Highly sensitive detection of H2S gas at low temperature based on ZnCo2O4 microtube sensors

It is extremely necessary to detect Hydrogen sulfide (H2S) due to the hazardous nature. Thus, it is required to design a material which can detect H2S gas at low temperature. In this work, ZnCo2O4 microtubes are prepared by using absorbent cotton as template, combining immersion method in metal salt solution (Zn:Co=1:2) with calcination treatment in air. The influence of calcination temperature on the particle size and sensing property was also discussed. The diameter of particles on the ZnCo2O4 microtubes increases with increasing calcination temperature. The hollow microtubes of ZnCo2O4 materials calcined at 600 ? (ZCO-600) exhibit superb sensing performance to H2S at 90 ? with the lowest detection limit of 50 ppb. The optimum operating temperature (90 ?) was lower than the other reported ZnCo2O4 sensors. ZCO-600 sensor also shows excellent selectivity, repeatability, stability, humidity resistance and the good linear relationship in ppb and ppm level H2S. In addition, the feasible sensing mechanism of ZCO-600 to H2S is explored on the basis of XPS analysis. Thus, ZnCo2O4 as a sensing material possesses widespread application prospects for the detection of trace H2S gas.

Automated summary

In this study, ZnCo2O4 microtubes were prepared by using absorbent cotton as a template and combining immersion method with calcination treatment. The influence of calcination temperature on particle size and sensing property was investigated, and the feasible sensing mechanism of ZnCo2O4 microtubes to H2S was explored based on XPS analysis. The results showed that ZnCo2O4 microtubes exhibited excellent detection performance for H2S at low temperature.