Reduced graphene oxide (rGO) decorated TiO2 microspheres for selective room-temperature gas sensors

Reduced graphene oxide (rGO) decorated TiO2 microspheres are prepared by using the hydrothermal method. The as-synthesized sample shows that TiO2 particles are connected by the rGO nanosheets while some TiO2 particles are found to be partly covered by rGO sheets. The rGO-decorated TiO2 based chemoresistive-type sensor shows good sensitivity and excellent selectivity to different concentrations of ammonia from 5 ppm to 50 ppm at room temperature. However, the response and recovery speeds of the sensor to ammonia are sluggish and need further optimization.