In this work, the hierarchical tin oxide nanoflowers have been successfully synthesized via a simple hydrothermal method followed by calcination. The as-obtained samples were investigated as a kind of gas sensing material candidate for methanol. A series of examinations has been performed to explore the structure, morphology, element composition, and gas sensing performance of as-synthesized product. The hierarchical tin oxide nanoflowers exhibit sensitivity to 100 ppm methanol and the response is 58, which is ascribed to the hierarchical structure. The response and recovery time are 4 s and 8 s, respectively. Moreover, the as-prepared sensor has a low working temperature of 200 °C which is lower than that for other gas sensors of such type has been reported elsewhere. The excellent sensitivity of the sensor is caused by its complex phase mixture of SnO, SnO2, Sn2O3, and Sn6O4 revealed by XRD analysis. The proposed hierarchical tin oxide nanoflowers gas sensing material is promising for development of methanol gas sensor. The as-obtained hierarchical tin oxide nanoflower (HTONF) gas sensor shows excellent gas-sensing performance at low working temperature (200 °C) and high annealing temperature (400 °C).

A facile method was developed to prepare Bi/CN_x nanocomposites for high performance energy storage devices.

Simultaneous study of magnetic and electrocatalytic properties of cobaltites under extreme conditions expands the understanding of physical and chemical processes proceeding in them with the possibility of their further practical application. Therefore, La_0.6Sr_0.4CoO₃ (LSCO) nanopowders were synthesized at different annealing temperatures t_ann = 850-900 °C, and their multifunctional properties were studied comprehensively. As t_ann increases, the rhombohedral perovskite structure of the LSCO becomes more single-phase, whereas the average particle size and dispersion grow. Co³⁺ and Co⁴⁺ are the major components. It has been found that LSCO-900 shows two main Curie temperatures, T_C1 and T_C2, associated with a particle size distribution. As pressure P increases, average ⟨T_C1⟩ and ⟨T_C2⟩ increase from 253 and 175 K under ambient pressure to 268 and 180 K under P = 0.8 GPa, respectively. The increment of ⟨dT_C/dP⟩ for the smaller and bigger particles is sufficiently high and equals 10 and 13 K/GPa, respectively. The magnetocaloric effect in the LSCO-900 nanopowder demonstrates an extremely wide peak δT_fwhm > 50 K that can be used as one of the composite components, expanding its working temperature window. Moreover, all LSCO samples showed excellent electrocatalytic performance for the oxygen evolution reaction (OER) process (overpotentials of only 265-285 mV at a current density of 10 mA cm^-2) with minimal η₁₀ for LSCO-900. Based on the experimental data, it was concluded that the formation of a dense amorphous layer on the surface of the particles ensures high stability as a catalyst (at least 24 h) during electrolysis in 1 M KOH electrolyte.

Core(phosphate)–shell(Ni(OH)₂–NiOOH) nanoparticles as stable OER electrocatalysts with low overpotentials of 250–290 mV were prepared by chemical and electrochemical conversion of phosphate in an alkaline medium.

Doping with metal ions can significantly enhance the electrochemical performance of Na₃V₂(PO₄)₃ (NVP) as a cathode material for sodium-ion batteries (SIBs). Despite its high reversible capacity and high voltage, practical application of NVP is limited by its poor intrinsic conductivity. Herein, we shed light on a facile sol-gel synthesis method to prepare NVP with ternary doping of potassium K⁺, Al³⁺, and SO₄^2- ions, which accelerates the migration of Na⁺ in the crystal structure, as confirmed by theoretical calculations. The new cathode materials exhibit a notable reversible capacity of 115.3 mA·h g^-1 at 0.5C and retain a substantial initial capacity of 79.1 mA·h g^-1 even at 50C. Additionally, we synthesized NVP with the doping of SO₄^2- ion on the PO₄^3- site, which shows 90.6 and 85 mA·h g^-1 at 0.5 and 10C, respectively. These results perfectly demonstrate the advantages of the superiority of ternary substitution on the NVP cathode. Moreover, sodium anode-free full cells of the cathode paired with Cu/SP foil showed impressive long-term cycling stability. This achievement lays a strong foundation for the use of NASICON cathodes with high charge-discharge rates and high energy density, making them a promising alternative to the next-generation lithium-ion batteries.