Synthesis of nanograiny SnO2 films on laser-patterned graphene/ceramic substrates for low-temperature ethanol gas sensors

This study proposed a facile low-cost sol-gel method to synthesize nanograiny SnO2 films on laser-patterned graphene/ceramic substrates for ethanol gas detection at a low working temperature. A high pulsed fiber laser processing system was used to pattern interdigitated and triangular electrodes on the sensing and heating layers, respectively, of the graphene/ceramic substrates. The synthesized SnO2 had nanograiny structures and irregular micro-/nano-holes on the film surface. Thus, the synthesized SnO2 films had increased surface area and volume ratio. In addition, graphene-based electrode structures were patterned using the following optimum laser machining parameters: pulse repetition frequency of 750 kHz, pulse width of 4 ns, scan speed of 50 mm/s, scanning pitch of 0.01 mm, areal fluence of 982 J/cm2, and one patterning pass. For ethanol gas detection, the nanograiny SnO2 sensors showed the best response of 3.18% for an ethanol gas concentration of 1000 ppm at a working temperature of 84 degrees C. Furthermore, the response and recovery times were calculated to be approximately 13 s and 4 s, respectively. The developed gas sensors exhibited an excellent response and short response and recovery times at low working temperatures.

Automated summary

This study developed a low-cost sol-gel method to synthesize nanograiny SnO2 films on laser-patterned graphene/ceramic substrates for ethanol gas detection at low temperatures. The synthesized SnO2 films had increased surface area and volume ratio due to their nanograiny structures and irregular micro-/nano-holes. The nanograiny SnO2 sensors showed a high response of 3.18% to 1000 ppm ethanol gas at a low working temperature of 84 degrees C, with response and recovery times of approximately 13 s and 4 s, respectively.