Metastable tin oxide electrode for efficient electrochemical CO₂ Reduction to formate

장정환,정주원,강진수,성영은 한국공업화학회 2020 한국공업화학회 연구논문 초록집 Vol.2020 No.-

Electrochemical reduction of carbon dioxide is promising way to convert Carbon dioxide into valuable products. Among these products, formate is economically viable due to its simple reaction pathway and relatively high energy value. Therefore, tin-based materials have received attention as they show high performance in formate production. In this work, we synthesized metastable tin oxide electrode by anodization and thermal annealing. Tin oxide electrode enhances its electrochemical double layer capacitance by anodization and becomes highly crystalline after thermal annealing. Electrochemical measurements show its high faradaic efficiency of 60% for CO₂ reduction to formate at -0.8 V. It also exhibits a excellent formate partial current density of 33.66mA/㎠. According to various spectroscopic analyses, tin oxide remains its metastable SnO₂ phase at quite reductive potential of -0.8 V due to its cyrstalline structure by thermal annealing.

Impedance Spectroscopy and Structural Properties of SnO2/SiO2 Thin Films

정진 한국물리학회 2021 새물리 Vol.71 No.7

Tin-dioxide (SnO2) thin films were prepared by using radio-frequency sputtering. An X-ray diffraction analysis revealed that the samples were crystallized to form a tetragonal structure. The interface between the substrate and the thin films of the prepared samples was investigated using transmission electron microscopy (TEM). As the deposition time was increased, the thickness of the SnO2 thin film increased and its resistance increased constantly. Energy dispersive X-ray spectroscopy confirmed the composition of the samples. Moreover, TEM showed that a SiO2 layer was grown between the substrate and the SnO2 thin-film layer. The electrical properties of the thin film were closely related to oxygen defects between the surface and the interface of the thin film, as was confirmed by electrochemical impedance spectroscopy.

Nitrogen-plasma Treatment of Parallel-aligned SnO2-nanowire Field-effect Transistors

최용희,나준홍,김재성,주민규,김규태,강필수 한국물리학회 2014 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.65 No.4

Nitrogen (N2)-plasma treatment and polymethylmethacrylate (PMMA) passivation were carriedout to stabilize the electrical properties of parallel-aligned tin-dioxide (SnO2)-nanowire field-effecttransistors. Treatment led to a positive shift in the threshold voltage, Vth, with a reduction inthe hysteresis in the transfer curves of more than 30% compared to the case without treatment. Passivation was carried using a PMMA coating to prevent changes in the electrical properties overtime. X-ray photoelectron spectroscopy and Auger electron spectroscopy were employed to determinethe chemical mechanisms that resulted in the changes in the electrical properties over time,those changes being attributed to the recombination of oxygen vacancies and carbon contaminantson the surface of the SnO2 nanowires with oxygen in the ambient air.

The structural and electrical properties of fluorine-doped tin dioxide ceramics Prepared by spark plasma sintering (SPS)

S. Malek,S. Baghshahi,R. Sarraf-Mamoory,Ali Nemati 한양대학교 세라믹연구소 2017 Journal of Ceramic Processing Research Vol.18 No.12

In this work, fluorine-doped tin dioxide ceramics were prepared by spark plasma sintering. In order to obtain a thin layer offluorine-doped tin dioxide with high electrical conductivity and high optical transparency in the sputtering method, it isnecessary to prepare a high density and high electrical conductivity target. To do so, tin dioxide powder and tin (II) fluoridepowder were utilized to prepare the target. The concentration of fluorine was selected based on the mass ratio of tin (II)fluoride to tin dioxide and ranged between 0.04 and 0.24 (with 0.04 increments). After the powders were mixed, the target wasmade using spark plasma sintering. The best target had a mass ratio of tin (II) fluoride to tin dioxide of 0.16, with a relativedensity of 97% and an electrical resistance of 3 × 10−4 Ω.cm. This provided a suitable candidate for a target when using thesputtering method.

First-principles study of energy transport in tin oxynitride lattice

Kwon Choah,Kim Hyeonwoo,Lee Ho,Kim Sangtae 한국물리학회 2023 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.82 No.3

Tin dioxide (SnO2) based devices require thermal management for safety and performance. Tin oxynitrides are considered a new class of material that can potentially tune the physicochemical properties of SnO2. Here, we investigate the energy transport in SnO2 polymorphs, Sn3N4, and SnO2–xNx oxynitrides with various compositions (x=0.34, 0.5, 0.66, 1.00, 1.34, 1.50, and 1.66) utilizing frst principles-based phonon calculations. The phonon dispersion curves of the materials extract the phonon energy and group velocity, which determines the energy transport in the lattices. N-rich SnO2–xNx has unique stretching motions of N2 dimers near 25 THz. The group velocity of SnO2–xNx in the high-frequency region decreases as the nitrogen content (x) in SnO2–xNx increases; the lowered group velocity originates from the slow-moving N atoms. The combined results explain the change in the energy transport as the N concentration increases in SnO2–xNx by comparing the contributions of the small group velocity to those of the phonon energy for distinct vibrational modes.

