieving 543 mF cm^-2 areal capacitance, 27.15 μWh cm^-2 energy density, and 6 mW cm^-2 power density, significantly surpassing previously reported MXene-based MSCs. Moreover, the flexible all-solid-state MSCs demonstrate excellent performance stability under mechanical bending, series/parallel module integration, and long-term cycling tests, providing a customizable energy storage solution for flexible wearable microelectronic systems.

A new study has introduced a machine learning-based approach to improve the reliability of Global Navigation Satellite System (GNSS) ambiguity resolution, a critical step for achieving high-precision positioning.