SnO2 Hollow Research Articles

Sonocatalytic degradation of tetracycline hydrochloride using SnO2 hollow-nanofiber decorated with UiO-66-NH2

In this study, a porous hollow nanofiber SnO2 was decorated with UiO-66-NH2 nanoparticles with straightforward solvothermal method and utilized for sonocatalytic degradation of tetracycline (TC) by ultrasonic irradiation (USI). The prepared materials were characterized using different techniques such as SEM, EDS, FTIR, XRD, BET, XPS, UV-DRS, EIS, and zeta potential. SnO2 PHNF/UiO-66-NH2 nanocomposite offered the highest apparent rate constant of 0.0397 min−1 which was 6.3 and 3.1 times higher than those obtained for SnO2 PHNF and UiO-66-NH2, respectively. The integration of nanocomposite components revealed the synergy factor of 1.58, which can be due to the created heterojunctions resulted in efficiently charge carriers separation and retaining high redox ability. The effects of different affecting parameters such as TC initial concentration, pH of the solution, catalyst dosage, trapping agents, and coexisting anions on the catalytic performance were examined. The inhibitory effects of anions were confirmed to be decreased in the sequence of Cl− > NO3− > SO42−, while the sonocatalytic efficiency of the nanocomposite improved considerably in the presence of humic acid and bicarbonate. Also, the excellent performance of the catalyst was preserved during six successive cycles, suggesting the high stability of the prepared catalyst. In addition, based on the scavenger analysis, the created O2·−, OH·, and holes were contributed to the TC degradation. In conclusion, the creation heterojunction is an impressive methodology for improving the sonocatalytic activity of a catalyst, and SnO2 PHNF/UiO-66-NH2 nanocomposite was introduced as a satisfactory catalyst in sonocatalytic degradation of organic contaminants.

Mass Production of Multishell Hollow SiO2 Spheres With Adjustable Void Ratios and Pore Structures.

SiO2 multishell hollow spheres (MHSs) as supports have multiple porous layers and internal voids, which present notable advantages in regulating mass transport and chemical reactions. However, practical applications of SiO2 MHSs are severely hindered because of their high costs and low production efficiency issues. Herein, it is overcome these obstacles by developing a precursor hydrolysis method and demonstrate a cost-effective production of void-ratio tunable SiO2 MHSs on a large scale, which has a much lower cavitation temperature (25°C) and one order of magnitude decrease in cost. In addition, the new method can also be applied to fabricate TiO2 and SnO2 hollow spheres (HSs). In particular, an NH4Cl precipitation-pyrolysis strategy is developed to tune the pore diameters and pore distributions of SiO2 MHSs with different void ratios. SiO2 MHSs with varying void ratios and pore distributions have the broadest controlling release time ranges (30-430h). The precursor hydrolysis method and NH4Cl precipitation-pyrolysis strategy offer adequate stimulus to push forward SiO2 MHSs from laboratory-scale to industry-scale applications.

Rapid and highly sensitive gas sensing with La-doped SnO2 hollow nanospheres towards NO2 detection at room temperature

The constant challenges associated with metal oxide semiconductor (MOS) gas sensors, such as high operating temperature, low gas-sensing response, and prolonged recovery time towards NO2 restrain their practical application. Herein, we put forward a novel thought via utilizing the synergistic interplay between La doping modification and chip rapid heating treatment to solve these drawbacks. Wherein, the 3 at% La-doped SnO2 nanospheres treated at 200℃ by rapid chip heating (referred to as 3LS-200 NSs) exhibited exceptional performance. At room temperature, these nanospheres demonstrated a highly sensitive response of 3008–20 ppm NO2 within a rapid response time of 9 seconds. Furthermore, this sensor exhibited a low detection limit of 200 ppb and long-term stability. The oxygen vacancy content of 3LS-200 NSs increased by 10.8 % compared with that prepared by normal heating treatment (3LS-200NH NSs) with slow heating rate. The exceptional gas sensing properties of 3LS-200 NSs towards NO2 can be primarily attributed to the increase of oxygen vacancies, resulting in a reduced bandgap and the Fermi level shift of 0.07 eV toward the conduction band edge, hence enhancing surface electron transfer capability. This work presents a simple and energy-efficient strategy for commercial NO2 detection.

