Hierarchical In2O3/rGO nanostructures with uniformly distributed In2O3 nanoparticles: microwave-assisted synthesis and improved NO-sensing performance

Uniformly distributed In2O3 nanoparticle modified reduced graphene oxide sheets (In2O3/rGO) were synthesized via a normal-pressure microwave-assisted method with an in situ growth process. In the In2O3/rGO composites, In2O3 nanoparticles with sizes ranging from 3 to 26 nm are evenly fixed on rGO surfaces. In2O3/rGO sensors exhibit high sensitivity, rapid response and recovery, and high selectivity toward 1-50 ppm NO gas at 150 degrees C. The mass ratio of indium nitrate to GO during synthesis (16-24) dramatically influences the NO-sensing properties of In2O3/rGO composites, and the 20-In2O3/rGO sensor shows the highest response at the optimal operating temperature of 150 degrees C. Compared with the In2O3 sensor, the 20-In2O3/rGO sensor presents greatly improved gas-sensing properties, including higher response, lower optimal operating temperature, and better selectivity toward NO gas. The response of the 20-In2O3/rGO sensor toward 50 ppm NO at 150 degrees C is 30.6, 6 times higher than that (5.2) of the In2O3 sensor. The enhanced NO-sensing properties of the In2O3/rGO nanocomposite could be attributed to the synergistic effect of In2O3 particles and rGO sheets.

Automated summary

Uniformly distributed In2O3 nanoparticle modified reduced graphene oxide sheets (In2O3/rGO) were synthesized via a normal-pressure microwave-assisted method with an in situ growth process. In the In2O3/rGO composites, In2O3 nanoparticles with sizes ranging from 3 to 26 nm are evenly fixed on rGO surfaces. In2O3/rGO sensors exhibit high sensitivity, rapid response and recovery, and high selectivity toward 1-50 ppm NO gas at 150 degrees C. The mass ratio of indium nitrate to GO dramatically influences the NO-sensing properties of In2O3/rGO composites, and the 20-In2O3/rGO sensor shows the highest response at the optimal operating temperature of 150 degrees C. Compared with the In2O3 sensor, the 20-In2O3/rGO sensor presents greatly improved gas-sensing properties, including higher response, lower optimal operating temperature, and better selectivity toward NO gas. The response of the 20-In2O3/rGO sensor toward 50 ppm NO at 150 degrees C is 30.6, 6 times higher than that of the In2O3 sensor. The enhanced NO-sensing properties of the In2O3/rGO nanocomposite could be attributed to the synergistic effect of In2O3 particles and rGO sheets.