THE DETECTION OF H-2 GAS BY METAL PHTHALOCYANINE-BASED GAS SENSORS

H-2 gas sensors, made of lead phthalocyanine (PbPc) mixed with RuO2 and Pd, have been prepared. Their sensitivities and responses to H-2 gas have been investigated. An 8000 ppm concentration of H-2 gas changes the resistivity of PbPc doped with 10 wt.% RuO2 and 2 wt.% Pd, making it 10 times lower than that in air at 120-degrees-C. Furthermore, the sensors exhibit high responsivities to H-2 gas at 120-degrees-C. It is also found that PbPc-based sensors behave as n-type Semiconductors to H-2 gas on doping with RuO2 and Pd. even though pure PbPc is a p-type semiconductor. The response mechanism of PbPc-based sensors to H-2 gas (n-type or p-type semiconductor behaviour) is also discussed.