Biotemplate synthesis of SnO2 hollow porous structures for enhanced isopropanol sensing performance

Researchers are showing significant interest in the development of nanostructures with hierarchical porosity. This study introduces an eco-friendly, cost-effective, and straightforward method to create SnO2 hollow porous nanostructures using the peony as a biotemplate. A comprehensive analysis of the gas sensing characteristics of these hierarchical SnO2 hollow porous nanostructures is conducted. The results show that the gas sensor based on SnO2 showcases relatively high response values measuring 18.3 and exhibits rapid response speed of 1 s to 100 ppm isopropanol, even at a comparably low operating temperature of 180 °C. Additionally, the sensor displays good repeatability and long-term stability, which can be attributed to the inherent advantages stemming from its distinct structure. Therefore, this study provides experimental and theoretical foundations for the potential application of hollow porous SnO2 structures in sensor technology.

A concave octahedral hollow SnO2 nanocage for enhancing typical electrolyte (EMC) leakage gas sensing performance in lithium-ion batteries

The safety issues caused by lithium-ion battery (LIB) failures are the pain points that constrain the development of LIB. Developing a high sensitivity and low-cost gas sensor targeting trace electrolyte vapors, such as methyl ethyl carbonate (EMC), can help achieve early warning in accidents. Tin dioxide (SnO2) has always been one of the most widely used gas sensitive materials. Herein, the concave octahedral hollow SnO2 nanocages (SnO2-Hoc) are quickly prepared by template-engaged coordinating etching. The response value of its sensor to 10 ppm EMC is 7.24 at 140℃ and it shows sufficient sensitivity in LIB leakage simulation tests. The hollow concave octahedral structure promotes the EMC diffusion, and the lower energy barrier of EMC cleavage is the key to selective response. Overall, this work synthesized SnO2-Hoc sensor to directly detect trace EMC, which is expected to provide new guarantees for the LIB safe application.

Superior triethylamine-sensing properties based on SnO2 hollow nanospheres synthesized via one-step process

Due to serious harm of triethylamine (TEA) to environmental safety and human health, it is significant to synthesize gas-sensitive materials with high performance for TEA detection. However, it is still a challenge to achieve high-sensitivity detection of TEA at low temperature for a sensor synthesized through an economical and efficient method. In this work, hollow-structured SnO2 (HS-SnO2) nanospheres have been fabricated by a facile, low-cost hydrothermal method in one step, which exhibit superior TEA-sensing properties, including not only ultrahigh response (127.75) for 100 ​ppm TEA, good selectivity, but also fast response and recovery time (17/28 ​s), low detection threshold (1 ​ppm) and robust stability at a relatively low optimum operational temperature of 225 ​°C. The excellent gas-sensitizing performances are ascribed to porous hollow structures with rich oxygen vacancies that provide abundant active sites for raising O2 adsorption and reaction of TEA and oxygen species. This work offers an effective and economical strategy for fabricating high-performance TEA sensors for industrial applications.

High-performance bipolar membrane for CO2 electro-reduction to CO in organic electrolyte with NaOH and Cl2 produced as byproducts

Bipolar membranes (BPM) are a special class of ion-exchange membranes constituted by a cation- and an anion-exchange layer, allowing the generation of protons and hydroxide ions via water dissociation. This unique feature makes them useful in a wide range of application. In this work, we have fabricated a novel BPM, with SnO2 hollow spheres used as water dissociation catalyst. Such fabricated BPM has been served as a diaphragm to construct a three-chamber electrolyzer for CO2 electro-reduction to CO in organic electrolyte. During the long-term electrolysis process, the cathodic current density has reached to ∼96.5 mA cm−2, with the Faraday efficiency of CO stabled at ∼92.6 %. Compared with widely used commercial BPM, as-prepared BPM exhibited many advantages, such as lower hydrolysis over-potential, high catalytic efficiency and low total resistance. This technology extends the prospect of BPM application in the field of CO2 reduction.

