Nitrogen-Doped Carbon Encapsulated Partial Zinc Stannate Nanocomposite for High-Performance Energy Storage Materials

As a bimetal oxide, partial zinc stannate (ZnSnO3) is one of the most promising next-generation lithium anode materials, which has the advantages of low operating voltage, large theoretical capacity (1,317 mA h g−1), and low cost. However, the shortcomings of large volume expansion and poor electrical conductivity hinder its practical application. The core-shell ZnSnO3@ nitrogen-doped carbon (ZSO@NC) nanocomposite was successfully obtained by coating ZnSnO3 with polypyrrole (PPy) through in situ polymerization under ice-bath conditions. Benefiting from this unique compact structure, the shell formed by PPy cannot only effectively alleviate the volume expansion effect of ZnSnO3 but also enhance the electrical conductivity, thus, greatly improving the lithium storage performance. ZSO@NC can deliver a reversible capacity of 967 mA h g−1 at 0.1 A g−1 after 300 cycles and 365 mA h g−1 at 2 A g−1 after 1,000 cycles. This work may provide a new avenue for the synthesis of bimetal oxide with a core–shell structure for high-performance energy storage materials.

Ficus Carica Mediated Synthesis of Simulated Solar Light Driven Nano-sized Zinc Stannate Photocatalyst for the Degradation of Methylene Blue

The synthesis of zinc stannate nanocomposite (Zn2SnO4 NC) was carried out using an environment friendly process that included the use of Ficus carica (F. carica) leaves extract as a capping and reducing agent. X-ray diffraction (XRD) analysis was used to analyze the structural and crystallographic parameters, and the crystallite was discovered to have cubic geometry. The elemental composition of the studied Zn2SnO4 NC was investigated using energy dispersive X-ray (EDX), which revealed that it was extremely pure. The band gap (3.12 eV) was calculated through Tauc plot using diffuse reflectance (DRS) data where the functional groups were explored through Fourier transform infrared (FTIR) spectroscopy. Prior to the photocatalytic reaction, some preliminary experiments were performed, which proposed that pH 9 is suitable for the mineralization of methylene blue (MB) (10 ppm) in the presence of 20 mg of Zn2SnO4 NC and simulated solar light. The 96 % of MB was degraded in 80 min with the degradation rate of 0.038 min-1.

ANALYSIS OF CHANGES IN THE SURFACE COMPOSITION DURING FORMATION OF ZINC STANNATE NANOSTRUCTURES

Наноструктуры станната цинка были синтезированы гидротермальным методом, в качестве исходных материалов были использованы наностержни оксида цинка. Образование многокомпонентных оксидов было исследовано с помощью рентгеновской фотоэлектронной спектроскопии. Установлено, что в процессе гидротермального синтеза происходит постепенное встраивание ионов олова в кристаллическую решетку наностержней оксида цинка и замещение ионов цинка. с образованием наноструктур станната цинка. Исследование влияния времени синтеза на химический состав поверхности полученных образцов показало, что формирование станната цинка происходит через 1 час, что подтверждается изменением энергий связи цинка и кислорода. При более длительном синтезе происходит разрушение наноструктур станната цинка, оксидов цинка и олова на поверхности образца практически не наблюдается. Zinc stannate nanostructures were synthesized by hydrothermal method, and zinc oxide nanorods were used as starting materials. Formation of multicomponent oxides was studied by using the X-ray photoelectron spectroscopy. It was found that tin ions are gradually embedded in the crystal lattice of zinc oxide nanorods and replaced zinc ions during hydrothermal synthesis with the formation of zinc stannate nanostructures. The study of the synthesis time effect on the surface chemical composition of the prepared samples has shown formation of zinc stannate after 1 hour, that is confirmed by changes in the binding energies of zinc and oxygen. With a longer synthesis, zinc stannate nanostructures collapsed, thus zinc and tin oxides are practically not observed on the sample surface.