초록

본 연구에서는 Cu가 코팅된 나노 SnO2:Cu 센서를 기반으로 한 CH4, CH3CH2CH3 gas의 감응 특성에 대대 연구하였다. 나노 SnO2 분말은 SnCl2·2H2O, hydrazine, NaOH를 혼합하여 제조하였고, 열처리를 통해 나노 SnO2 분말을 얻었다. XRD 결과, SnO2의 (110), (101), (211)면의 주피크가 일치하여 나타났다. Cu를 8 wt% 첨가한 나노 SnO2:Cu의 경우 입자 크기는 약 50 nm로 나타났다. SEM 결과, SnO2 입자들은 많은 기공을 포함하고 있었다. 나노 SnO2:Cu 가스센의 감도는 공기중에서의 저항과 가스를 흘려준 후 저항의 비로 나타내었고, CH4 gas and CH3CH2CH3 gas 5 ppm에 대한 감응 특성을 실온에서 측정하였다. CH4 gas and CH3CH2CH3 gas 두 가스 모두에서 Cu가 코팅된 나노 SnO2:Cu의 경우 감도가 향상되었다. 나노 SnO2:Cu 가스센서의 CH4 gas and CH3CH2CH3 gas에 대한 반응 시간은 약 18∼20초, 회복시간은 약 13∼15초로 나타났다.

Abstract

The effect of Cu coating on the sensing properties of nano SnO2:Cu based sensors for the CH4, CH3CH2CH3 gas was studied. This work was focussed on investigating the change of sensitivity of nano SnO2:Cu based sensors for CH4, CH3CH2CH3 gas by Cu coating. Nano sized SnO2 powders were prepared by solution reduction method using stannous chloride(SnCl2·2H2O), hydrazine(N2H2) and NaOH and subsequent heat treatment. XRD patterns showed that nano SnO2 powders with rutile structure were grown with (110), (101), (211) dominant peak. The particle size of nano SnO2:Cu powders at 8 wt% Cu was about 50 nm. SnO2 particles were found to contain many pores, according to SEM analysis. The sensitivity of nano SnO2:Cu based sensors was measured for 5 ppm CH4 gas and CH3CH2CH3 gas at room temperature by comparing the resistance in air with that in target gases. The sensitivity for both CH4 and CH3CH2CH3 gases was improved by Cu coating on the nano SnO2 surface. The response time and recovery time of the SnO2:Cu gas sensors for the CH4 and CH3CH2CH3 gases were 18∼20 seconds, and 13∼15 seconds, respectively.

• Keywords: Nano, Hydrazine, SnO2:Cu, CH4, CH3CH2CH3