Room-temperature NH3-sensor: SnO2@PANI core-shell hollow spheres

A novel room-temperature NH3-sensing material (SnO2@PANI core-shell hollow nanospheres) was synthesized by coating various amounts of PANI on SnO2 hollow nanospheres using a simple in-situ chemical oxidation polymerization method. The morphology and nanostructures of the synthesized sensing materials were characterized using SEM, TEM, FTIR, and XRD. Gas-sensing tests demonstrate that SP-5 exhibits the highest response to NH3 at room temperature, with a response value (26.48 at 500 ppm) more than 6 times higher than that of pure PANI (4.35). This sensor displays excellent selectivity, with good anti-interference capability to CO and NO2. The improved sensing performance of the core-shell hollow structure is attributed to the unique structure and p-n heterojunction between PANI and SnO2, which is confirmed by EIS spectra.

High Sensitivity Ethanol Gas Sensor Based on Hollow F-Doped SnO₂ Nanofibers

High Sensitivity Ethanol Gas Sensor Based on Hollow F-Doped SnO₂ Nanofibers

Low-loaded Ru on hollow SnO2 for enhanced electrocatalytic hydrogen evolution.

In response to the challenges of intermediate poisoning and the high cost of noble metal catalysts in the hydrogen evolution reaction (HER), we develop a Ru-doped SnO2 catalyst. This Ru-SnO2 catalyst has the characteristics of low Ru loading and a hollow structure, which endow it with good electrocatalytic activity and stability for the HER.

Dual-functional, highly efficient CaIn2S4/PDA@SnO2 photocatalyst with Z-Scheme for photocatalytic hydrogen production from water splitting and organic pollutant degradation

Heterojunction can be used to develop semiconductor catalysts with high photocatalytic activity. In this work, a Z-Scheme CaIn2S4(CIS)/PDA@SnO2 photocatalyst was successfully synthesized. Firstly, SnO2 hollow nanospheres were prepared by hydrothermal method. On this basis, SnO2 hollow nanospheres wrapped by polydopamine (PDA) were obtained via self-polymerization of dopamine. Finally, the CIS/PDA@SnO2 composites were synthesized via a one-step oil bath method. The heterojunction has successfully achieved effective separation of electron-hole pairs. PDA acted as a photosensitizer and an electron transfer medium in the heterojunction. Multiple characterization techniques such as XRD, SEM, TEM, BET, XPS, PL, UV–vis DRS, EPR and photoelectrochemical measurements were used for material structure and performance analysis. The photocatalytic performance of the photocatalysts was tested by photocatalytic hydrogen production from water splitting and RhB solution degradation. A flower-like close contact between CaIn2S4 and PDA@SnO2 interfaces can be obviously observed via SEM and TEM images. The band gap energies (Eg) of CaIn2S4 and PDA@SnO2 are 2.06 eV and 3.74 eV. CaIn2S4/PDA@SnO2-1(CPS-1) exhibits stronger light absorption together with lower transfer resistance compared to other samples. CPS-1 showed excellent photocatalytic hydrogen production and RhB degradation performance. Furthermore, the results of active species capture experiments, Mott-Schottky curve, XPS measurement and other tests show that it is logical to use the Z-Scheme charge mobility process to explain the better photocatalytic activity of the CIS/PDA@SnO2 composite. This work will present an efficient option for the fabrication of Z-Scheme heterojunctions and possibly further develop a new avenue for the control of the structure of semiconductor photocatalysts.

