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 Co3O4 micro-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 Co3O4 micro-dandelions, composed of number of individual nano-needles, with substantial porosity are evidenced from the surface morphological analysis. Gas sensing results demonstrate that the Co3O4 micro-dandelions reveal higher selectivity to H2S gas at the operating temperature of 200 degrees C. Maximum response of 481% is corroborated to 200 ppm of H2S at 200 degrees C. In addition, Co3O4 micro-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. (C) 2017 Elsevier B.V. All rights reserved.