A cataluminescence gas sensor for ammonium sulfide based on Fe(3)O(4)-carbon nanotubes composite.

In the present work, Fe(3)O(4)-carbon nanotubes (CNTs) composite was explored as a sensing material candidate for ammonium sulfide. Intense chemiluminescence emission can be observed during the catalytic oxidation of ammonium sulfide on the surface of Fe(3)O(4)-CNTs composite. Based on this phenomenon, a selective and sensitive gas sensor for the determination of ammonium sulfide was demonstrated. Under the optimized conditions, the linear range of cataluminescence intensity vs concentration of ammonium sulfide gas was 1.4-115 microg mL(-1) (R = 0.998) with a limit of detection (S/N = 3) of 0.05 microg mL(-1). The relative standard deviation (n = 5) for 14.3 microg mL(-1) ammonium sulfide was 1.9%. There was no response to common foreign substances, such as sulfur dioxide, toluene, aether, ethanol, acetone, hydrogen sulfide, carbon bisulfide, benzene and ammonia. The proposed sensor was successfully applied for the determination of ammonium sulfide in artificial air samples.