Fabrication of selective and highly sensitive triethylamine gas sensor using In2O3–SnO2 hollow nanospheres in room temperature activated by UV irradiation

Introducing a groundbreaking solution, a room-temperature (RT, 25 °C) gas sensor addresses complexities in conventional sensors, promising enhanced performance. Synthesized through hydrothermal and thermal calcination processes, SnO2 hollow nanospheres (HNs) are integrated with In2O3 components to bolster sensing capabilities. The sensor detects triethylamine (TEA) gas upon UV light irradiation, owing to its unique surface properties and SnO2–SnO2 and SnO2–In2O3 homo- and heterojunctions. This results in unparalleled sensitivity to TEA gas (Ra/Rg = 34–100 ppm) and an exceptional limit of detection (3.98 ppt), attributed to photo-ionized O2− ions' heightened reactivity. The study proposes superior sensors backed by comprehensive analyses, demonstrating their performance improvements and underlying mechanisms. The optimized sensor design, based on In2O3-appended SnO2 HNs, presents exceptional selectivity, pattern recognition for low TEA gas concentrations, humidity resistance, and reliability under UV irradiation.

Morphological features and electrical properties of hollow SnO2 for room temperature CO sensing

This work highlights the synthesis of hollow SnO2 nanostructures by hydrothermal method and investigation of their morphological features, crystal structure, surface area, elemental composition, and change in resistance to gas as the electrical properties. The synthesis of hollow SnO2 nanostructures was accomplished by using a modified hydrothermal method starting with a core@shell SiO2 template, and its nanostructure properties were compared with a SiO2@SnO2 and template-free SnO2. The STEM analysis revealed that the SnO2 nanomaterials had a spherical morphology. The crystallite diameters of the hollow and template-free SnO2 spheres were 3.3, and 4.6 nm, respectively, and their optical bandgap energies were determined to be 4.10, and 3.90 eV, respectively, indicating the influence of quantum confinement effects. The compositions of the SiO2@SnO2 and the hollow SnO2 nanomaterials were ascertained by XPS studies, which confirmed the purity of SnO2. By a simple sensing test, the hollow SnO2 structures were utilized in the sensing of CO at room temperature and the sensor response was found to be six times higher than that of the template-free SnO2 spheres due to their lower domain size and a large number of active sites. This study indicates that the hollow SnO2 obtained from a core@shell SiO2 template has the potential to become a viable sensor material for CO detection at room temperature.

High sensitivity and surface mechanism of MOFs-derived metal oxide Co3O4-SnO2 hollow spheres to ethanol

Metal-organic Frameworks (MOFs) have been widely studied due to their high porosity and large surface area. In this paper, Co3O4-modified SnO2 hollow spheres with excellent ethanol gas sensitivity were prepared by using ZIF-67 as template by two-step hydrothermal pyrolysis at 300 °C. The elemental composition, morphology, structure and gas sensitivity properties of the materials were characterized by XRD, SEM and gas-sensitive analysis system. The experiment shows that the ZIF-67-derived Co3O4-SnO2 composite has a response value of 33.9 to 100 ppm ethanol gas at the optimum operating temperature of 225 °C, which is significantly higher than that of pure SnO2. According to the characteristics of gas sensitivity and morphology, the enhancement of gas sensitivity is due to the increase of oxygen vacancies, which promotes oxygen adsorption and surface chemical reaction.

Synthesis of Semiconductor SnO2 Hollow Nanosphere; Their Modified Electrode for Electrochemical Reduction and Determination of Hydrogen Peroxide, Ethanol and Oxidation of Bioactive Molecules

Synthesis of Semiconductor SnO2 Hollow Nanosphere; Their Modified Electrode for Electrochemical Reduction and Determination of Hydrogen Peroxide, Ethanol and Oxidation of Bioactive Molecules

Lychee-like SnO2 hollow microspheres sensitized by carbon quantum dots for high-sensitivity ethanol sensor

In this work, the application of carbon quantum dots as known as CQDs for ethanol detection is pioneered, and a multi-fold improvement in gas sensor performance is achieved through the unique electron transport mechanism of carbon quantum dots. The lychee-like SnO2 hollow microspheres and CQDs are prepared by a solvent heat method. The composites are assembled by rapid grinding, ultrasonication, and stirring. The minimum detection limit is 500 ppb. The response/recovery time of the best mass percentage composite is 9 s/16 s to ethanol at 100 ppm with an optimum working temperature of 216℃ in the target gas-sensitive test. Such a fast response speed improvement is ascribed to the excellent electron transfer efficiency of the 5 nm diameter carbon quantum dots (CQDs).

