A Highly Sensitive and Room Temperature CNTs/SnO 2 /CuO Sensor for H 2 S Gas Sensing Applications

Gas sensors based on tin dioxide-carbon nanotube composite films were fabricated by a simple inexpensive sol-gel spin-coating method using PEG400 as a solvent. Nanostructured copper was coated on CNTs/SnO2 film, and then copper was transformed into copper oxide at 250 °C. Resistivity of the final composite films is highly sensitive to the presence of H2S, which became easily attached or detached at room temperature. The response and recovery time of the sensor are 4 min and 10 min, and the value of sensitivity is 4.41, respectively. Meanwhile, the CNTs/SnO2/CuO sensor also has low detection limit, high selectivity toward H2S, and stable performance with different concentrations of H2S.