Sandwich-like nanostructure of amorphous ZnSnO 3 encapsulated in carbon nanosheets for enhanced lithium storage

Comprehensive review of micro/nanostructured ZnSnO3: characteristics, synthesis, and diverse applications

Generally, zinc stannate (ZnSnO3) is a fascinating ternary oxide compound, which has attracted significant attention in the field of materials science due to its unique properties such high sensitivity, large specific area, non-toxic nature, and good compatibility. Furthermore, in terms of both its structure and properties, it is the most appealing category of nanoparticles. The chemical stability of ZnSnO3 under normal conditions contributes to its applicability in various fields. To date, its potential as a luminescent and photovoltaic material and application in supercapacitors, batteries, solar cells, biosensors, gas sensors, and catalysts have been extensively studied. Additionally, the efficient energy storage capacity of ZnSnO3 makes it a promising candidate for the development of energy storage systems. This review focuses on the notable progress in the structural features of ZnSnO3 nanocomposites, including the synthetic processes employed for the fabrication of various ZnSnO3 nanocomposites, their intrinsic characteristics, and their present-day uses. Specifically, we highlight the recent progress in ZnSnO3-based nanomaterials, composites, and doped materials for their utilization in Li-ion batteries, photocatalysis, gas sensors, and energy storage and conversion devices. The further exploration and understanding of the properties of ZnSnO3 will undoubtedly lead to its broader implementation and contribute to the advancement of next-generation materials and devices.

Enhanced electrochemical performances based on ZnSnO3 microcubes functionalized in-doped carbon nanofibers as free-standing anode materials

The binary composite, ZnSnO3 microcubes (ZSO MC) homogeneously parceled in an N-doped carbon nanofiber membrane (ZSO@CNFM), was synthesized via a mild hydrothermal, electrospinning and carbonization process as a flexible lithium-ion battery (LIB) anode material. The unique carbon-coating layer architecture of ZSO@CNFM not only plays a crucial role in alleviating the volume change of ZSO MC during lithium ion insertion/extraction processes, but also constructs a three-dimensional (3D) transport network with the help of interconnected carbon nanofibers (CNFs) to ensure the structural integrity of the material and promote the electrochemical reaction kinetics. Due to its good flexibility characteristics, the as-prepared ZSO@CNFM can be directly adopted as an anode material for LIBs without the use of copper foil, conductive carbon black and any binder. Electrochemical surveying results manifest that the optimal ZSO@CNFM electrode displays excellent cycling stability (582.6 mA h g-1 after 100 lithiation/delithiation cycles at 100 mA g-1), high coulombic efficiency (CE, 99.6% at 100th cycles), and superior rate performance (349.5 mA h g-1 at 2 A g-1). The good electrochemical properties can be ascribed to the synergistic effect of the high theoretical specific capacity of ZSO MC, favourable stability of the carbon substrate, the open structure of ZSO@CNFM and the 3D continuous highly conductive framework for rapid electron/ion transfer.

Formation of unique hollow ZnSnO3@ZnIn2S4 core-shell heterojunction to boost visible-light-driven photocatalytic water splitting for hydrogen production

Herein, it is reported that a batch of hollow core-shell heterostructure photocatalysts were carefully fabricated using a reliable and convenient low-temperature solvothermal method, and ultra-thin ZnIn₂S₄ nanosheets are grown in situ on the hollow ZnSnO₃ cubes to achieve efficient photocatalytic hydrogen evolution. This unique layered hollow structure utilizes multiple light scattering/reflection within the cavity to enhance light absorption, the thin shell reduces the path of charge transfer, and the irregular nanosheets-wrapped outer layer not only enhances the adsorption power, but also provides an abundant active sites to promote the efficiency of photocatalytic water splitting to produce hydrogen. Therefore, due to the matching energy band and unique structure, the ZnSnO₃@ZnIn₂S₄ hollow core-shell heterostructure photocatalyst exhibits superior H₂ production efficiency (16340.18 μmol h^-1 g^-1) and outstanding stability. This work emphasizes the importance of carefully designing a suitable material structure in addition to adjusting the chemical composition.

Silver Doped Zinc Stannate (Ag-ZnSnO3) for the Photocatalytic Degradation of Caffeine under UV Irradiation

Contaminants of emerging concerns (CECs) spread across a wide range of organic product compounds. As biorecalcitrants, their removal from conventional wastewater treatment systems remains a herculean task. To address this issue, heterogenous solar driven advanced oxidation process based-TiO2 and other semiconductor materials has been extensively studied for their abatement from wastewater sources. In this study, we have synthesized by hydrothermal assisted co-precipitation Ag doped ZnSnO3. Structural and morphological characterizations were performed via X-ray diffraction (XRD), Fourier transform infra-red (FTIR), N2 adsorption-desorption at 77 K by Brunauer-Emmet-Teller (BET) and Barrett, Joyner, and Halenda (BJH) methods, Transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), Scanning electron microscopy coupled with Energy dispersive spectroscopy (SEM-EDS), and UV-visible absorption in Diffuse reflectance spectroscopy (UV-vis/DRS) mode. Crystallite size estimate for Ag-ZnSnO3 and undoped form was 19.4 and 29.3 nm, respectively, while respective TEM particle size estimate was 79.0 nm and 98.2 nm. BET surface area and total pore volume by BJH for Ag-ZnSnO3 were estimated with respective values of 17.2 m2/g and 0.05 cm3/g in comparison to 18.8 m2/g and 0.06 cm3/g for ZnSnO3. Derived energy band gap (Eg) values were 3.8 eV for Ag-ZnSnO3 and 4.2 eV for ZnSnO3. Photocatalytic performance of Ag-ZnSnO3 was tested towards caffeine achieving about 68% removal under (natural) unmodified pH = 6.50 and almost 100% removal at initial pH around 7.5 after 4 h irradiation. The effect of initial pH, catalyst dosage, pollutant concentration, charge scavengers, H2O2, contaminant inorganic ions (anions) as well as humic acid (HA) on the photocatalyst activity over caffeine degradation were assessed. In accordance with the probation test of the reactive species responsible for photocatalytic degradation process, a reaction mechanism was deduced.

