scholarly journals Elucidation of the Crystal Growth Characteristics of SnO2 Nanoaggregates Formed by Sequential Low-Temperature Sol-Gel Reaction and Freeze Drying

Nanomaterials ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1738
Author(s):  
Saeid Vafaei ◽  
Alexander Wolosz ◽  
Catlin Ethridge ◽  
Udo Schnupf ◽  
Nagisa Hattori ◽  
...  
Keyword(s):  
Crystal Growth ◽  
Low Temperature ◽  
Photoelectron Spectroscopy ◽  
High Performance ◽  
Freeze Drying ◽  
Sno2 Nanoparticles ◽  
Sol Gel ◽  
Functional Materials ◽  
Cost Effective ◽  
High Concentration

SnO2 nanoparticles are regarded as attractive, functional materials because of their versatile applications. SnO2 nanoaggregates with single-nanometer-scale lumpy surfaces provide opportunities to enhance hetero-material interfacial areas, leading to the performance improvement of materials and devices. For the first time, we demonstrate that SnO2 nanoaggregates with oxygen vacancies can be produced by a simple, low-temperature sol-gel approach combined with freeze-drying. We characterize the initiation of the low-temperature crystal growth of the obtained SnO2 nanoaggregates using high-resolution transmission electron microscopy (HRTEM). The results indicate that Sn (II) hydroxide precursors are converted into submicrometer-scale nanoaggregates consisting of uniform SnO2 spherical nanocrystals (2~5 nm in size). As the sol-gel reaction time increases, further crystallization is observed through the neighboring particles in a confined part of the aggregates, while the specific surface areas of the SnO2 samples increase concomitantly. In addition, X-ray photoelectron spectroscopy (XPS) measurements suggest that Sn (II) ions exist in the SnO2 samples when the reactions are stopped after a short time or when a relatively high concentration of Sn (II) is involved in the corresponding sol-gel reactions. Understanding this low-temperature growth of 3D SnO2 will provide new avenues for developing and producing high-performance, photofunctional nanomaterials via a cost-effective and scalable method.

scholarly journals High-Performance Humidity Sensor Based on the Graphene Flower/Zinc Oxide Composite

Nanomaterials ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 242
Author(s):  
Muhammad Saqib ◽  
Shenawar Ali Khan ◽  
Hafiz Mohammad Mutee Ur Rehman ◽  
Yunsook Yang ◽  
Seongwan Kim ◽  
...  
Keyword(s):  
Zinc Oxide ◽  
High Performance ◽  
Humidity Sensor ◽  
Electronic Device ◽  
Sol Gel ◽  
Functional Materials ◽  
Cost Effective ◽  
Functional Material ◽  
Functional Layer ◽  
Highly Sensitive

Performance of an electronic device relies heavily on the availability of a suitable functional material. One of the simple, easy, and cost-effective ways to obtain novel functional materials with improved properties for desired applications is to make composites of selected materials. In this work, a novel composite of transparent n-type zinc oxide (ZnO) with a wide bandgap and a unique structure of graphene in the form of a graphene flower (GrF) is synthesized and used as the functional layer of a humidity sensor. The (GrF/ZnO) composite was synthesized by a simple sol–gel method. Morphological, elemental, and structural characterizations of GrF/ZnO composite were performed by a field emission scanning electron microscope (FESEM), energy-dispersive spectroscopy (EDS), and an x-ray diffractometer (XRD), respectively, to fully understand the properties of this newly synthesized functional material. The proposed humidity sensor was tested in the relative humidity (RH) range of 15% RH% to 86% RH%. The demonstrated sensor illustrated a highly sensitive response to humidity with an average current change of 7.77 μA/RH%. Other prominent characteristics shown by this device include but were not limited to high stability, repeatable results, fast response, and quick recovery time. The proposed humidity sensor was highly sensitive to human breathing, thus making it a promising candidate for various applications related to health monitoring.

Use of anti-solvent to enhance thermoelectric response of hybrid-halide perovskite thin films

2022 ◽  
Author(s):  
Shrikant SAINI ◽  
Izuki Matsumoto ◽  
Sakura Kishishita ◽  
Ajay Kumar Baranwal ◽  
Tomohide Yabuki ◽  
...  
Keyword(s):  
Thin Films ◽  
Electrical Conductivity ◽  
Photoelectron Spectroscopy ◽  
High Performance ◽  
Cost Effective ◽  
Performance Tuning ◽  
Charge Carrier Density ◽  
X Ray ◽  
Thermoelectric Energy Harvesting ◽  
Halide Perovskite

Abstract Hybrid halide perovskite has been recently focused on thermoelectric energy harvesting due to the cost-effective fabrication approach and ultra-low thermal conductivity. To achieve high performance, tuning of electrical conductivity is a key parameter that is influenced by grain boundary scattering and charge carrier density. The fabrication process allows tuning these parameters. We report the use of anti-solvent to enhance the thermoelectric performance of lead-free hybrid halide perovskite, CH3NH3SnI3, thin films. Thin films with anti-solvent show higher connectivity in grains and higher Sn+4 oxidation states which results in enhancing the value of electrical conductivity. Thin films were prepared by a cost-effective wet process. Structural and chemical characterizations were performed using x-ray diffraction, scanning electron microscope, and x-ray photoelectron spectroscopy. The value of electrical conductivity and the Seebeck coefficient were measured near room temperature. The high value of power factor (1.55 µW/m.K2 at 320 K) was achieved for thin films treated with anti-solvent.

