Resources Recycling (자원리싸이클링)

The Korean Institute of Resources Recycling (한국자원리싸이클링학회)
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Introduction to Electrochemical Quartz Crystal Microbalance Technique for Leaching Study of Metals

금속 침출연구를 위한 전기화학적 미소수정진동자저울 기술 소개

  • Kim, Min-seuk (Mineral Resource Research Division, Korea Institute of Geoscience and Mineral Resources) ;
  • Chung, Kyeong Woo (Mineral Resource Research Division, Korea Institute of Geoscience and Mineral Resources) ;
  • Lee, Jae-chun (Mineral Resource Research Division, Korea Institute of Geoscience and Mineral Resources)
  • 김민석 (한국지질자원연구원 광물자원연구본부 자원회수연구센터) ;
  • 정경우 (한국지질자원연구원 광물자원연구본부 자원회수연구센터) ;
  • 이재천 (한국지질자원연구원 광물자원연구본부 자원회수연구센터)
  • Received : 2019.10.10
  • Accepted : 2019.12.04
  • Published : 2020.02.28
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Abstract

Electrochemical Quartz Crystal microbalance is a tool that is capable of measuring nanogram-scale mass change on electrode surface. When applying alternating voltage to the quartz crystal with metal electrode formed on both sides, a resonant frequency by inverse piezoelectric effect depends on its thickness. The resonant frequency changes sensitively by mass change on its electrode surface; frequency increase with metal dissolution and decrease with metal deposition on the electrode surface. The relationship between resonant frequency and mass change is shown by Sauerbrey equation so that the mass change during metal dissolution can be measured in real time. Especially, it is effective in the case of reaction mechanism and rate studies accompanied by precipitation, volatilization, compound formation, etc. resulting in difficulties on ex-situ AA or ICP analysis. However, it should be carefully considered during EQCM experiments that temperature, viscosity, and hydraulic pressure of solution, and stress and surface roughness can affect on the resonant frequency. Application of EQCM was shown as a case study on leaching of platinum using aqueous chlorine for obtaining activation energy. A platinum electrode of quartz crystal oscillator with 1000 Å thickness exposed to solution was used as leaching sample. Electrogenerated chlorine as oxidant was purged and its concentration was controlled in hydrochloric acid solution. From the experimental results, platinum dissolution by chlorine is chemical reaction control with activation energy of 83.5 kJ/mol.

전기화학적 미소수정진동자저울은 전극표면에서 발생하는 나노그램 수준의 질량변화를 실시간 측정할 수 있는 장비이다. 역압전효과를 가진 수정진동자 양면에 형성된 금속전극에 교대로 전계를 가하면 진동자의 두께에 따라 특정 공진주파수를 나타낸다. 공진주파수는 전극표면에서 발생하는 질량변화에 반응하며, 전극표면의 금속이 용해될 때는 증가하고 석출될 때는 반대로 감소한다. 공진주파수와 질량변화의 상관관계는 Sauerbrey 식으로 나타내고 이를 이용하여 금속의 침출반응때 발생하는 질량변화를 실시간으로 측정할 수 있다. 특히 용해 후 침출액에서 침전, 휘발, 기타 화합물 형성 등 부반응으로 실험 후 발광분광분석이나 원자흡광분석 등이 용이하지 않은 금속의 침출 반응기구 및 속도 연구에 매우 효과적이다. 그러나 수정진동자의 공진주파수는 질량변화 외에도 용액의 점도, 수압, 온도, 스트레스, 그리고 표면거칠기 등에도 영향을 받으므로 실험 시 이들 영향에 대한 고려가 필요하다. 전기화학적 미소수정진동자저울의 응용 예로서 염소를 이용한 백금의 침출 시 용해속도를 실시간 측정하고 이로부터 활성화에너지를 구하는 일련의 과정을 소개하였다. 침출에 사용된 백금시료는 수정진동자 양면에 형성된 1000 Å두께의 백금전극 중 침출액에 노출된 한쪽 면을 활용하였으며, 전해생성된 염소를 염산 침출액에 주입하여 침출 시 용존 염소농도를 조절하였다. 실험결과로부터 염소에 의한 백금의 용해반응은 활성화에너지가 83.5 kJ/mol로 화학반응율속임을 확인하였다.

