Cubic shaped hematite (α-Fe2O3) micro-structures composed of stacked nanosheets for rapid ethanol sensor application

Herein, the synthesis, characterization, and ethanol gas sensing properties of hematite iron oxide(alpha-Fe2O3) microstructures were investigated. Detailed examinations using different techniques confirmed the high-density growth and rhombohedral crystal structure of the synthesized Fe2O3 micro-structures with an average crystal size of 38.29 nm. The appearance of several Raman-active A(1g)(1), A(1g)(2), and E-g modes in Raman-scattering spectrum further revealed the formation of the hematite phase. The sensor device was fabricated using Fe2O3 micro-structures and tested for various gases such as ethanol, carbon monoxide (CO), and hydrogen (H-2). It was observed that the fabricated sensor demonstrated a high response of 13.1for 100 ppm ethanol gas concentration at a temperature of 400 degrees C. Including the response and recovery times for the fabricated sensors, the transient response for various gases was also recorded and analyzed. The fabricated sensor exhibited a rapid gas response at 400 degrees C for ethanol gas (13.1) compared to CO (1.95) and H-2 (1.71) gases for 100 ppm gas concentrations. A plausible ethanol sensing mechanism was also proposed and presented.

Automated summary

The study investigated the synthesis, characterization, and ethanol gas sensing properties of hematite iron oxide microstructures. The fabricated sensor demonstrated a high response to ethanol gas compared to CO and H-2 gases, with a proposed ethanol sensing mechanism.