A SnOx Quantum Dots Embedded Carbon Nanocage Network with Ultrahigh Li Storage Capacity

Tin-based materials with high specific capacity have been studied as high-performance anodes for energy storage devices. Herein, a SnO_x (x = 0, 1, 2) quantum dots@carbon hybrid is designed and prepared by a binary oxide-induced surface-targeted coating of ZIF-8 followed by pyrolysis approach, in which SnO_x quantum dots (under 5 nm) are dispersed uniformly throughout the nitrogen-containing carbon nanocage. Each nanocage is cross-linked to form a highly conductive framework. The resulting SnO_x@C hybrid exhibits a large BET surface area of 598 m² g^-1, high electrical conductivity, and excellent ion diffusion rate. When applied to LIBs, the SnO_x@C reveals an ultrahigh reversible capacity of 1824 mAh g^-1 at a current density of 0.2 A g^-1, and superior capacities of 1408 and 850 mAh g^-1 even at high rates of 2 and 5 A g^-1, respectively. The full cell assembled using LiFePO₄ as cathode exhibits the high energy density and power density of 335 Wh kg^-1 and 575 W kg^-1 at 1 C based on the total active mass of cathode and anode. Combined with in situ XRD analysis, the superior electrochemical performance can be attributed to the SnO_x-ZnO-C asynchronous and united lithium storage mechanism, which is formed by the well-designed multifeatured construction composed of SnO_x quantum dots, interconnected carbon network, and uniformly dispersed ZnO nanoparticles. Importantly, this designed synthesis can be extended for the fabrication of other electrode materials by simply changing the binary oxide precursor to obtain the desired active component or modulating the type of MOFs coating to achieve high-performance LIBs.

Electrostatic-Interaction-Driven Assembly of Binary Hybrids towards Fire-Safe Epoxy Resin Nanocomposites

Manganese dioxide (MnO₂), as a promising green material, has recently attracted considerable attention of researchers from various fields. In this work, a facile method was introduced to prepare binary hybrids by fabricating three-dimensional (3D) zinc hydroxystannate (ZHS) cubes on two-dimensional (2D) MnO₂ nanosheets towards excellent flame retardancy and toxic effluent elimination of epoxy (EP) resin. Microstructural analysis confirmed that the morphologies and structures of MnO₂@ZHS binary hybrids were well characterized, implying the successful synthesis. Additionally, the morphological characterization indicated that MnO₂@ZHS binary hybrids could achieve satisfactory interfacial interaction with the EP matrix and be well dispersed in nanocomposites. Cone calorimeter test suggested that MnO₂@ZHS binary hybrids effectively suppressed the peak of heat release rate and total heat release of EP nanocomposites, performing better than MnO₂ or ZHS alone. Condensed-phase analysis revealed that MnO₂@ZHS binary hybrids could promote the char density and graphitization degree of char residues and thereby successfully retard the permeation of oxygen and flammable gases. Moreover, through the analysis of gas phase, it can be concluded that MnO₂@ZHS binary hybrids could efficiently suppress the production of toxic gases during the degradation of EP nanocomposites. This work implies that the construction of 2D/3D binary hybrids with an interfacial interaction is an effective way to fabricate high-performance flame retardants for EP.

Embedding ultrafine ZnSnO3 nanoparticles into reduced graphene oxide composites as high-performance electrodes for lithium ion batteries

Ultrafine ZnSnO₃ nanoparticles, with an average diameter of 45 nm, homogeneously grown on reduced graphene oxide (rGO) have been successfully fabricated via methods of low temperature coprecipitation, colloid electrostatic self-assembly, and hydrothermal treatment. The uniformly distributed ZnSnO₃ nanocrystals could inhibit the restacking of rGO sheets. In turn, the existence of rGO could hinder the growth and aggregation of ZnSnO₃ nanoparticles in the synthesis process, increase the conductivity of the composite, and buffer the volume expansion of the ZnSnO₃ nanocrystals upon lithium ion insertion and extraction. The obtained ZnSnO₃/rGO exhibited superior cycling stability with a discharge/charge capacity of 718/696 mA h g^-1 after 100 cycles at a current density of 0.1 A g^-1.

Ion exchange for synthesis of porous CuxO/SnO2/ZnSnO3 microboxes as a high-performance lithium-ion battery anode

Integrating other oxides and ZnSnO₃ with porous structures can accommodate volume expansion and enhance the electrochemical performance.