Facile synthesis of size-controlled Fe₂O₃ nanoparticle-decorated carbon nanotubes for highly sensitive H₂S detection

Hydrogen sulfide (H₂S) is one of the most plentiful toxic gases in a real-life and causes a collapse of the nervous system and a disturbance of the cellular respiration. Therefore, highly sensitive and selective H₂S gas sensor systems are becoming increasingly important in environmental monitoring and safety. In this report, we suggest the facile synthesis method of the Fe₂O₃ particles uniformly decorated on carbon nanotubes (Fe₂O₃@CNT) to detect H₂S gas using oxidative co-polymerization (pyrrole and 3-carboxylated pyrrole) and heat treatment. The as prepared Fe₂O₃@CNT-based sensor electrode is highly sensitive (as low as 1 ppm), selective and stable to H₂S gas at 25 °C, which shows promise for operating in medical diagnosis and environment monitoring. Excellent performance of the Fe₂O₃@CNT is due to the unique morphology of the nanocomposites made from uniformly dispersed Fe₂O₃ nanoparticles on the carbon surface without aggregation.