Light-assisted recovery for a highly-sensitive NO 2 sensor based on RGO-CeO 2 hybrids

•Intrinsic properties of CeO2 have been fully considered to fabricate an excellent RGO-CeO2 (NH3·H2O) NO2 sensor.•∼3 nm CeO2 nanocrystals anchoring on RGO layer formed a heterostructure which greatly enhanced the sensing properties.•∼51 times enhancement of sensitivity and enhanced recovery speed (258 s vs several hours) of the sensor are realized. High sensing performance (4.59–10 ppm NO2), repeatability and selectivity of the sensor presented.•Reasonable mechanism has been proposed to explain the enhancement of sensing performance.