Preparation of Gas Sensors by Hollow SnO2 Electrospun Nanofibers

This work investigated the preparation of tin dioxide (SnO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> ) nanofibers with hollow structures by combining the electrostatic spinning technique with the calcination process. The morphology was observed by X-ray diffraction, field emission scanning electron microscopy (FESEM), and characterization of the chemical state of the elements using X-ray photoelectron spectroscopy (XPS). In gas-sensitive tests on various gases, we found that the response of SnO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> hollow nanofibers to ethanol at a concentration of 100ppm reached 27.13 when the temperature reached 350°C as the optimum temperature. Response and recovery times were 42s and 35s, respectively, and the theoretical detection limit of the sensor was as low as 2.944ppm. For the enhanced response, the adsorption mechanism of ethanol gas could be attributed to electron transfer on the surface of tin dioxide and followed through impedance change. With the help of DFT calculations, we demonstrate that the adsorption mechanism of ethanol gas is due to the impedance change caused by the electron transfer on the surface of tin dioxide, which is more selective with ethanol gas.

Resistive-type sensors based on few-layer MXene and SnO2 hollow spheres heterojunctions: Facile synthesis, ethanol sensing performances

High-performance and low-cost gas sensors are highly desirable and involved in industrial production and environmental detection. The combination of highly conductive MXene and metal oxide materials is a promising strategy to further improve the sensing performances. In this study, the hollow SnO2 nanospheres and few-layer MXene are assembled rationally via facile electrostatic synthesis processes, then the SnO2/Ti3C2Tx nanocomposites were obtained. Compared with that based on either pure SnO2 nanoparticles or hollow nanospheres of SnO2, the SnO2/Ti3C2Tx composite-based sensor exhibits much better sensing performances such as higher response (36.979), faster response time (5 s), and much improved selectivity as well as stability (15 days) to 100 ppm C2H5OH at low working temperature (200 °C). The improved sensing performances are mainly attributed to the large specific surface area and significantly increased oxygen vacancy concentration, which provides a large number of active sites for gas adsorption and surface catalytic reaction. In addition, the heterostructure interfaces between SnO2 hollow spheres and MXene layers are beneficial to gas sensing behaviors due to the synergistic effect.

SnO2 @ZnS core-shell hollow spheres with enhanced room-temperature gas-sensing performance

To detect flammable gases and lower energy consumption, room-temperature gas sensors with high sensitivity, selectivity and stability have attracted increasing attention. In this work, SnO2 @ZnS core-shell hollow spheres are prepared via a two-step hydrothermal method. The effects of morphology and composition on gas sensing performance were systematically investigated by adjusting the molar ratio of SnO2 to ZnS. Compared with pure SnO2 hollow spheres, the core-shell composites exhibit excellent enhanced sensing properties to n-butanol at room temperature. The SnO2 @ZnS (1:0.5) core-shell hollow spheres show the highest sensing response (12.6) to 100 ppm n-butanol at 25ºC, which was ∼4 times higher than that of the pristine SnO2 hollow spheres. The room-temperature sensing mechanism to n-butanol is proposed. The enhanced sensing mechanism of the core-shell structure is attributed to i) the uniform hollow structure, ii) the electron transfer to surface induced by SnO2 metallization and the formation of n-n heterojunction, and iii) high charge carrier density and fast charge transfer rate. This study provides a novel core-shell hollow structure for room-temperature detection of n-butanol.

MOF-Derived SnO2 hollow spheres for Acetone Gas Sensing

MOF-Derived SnO2 hollow spheres for Acetone Gas Sensing