Keywords

References

  1. King, W.H., 1971 : Vacuum Microbalance Techniques, pp.183, Plenum, New York.
  2. Nomura, T., Okuhara, M., 1982 : Frequency shifts of piezoelectric quartz crystals immersed in organic liquids, Anal. Chim. Acta, 142, pp.281-284. https://doi.org/10.1016/S0003-2670(01)95290-0
  3. Kanazawa, K.K., Gordon II, J.G., 1985 : Frequency of a quartz microbalance in contact with liquid., Anal. Chem., 57, pp.1770-1771. https://doi.org/10.1021/ac00285a062
  4. Bruckenstein, S., Shay, M., 1985 : Experimental aspects of use of the quartz crystal microbalance in solution. Electrochim. Acta, 30, pp.1295-1300. https://doi.org/10.1016/0013-4686(85)85005-2
  5. Czanderna, A.W., Lu, C., 1984 : Introduction, history, and overview of applications of piezoelectric quartz crystal microbalances, Application of piezoelectric quartz crystal microbalances, pp.2-4, Elservier, New York.
  6. Lu, C., 1984 : Theory and practice of the quartz crystal microbalance, Application of piezoelectric quartz crystal microbalances, pp.20-23, Elservier, New York.
  7. Sauerbrey, G., 1959 : Verwendung von Schwingquarzen zur Wagung diinner Schichten und zur Mikrowagung, Zeitschrift fiir Physik, 55, pp.206-222. https://doi.org/10.1007/BF01337937
  8. Srivastava, A.K., Sakthivel, P., 2001 : Quartz-crystal microbalance study for characterizing atomic oxygen in plasma ash tools, J. Vac. Sci. Technol. A, 19, pp.97-100. https://doi.org/10.1116/1.1335681
  9. Deakin, M.R. Buttry, D.A., 1989 : Electrochemical Applications of the Quartz Crystal Microbalance, Anal. Chem., 61, pp.1147A-1154A. https://doi.org/10.1021/ac00195a001
  10. Arnau, A., 2008 : A Review of Interface Electronic Systems for AT-cut Quartz Crystal Microbalance Applications in Liquids, Sensors, 8, pp.370-411 https://doi.org/10.3390/s8010370
  11. Le T., et al., 2019 : Understanding the energy storage mechanisms of poly(3,4-ethylenedioxythiophene)-coated silicon nanowires by electrochemical quartz crystal microbalance, Mater. Lett., 240, pp.59-61. https://doi.org/10.1016/j.matlet.2018.12.119
  12. Lukaszewski, M., Czerwinski, A., 2006 : Dissolution of noble metals and their alloys studied by electrochemical quartz crystal microbalance, J. Electroanal. Cheme., 589, pp.38-45. https://doi.org/10.1016/j.jelechem.2006.01.007
  13. Fanta, A.B.S. et al., 2017 : Influence of Ti and Cr Adhesion Layers on Ultrathin Au Films, ACS Appl. Mater. Interfaces, 9, pp.37374-37385. https://doi.org/10.1021/acsami.7b10136
  14. Kim, M.S., Kim, K.B., 1997 : Electrochemical Quartz Crystal Microbalance, J. Corros. Sci. of Korea, 26, pp.312-320.
  15. Vatankhah, G., et al., 2003 : Dependence of the reliability of electrochemical quartz-crystal nanobalance mass responses on the calibration constant, $C_f$ : analysis of three procedures for its determination, Electrochim. Acta, 48, pp.1613-1622. https://doi.org/10.1016/S0013-4686(03)00083-5
  16. Bruckenstein, S., Shay, M., 1985 : Experimental aspects of use of the quartz crystal microbalance in solution, Electrochim. Acta, 30, pp.1295-1300. https://doi.org/10.1016/0013-4686(85)85005-2
  17. Urbakh, M., Leonid Daikhin, L., 1994 : Roughness effect on the frequency of a quartz-crystal resonator in contact with a liquid, Phys. Rev. B, 49, pp.4866-4870. https://doi.org/10.1103/PhysRevB.49.4866
  18. Rahtu, A., Mikko Ritala, M., 2002 : Compensation of temperature effects in quartz crystal microbalance measurements, Appl. Phys. Lett. 80, pp.521-523. https://doi.org/10.1063/1.1433904
  19. Muramatsu, H., Tamiya, E., and Karube, I., 1988 : Computation of equivalent circuit parameters of quartz crystals in contact with liquids and study of liquid properties, Anal. Chem., 60, pp.2142-2146. https://doi.org/10.1021/ac00170a032
  20. Rodahl, M., Kasemo, B., 1996 : Frequency and dissipationfactor responses to localized liquid deposits on a QCM electrode, Sensor. Actuat. B, 37, pp.111-116. https://doi.org/10.1016/S0925-4005(97)80077-9
  21. Bai, Q., Huang, X., 2016 : Using Quartz Crystal Microbalance for Field Measurement of Liquid Viscosities, 2016, J. Sensors, pp.1-7.
  22. Ullevlg, D.M., Evans, J.F., and Albrecht, M.G., 1982 : Effects of Stressed Materials on the Radial Sensitivity Function of a Quartz Crystal Microbalance, Anal. Chem., 54, pp.2341-2343. https://doi.org/10.1021/ac00250a045
  23. EerNisse, E.P., 1973 : Extension of the double resonator technique, J. Appl. Phys., 44, pp.4482-4485. https://doi.org/10.1063/1.1661986
  24. EerNisse, E.P., 1984 : Stress effects in quartz crystal microbalances, Application of piezoelectric quartz crystal microbalances, pp.125-149, Elservier, New York.
  25. Aieta, E.M., Roberts, P.V., and Hernandez, M., 1984 : Determination of chlorine dioxide, chlorine, chlorite, and chlorate in water. Res Technol., pp.64-70.