1P-170 Synthesis of Tin dioxide (SnO₂) nanoparticle using sonochemical method with photocatalysis behavior

정운호,김종규,유정열,김우석,박선아,이유로,김은비,하태훈,이탁재 한국공업화학회 2017 한국공업화학회 연구논문 초록집 Vol.2017 No.1

In this study, tin dioxide nanoparticles (SnO₂) were synthesized by using sonochemical method. The advantage of using this method is that it creates localized cavitation which when the cavitation disintegrates, hot spot is formed that creates tremendously high temperature and pressure not to mention the ease in using it. The resultant white gel-like solution was sonicated separately each for 30, 60, 90, 120 minutes. After being dried, samples were calcined at 400°C for 1.5 hours for better crystalline. The crystallinity of NPs was confirmed by X-Ray diffraction, and their crystal phases on each sonication time were analyzed by scanning electron microscope. The photocatalysis behavior of each NPs in different sonication time was shown by UV irradiation using Rhodamine B. indicating the best time.

Ultra-sensitive hydrogen gas sensors based on Pd-decorated tin dioxide nanostructures: Room temperature operating sensors

Lee, Jun Min,Park, Ji-eun,Kim, Seri,Kim, Sol,Lee, Eunyoung,Kim, Sung-Jin,Lee, Wooyoung Elsevier 2010 INTERNATIONAL JOURNAL OF HYDROGEN ENERGY - Vol.35 No.22

<P><B>Abstract</B></P><P>We have investigated the fabrication of hydrogen gas sensors based on networks of Pd nanoparticles (NPs) deposited tin dioxide nanowires (NWs). SnO<SUB>2</SUB> NWs with tin NPs attached on the surface were obtained by a simple thermal evaporation of SnO crystalline powders. The tin dioxide NWs were decorated with Pd NPs by the reduction process in Pd ion solution. The sensors showed ultra-high sensitivity (∼1.2 × 10<SUP>5</SUP>%) and fast response time (∼2 s) upon exposure to 10,000 ppm H<SUB>2</SUB> at room temperature. These sensors were also found to enable a significant electrical conductance modulation upon exposure to extremely low concentrations (40 ppm) of H<SUB>2</SUB> in the air. Our fabrication method of sensors combining with Pd NPs, Sn NPs and n-type semiconducting SnO<SUB>2</SUB> NWs allows optimized catalytic and depletion effect and results the production of highly-sensitive H<SUB>2</SUB> sensors that exhibit a broad dynamic detection range, fast response times, and an ultra-low detection limit.</P>

A simple fabrication of porous carbon@tin dioxide as anode material for achieving lithium‑ion batteries with high performance

Panjing Zeng,Chaomin Zhang,Mengzhao Ding,Yuchen Huang 한국탄소학회 2023 Carbon Letters Vol.33 No.6

Refined structured tin dioxide gets the amount of attraction because of its low cost and stability. The C@SnO2 nanospheres with mesoporous structures were produced using the hard template method in this work. The C@SnO2 is primarily gained attributed to the dehydration condensation of C6H12O6 and the hydrolysis of SnCl4 ·5H2O. The morphology of the C@SnO2 was analyzed by physical characterization and the diameter of the obtained C@SnO2 was around 138 nm. When C@SnO2 was applied to lithium-ion batteries as anode material, it performed outstanding electrochemical properties, with a capacity of 735 and 539 mA h g? 1 maintained at 1000 and 2000 mA g? 1, respectively. Furthermore, it exhibits favorable discharge/ charge cycle stability. This is probably because of the more chemically redox active sites provided by C@SnO2 nanocomposites and it also allows fast ion diffusion and electron migration.

Optical Study of Bulk and Thin-film Tin Dioxide

장형근,박준우,김성,최석호,이호선 한국물리학회 2012 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.61 No.12

We grew nano-crystalline SnO₂ thin films on Si substrates by using RF magnetron sputtering deposition method. We examined the microstructure of the SnO₂ thin films via X-ray diffraction (XRD) and the optical properties of the SnO₂ thin films via photoluminescence (PL) spectroscopy and spectroscopic ellipsometry. We obtained the dielectric functions (ε = ε₁ + <i>i</i>ε₂) of the SnO₂ thin films in the visible to deep ultraviolet spectral range, as well as the anisotropic dielectric functions of the bulk SnO₂ single crystal. The band edge blue shift and the larger peak maximum of ε_2z compared to those of ε_2x, in the directions parallel and perpendicular to the optical c-axis, respectively, are consistent with calculations found in the literature. We estimated the critical point energies by using the second derivatives of the dielectric functions with respect to energy, and the results matched well with the calculated band structures in the literature. We also found critical point energies in the experimental data which were forbidden by selection rules in the calculations. The PL study of the SnO₂ thin films and bulk single crystals showed similar PL peaks associated with the band gap energy, suggesting that even the RT-grown thin film contained a very small number of crystalline nanograins even though the XRD spectra did not show any crystalline peaks.

열처리에 따른 SnO₂ 박막의 표면형상

박경희,류현욱,서용진,이우선,홍광준,박진성,Park, Kyung-Hee,Ryu, Hyun-Wook,Seo, Yong-Jin,Lee, Woo-Sun,Hong, Kwang-Jun,Park, Jin-Seong 한국재료학회 2003 한국재료학회지 Vol.13 No.7

Tin dioxide ($SnO _2$) thin films were deposited at $375^{\circ}C$ on alumina substrate by metal-organic chemical vapor deposition. A few hillocks like a cauliflower were observed and the number of hillock on thin film surface increased with annealing temperature in air atmosphere. The oxygen content and the binding energy during air annealing at$ 500^{\circ}C$ came to close the stoichiometric $SnO_2$. The cauliflower hillocks seem to be the result of the continuous migration of the tiny grains to release the stress of an expanded grain. Sensitivity of CO gas depended on annealing temperature and increased with increasing annealing temperature.