Solution-processed rapid synthesis strategy of Co₃O₄ for the sensitive and selective detection of H₂S

A simple, rapid, and inexpensive solution-processed synthesis strategy for mass production of cobalt oxide (Co₃O₄) micro-dandelions has been applied and reported. As-synthesized Co₃O₄micro-dandelions are initially characterized for their structure and morphology confirmations and subsequently utilized for the fabrication of low-cost high-performance hydrogen sulfide (H₂S) gas sensor. Structural analysis is in accordance with the formation of polycrystalline face- centered cubic Co₃O₄. Several aggregated Co₃O₄micro-dandelions, composed of number of individual nano-needles, with substantial porosity are evidenced from the surface morphological analysis. Gas sensing results demonstrate that the Co₃O₄micro-dandelions reveal higher selectivity to H₂S gas at the operating temperature of 200 °C. Maximum response of 481% is corroborated to 200 ppm of H₂S at 200 °C. In addition, Co₃O₄micro-dandelions detect H₂S at levels as low as 5 ppm with enhanced response of 68%, rapid response time of 5 s and recovery time of 30 s, demonstrating its potential as a sensing material in the development of H₂S related sensors.