The development of high-performance glucose sensors is of great significance for blood glucose monitoring and diabetes management. In this work, we designed and synthesized a novel nanocomposite electrocatalyst featuring hierarchical yolk–shell structured CuO/Co₃O₄@Co₃O₄ hybridized with graphitic carbon nitride (g-C₃N₄). The electrocatalytic performance for glucose oxidation was significantly enhanced by optimizing the mass ratio of the CuO/Co₃O₄@Co₃O₄ yolk–shell nanocubes to g-C₃N₄. The optimized composite electrode (with a 5:1 mass ratio) demonstrated exceptional sensing with an ultra-fast response (2 s) and recovery (4 s), outstanding reproducibility and excellent anti-interference capability. When engineered into a screen-printed electrode platform, this sensor achieved a sensitivity of 0.12 μA/(μM·cm²) with a wide linear detection range from 0.001 to 2.0 mM. Density functional theory (DFT) calculations reveal that the combination of CuO and Co₃O₄ can break the charge symmetry on Co atoms, enhance the material’s activity, as well as stronger adsorption for glucose, accelerating the accumulation of target molecules on the sensor surface during detection. Furthermore, a portable sensing device was successful developed by integrating this fabricated sensor with a miniaturized potentiostat. The superior electrocatalytic activity of CuO/Co₃O₄@Co₃O₄/g-C₃N₄ nanocomposite establishes a highly promising candidate for non-enzymatic glucose sensing technologies.

The development of piezoelectric ceramics characterized by both large piezoelectric response and high-temperature stability is imperative for the advancement of practical electromechanical devices. However, existing high-performance piezoelectric ceramics often encounter compromised temperature stability because ferroelectric phase transitions occur within low-temperature regions. In this work, we focused on Sm-doped Pb(Ni_1/3Nb_2/3)O₃–PbZrO₃–PbTiO₃ (PNN–PZT:Sm) ceramics with a tetragonal (T)-phase structure to achieve the desired combination of high piezoelectricity and high temperature stability. The results indicate that 2 mol% Sm-doped samples exhibit a large piezoelectric constant (d₃₃) of 575 pC/N, an effective piezoelectric strain coefficient (d₃₃^*) of 890 pm/V, and a high ferroelectric-to-paraelectric phase transition temperature (T_m) of 279 °C. Remarkably, d₃₃ experiences only a 2.6% variation over the temperature range of 30–250 °C, while d₃₃^* changes by 8% within the temperature range of 30–180 °C. Microstructural and domain structure analyses suggest that Sm-doping effectively reduces the grain size, leading to a decreased domain size, thereby achieving excellent electromechanical properties. The superior temperature stability is attributed to the suppressive effect of Sm-doping on the R–T ferroelectric phase transition. These studies suggest that Sm-doping represents an effective strategy for achieving the collaborative optimization of piezoelectricity and temperature stability through grain and domain engineering techniques for perovskite ferroelectric materials.