Fast response acetone-sensing properties of SnO2 nanoparticles prepared by the sol-gel method

2021 ◽  
Vol 93 (3) ◽  
pp. 30401
Author(s):  
Jiaxing Wang ◽  
Hai Yu ◽  
Yong Zhang
Keyword(s):  
High Performance ◽  
Gas Sensing ◽  
Sno2 Nanoparticles ◽  
Sol Gel ◽  
Fast Response ◽  
X Ray Diffraction ◽  
Gel Method ◽  
Sol Gel Method ◽  
Short Recovery Time ◽  
Acetone Gas Detection

SnO2 nanoparticle architectures were successfully synthesized using a sol-gel method and developed for acetone gas detection. The morphology and structure of the particles were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The SnO2 nanoparticle architectures were configured as high-performance sensors to detect acetone and showed a very fast response time (<1 s), a short recovery time (10 s), good repeatability and high selectivity at a relatively low working temperature. Thus, SnO2 nanoparticles should be promising candidates for designing and fabricating acetone gas sensors with good gas sensing performance. The possible gas sensing mechanism is also presented.

scholarly journals Mode Sensitivity Exploration of Silica–Titania Waveguide for Refractive Index Sensing Applications

Sensors ◽  
2021 ◽  
Vol 21 (22) ◽  
pp. 7452
Author(s):  
Muhammad A. Butt ◽  
Andrzej Kaźmierczak ◽  
Cuma Tyszkiewicz ◽  
Paweł Karasiński ◽  
Ryszard Piramidowicz
Keyword(s):  
Refractive Index ◽  
High Performance ◽  
Near Infrared ◽  
Sol Gel ◽  
Cost Effective ◽  
Dip Coating ◽  
Infrared Wavelength ◽  
Refractive Index Sensing ◽  
Sensing Applications ◽  
Coating Method

In this paper, a novel and cost-effective photonic platform based on silica–titania material is discussed. The silica–titania thin films were grown utilizing the sol–gel dip-coating method and characterized with the help of the prism-insertion technique. Afterwards, the mode sensitivity analysis of the silica–titania ridge waveguide is investigated via the finite element method. Silica–titania waveguide systems are highly attractive due to their ease of development, low fabrication cost, low propagation losses and operation in both visible and near-infrared wavelength ranges. Finally, a ring resonator (RR) sensor device was modelled for refractive index sensing applications, offering a sensitivity of 230 nm/RIU, a figure of merit (FOM) of 418.2 RIU−1, and Q-factor of 2247.5 at the improved geometric parameters. We believe that the abovementioned integrated photonics platform is highly suitable for high-performance and economically reasonable optical sensing devices.

scholarly journals Ultralow-temperature-driven water-based sorption refrigeration enabled by low-cost zeolite-like porous aluminophosphate

2022 ◽  
Vol 13 (1) ◽  
Author(s):  
Zhangli Liu ◽  
Jiaxing Xu ◽  
Min Xu ◽  
Caifeng Huang ◽  
Ruzhu Wang ◽  
...  
Keyword(s):  
Low Temperature ◽  
Water Sorption ◽  
High Performance ◽  
Global Climate ◽  
Low Cost ◽  
Cost Effective ◽  
High Water ◽  
Coefficient Of Performance ◽  
High Efficient ◽  
Water Based

AbstractThermally driven water-based sorption refrigeration is considered a promising strategy to realize near-zero-carbon cooling applications by addressing the urgent global climate challenge caused by conventional chlorofluorocarbon (CFC) refrigerants. However, developing cost-effective and high-performance water-sorption porous materials driven by low-temperature thermal energy is still a significant challenge. Here, we propose a zeolite-like aluminophosphate with SFO topology (EMM-8) for water-sorption-driven refrigeration. The EMM-8 is characterized by 12-membered ring channels with large accessible pore volume and exhibits high water uptake of 0.28 g·g−1 at P/P0 = 0.2, low-temperature regeneration of 65 °C, fast adsorption kinetics, remarkable hydrothermal stability, and scalable fabrication. Importantly, the water-sorption-based chiller with EMM-8 shows the potential of achieving a record coefficient of performance (COP) of 0.85 at an ultralow-driven temperature of 63 °C. The working performance makes EMM-8 a practical alternative to realize high-efficient ultra-low-temperature-driven refrigeration.

scholarly journals One-Step Synthesis, Structure, and Band Gap Properties of SnO2 Nanoparticles Made by a Low Temperature Nonaqueous Sol–Gel Technique

