Nature Materials最新文献

Correction to: Nature Materials https://doi.org/10.1038/s41563-024-01966-1, published online 6 August 2024.

PtM (M = S, Se, Te) dichalcogenides are promising two-dimensional materials for electronics, optoelectronics and gas sensors due to their high air stability, tunable bandgap and high carrier mobility. However, their potential as electrocatalysts for the oxygen reduction reaction (ORR) is often underestimated due to their semiconducting properties and limited surface area from van der Waals stacking. Here we show an approach for synthesizing a highly efficient and stable ORR catalyst by restructuring defective platinum diselenide (DEF-PtSe₂) through electrochemical cycling in an O₂-saturated electrolyte. After 42,000 cycles, DEF-PtSe₂ exhibited 1.3 times higher specific activity and 2.6 times higher mass activity compared with a commercial Pt/C electrocatalyst. Even after 126,000 cycles, it maintained superior ORR performance with minimal decay. Quantum mechanical calculations using hybrid density functional theory reveal that the improved performance is due to the synergistic contributions from Pt nanoparticles and the apical active sites on the DEF-PtSe₂ surface. This work highlights the potential of DEF-PtSe₂ as a durable electrocatalyst for ORR, offering insights into PtM dichalcogenide electrochemistry and the design of advanced catalysts.

Driving synthetic materials out of equilibrium via dissipative mechanisms paves the way towards autonomous, self-sustained robotic motions. However, obtaining agile movement in diverse environments with dynamic steerability remains a challenge. Here we report a light-fuelled soft liquid crystal elastomer torus with self-sustained out-of-equilibrium movement. Under constant light excitation, the torus undergoes spontaneous rotation arising from the formation of zero-elastic-energy modes. By exploiting dynamic friction or drag, the zero-elastic-energy-mode-based locomotion direction can be optically controlled in various dry and fluid environments. We demonstrate the ability of the liquid crystal elastomer torus to laterally and vertically swim in the Stokes regime. The torus navigation can be extended to three-dimensional space with full steerability of the swimming direction. These results demonstrate the possibilities enabled by prestrained topological structures towards robotic functions of out-of-equilibrium soft matter.

The sodium (Na) superionic conductor is a key component that could revolutionize the energy density and safety of conventional Na-ion batteries. However, existing Na superionic conductors are primarily based on a single-anion framework, each presenting inherent advantages and disadvantages. Here we introduce a family of amorphous Na-ion conductors (Na₂O₂–MCl_y, M = Hf, Zr and Ta) based on the dual-anion framework of oxychloride. Benefiting from a dual-anion chemistry and with the resulting distinctive structures, Na₂O₂–MCl_y electrolytes exhibit room-temperature ionic conductivities up to 2.0 mS cm⁻¹, wide electrochemical stability windows and desirable mechanical properties. All-solid-state Na-ion batteries incorporating amorphous Na₂O₂–HfCl₄ electrolyte and a Na_0.85Mn_0.5Ni_0.4Fe_0.1O₂ cathode exhibit a superior rate capability and long-term cycle stability, with 78% capacity retention after 700 cycles under 0.2 C (1C = 120 mA g⁻¹) at room temperature. The discoveries in this work could trigger a new wave of enthusiasm for exploring new superionic conductors beyond those based on a single-anion framework.