• Title/Summary/Keyword: Vanadium pentoxide

Search Result 35, Processing Time 0.03 seconds

Dissolution of vanadium pentoxide using microwave digestion system for determination of vanadium by ICP-AES (ICP-AES로 바나듐 측정을 위한 마이크로파 용해 장치를 이용한 오산화바나듐 용해)

  • Choi, Kwang-Soon;Park, Yang-Soon;Kim, Yeon-Hee;Han, Sun-Ho;Song, Kyu-Seok
    • Analytical Science and Technology
    • /
    • v.23 no.6
    • /
    • pp.511-517
    • /
    • 2010
  • Dissolution procedure of vanadium pentoxide, which is widely used as a catalyst for production of sulfuric acid or an oxide reaction of the numerous organic compounds, was investigated. Reagent of vanadium pentoxide was completely dissolved in aqua regia-$H_2O_2$-HF solution, but plate type of vanadium pentoxide sample was not clearly dissolved with mixed acids. Thus, in order to establish the dissolution procedure for plate type of vanadium pentoxide, the solubility of vanadium pentoxide was investigated through comparison of acid treatment-fusion and microwave digestion methods. The optimized acid for dissolution of vanadium compound was found to be mixing acids of aqua regia, $H_2O_2$ and HF. Acid-fusion and microwave digestion methods have a similar property in the solubility of vanadium compound, but the latter was more quick and convenient procedure. The content of vanadium pentoxide was found to be $97.9{\pm}0.9%$ using an inductively coupled plasma atomic emission spectrometer after dissolution of a sample with the microwave digestion system.

Atomic Layer Deposition of Vanadium Pentoxide on Carbon Electrode for Enhanced Capacitance Performance in Capacitive Deionization

  • Chung, Sangho;Bong, Sungyool;Lee, Jaeyoung
    • Applied Chemistry for Engineering
    • /
    • v.33 no.3
    • /
    • pp.315-321
    • /
    • 2022
  • We firstly observed that activated carbon (AC) deposited by atomic-layer vanadium pentoxide (V2O5) was used as CDI electrodes to utilize the high dielectric constant for enhancing the capacitance equipped with atomic layer deposition (ALD). It was demonstrated that the vanadium pentoxide (V2O5) with sub-nanometer layer was effectively deposited onto activated carbon, and the electric double-layer capacitance of the AC was improved due to an increase in the surface charge density originated from polarization, leading to high ion removal in CDI operation. It was confirmed that the performance of modified-AC increases more than 200%, comparable to that of pristine-AC under 1.5 V at 20 mL min-1 in CDI measurements.

Manufacture of Vanadium pentoxide and nickel sulfate from heavy oil fly ash

  • Park, Gyeong-Ho
    • Resources Recycling
    • /
    • v.2 no.4
    • /
    • pp.23-26
    • /
    • 1993
  • This work is carried out to develop the recovery process of vanadium as vanadium pentoxide and nickel as nickel sulphate from the leaching solution of heavy oil fly ash. First, sodium chlorate solution was added to the leaching solution to oxidize vanadium ions. With adjusting pH of the solution and heating, vanadium ions(V) is hydrated and precipitated as red cake of $V_2O_5$ from the solution. After recovering vanadium, nickel is recovered as ammonium nickel sulfate with crystallization process. From this nickel salt, nickel sulfate which meets the specifications for the electroplating industry can be produced economically. More than 85% of vana-dium and nickel in the fly ash are recovered in this process.

  • PDF

Structural and optical properties of sputtered vanadium pentoxide thin films (스퍼터링으로 퇴적시킨 바나듐 산화막의 구조적, 광학적 특성)

  • Choi, Bok-Gil;Shin, Kyu-Ho;Jung, Sang-Jin;Choi, Chang-Kyu;Kim, Sung-Jeen
    • Proceedings of the KIEE Conference
    • /
    • 1998.11c
    • /
    • pp.746-748
    • /
    • 1998
  • Thin films of vanadium pentoxide ($V_{2}O_{5}$) have been deposited by r.f. magnetron sputtering from $V_{2}O_{5}$ target in gas mixture of argon and oxygen. Crystal structure, surface morphology, surface composition and optical properties of films prepared under different substrates are characterized through XRD, SEM, AES, XPS and optical absorption measurements. The films prepared below $100^{\circ}C$ are amorphous, and those prepared above $200^{\circ}C$ are polycrystalline. Thermally Induced oxidation of films into higher oxide has been observed with increasing substrate temperature. Vanadium oxide films show two optical absorption bands indicating the presence of direct and indirect transitions.

  • PDF

The fabrication of bolometric IR detector for glucose concentration detection (글루코오스 농도 측정을 위한 볼로미터 타입의 적외선 센서 제작)

  • Choi, Ju-Chan;Jung, Ho;Park, Kun-Sik;Park, Jong-Moon;Koo, Jin-Gun;Kang, Jin-Yeong;Kong, Seong-Ho
    • Journal of Sensor Science and Technology
    • /
    • v.17 no.4
    • /
    • pp.250-255
    • /
    • 2008
  • A vanadium pentoxide ($V_2O_5$)-based bolometric infrared (IR) sensor has been designed and fabricated using micro electro mechanical systems (MEMS) technology for glucose detection and its resistive characteristics has been illustrated. The proposed bolometric infrared sensor is composed of the vanadium pentoxide array that shows superior temperature coefficient of resistance (TCR) and standard silicon micromachining compatibility. In order to achieve the best performance, deposited $V_2O_5$ thin film is optimized by adequate rapid thermal annealing (RTA) process. Annealed vanadium oxide thin film has demonstrated a linear characteristic and relatively high TCR value (${-4}%/^{\circ}C$). The resistance of vanadium oxide is changed by IR intensity based on glucose concentration.