ACS Omega ◽  
2018 ◽  
Vol 3 (10) ◽  
pp. 13227-13238 ◽  
Author(s):  
Mohamed Karmaoui ◽  
Ana Belen Jorge ◽  
Paul F. McMillan ◽  
Abil E. Aliev ◽  
Robert C. Pullar ◽  
...  
Keyword(s):  
Low Temperature ◽  
Band Gap ◽  
Sno2 Nanoparticles ◽  
Sol Gel ◽  
One Step ◽  
Gel Technique

Low-temperature, high-performance solution-processed metal oxide thin-film transistors formed by a ‘sol–gel on chip’ process

2010 ◽  
Vol 10 (1) ◽  
pp. 45-50 ◽  
Author(s):  
K. K. Banger ◽  
Y. Yamashita ◽  
K. Mori ◽  
R. L. Peterson ◽  
T. Leedham ◽  
...  
Keyword(s):  
Thin Film ◽  
Low Temperature ◽  
Metal Oxide ◽  
Thin Film Transistors ◽  
High Performance ◽  
Sol Gel ◽  
Oxide Thin Film ◽  
Solution Processed ◽  
Metal Oxide Thin Film ◽  
On Chip

Composition and Chemical Structure of Nitrided Silica Gel

1984 ◽  
Vol 32 ◽  
Author(s):  
R. K. Brow ◽  
C. G. Pantano
Keyword(s):  
Thin Films ◽  
Infrared Spectroscopy ◽  
Low Temperature ◽  
Silica Gel ◽  
Photoelectron Spectroscopy ◽  
Chemical Structure ◽  
Sol Gel ◽  
X Ray ◽  
Higher Temperature ◽  
Low Temperature Treatments

ABSTRACTSol/gel derived silica thin films were thermally treated in NH3 for four hours at temperatures up to 1300C. The films were analyzed by ellipsometry, X-ray photoelectron spectroscopy (XPS) and infrared spectroscopy (IR). Over 30 mol% nitrogen was incorporated in the film treated at 1300C. Using IR and XPS analyses, -NHx groups were found to be present after low temperature treatments, while nitrogen was incorporated in an oxynitride structure after the higher temperature treatments.

scholarly journals Synthesis & characterization of nanostructure VO2 thin film

2021 ◽  
Vol 2070 (1) ◽  
pp. 012098
Author(s):  
P K Ojha ◽  
S K Mishra
Keyword(s):  
Thin Films ◽  
Photoelectron Spectroscopy ◽  
Vanadium Dioxide ◽  
Sol Gel ◽  
Cost Effective ◽  
Metallic Phase ◽  
Strongly Correlated ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sol Gel Process

Abstract Vanadium dioxides are strongly correlated systems which undergo an insulator-metal transition (IMT) from a low-temperature semiconducting phase to a high-temperature metallic phase. Among them, Vanadium dioxide (VO2) undergoes IMT close to room temperature, accompanied by a structural transition resulting change of several orders of magnitude in the electrical and optical properties. Here, we present the synthesis of VO2 by sol-gel process which employs cost-effective precursors to synthesize pure phase of VO2 thin films. The synthesized thin films were characterized using an X-ray diffraction (XRD) to confirm phase purity and high resolution scanning electron microscope (HR-SEM) to study the crystallite and particle size for the synthesized films. The film’s surface was analyzed by X-ray photoelectron spectroscopy (XPS) to determine the valence state and chemical composition of vanadium dioxide.

Manufactory and Properties of Poly(p-Phenylenebenzobisoxazole) Aerogels Prepared by a Simple Freeze-Drying Procedure

2020 ◽  
Vol 993 ◽  
pp. 662-668
Author(s):  
Yu Nong Wei ◽  
Guang Li ◽  
Sheng Lin Yang ◽  
Jun Hong Jin
Keyword(s):  
High Performance ◽  
Freeze Drying ◽  
Sol Gel ◽  
Fire Retardant ◽  
Decomposition Temperature ◽  
High Specific Surface Area ◽  
High Porosity ◽  
Cellulose Aerogel ◽  
Small Pore ◽  
Small Pore Diameter

Aerogels based on organic high performance fibers have been attracted great attention due to its excellent thermal and mechanical properties. Here, PBO nanofiber aerogel were prepared from the super-fiber PBO through a top-down process with a sol-gel process and a simple freeze-drying process, followed by thermal cross-linking. The prepared aerogel has a small volume shrinkage, a high specific surface area of 168.9 m2 /g and a small pore diameter of 1.356 nm. Because of its 3D porous structure, it results in a low density of 6 to 30 mg/cm3 and a high porosity (98%). The aerogel retains the molecular structure of PBO at the same time, which gives it initial thermal decomposition temperature up to 500 °C and a superior fire-retardant capability. PBO aerogel possesses good compressive properties with a yield stress of 0.44MPa at 80% strain and an elasticity modulus of 1.98 MPa which is higher than SiO2 and cellulose aerogel reported.

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