Ordered porous RGO/SnO2 thin films for ultrasensitive humidity detection

Abstract

In this work, ordered porous thin films of reduced graphene oxide and tin oxide (rGO/SnO₂) were synthesized by a polystyrene sphere monolayer colloidal crystal template method, and their gas-sensing properties were systematically studied. The formed amorphous SnO₂ and partially reduced graphene oxide were analyzed using several complementary material characterization techniques. The results show that the incorporation of rGO significantly improved the humidity sensitivity and the electrical conductivity of the sensor relative to the pristine SnO₂ thin film. Fast response time and excellent selectivity towards humidity were also achieved for the rGO/SnO₂ composite film. The long-term stability of the rGO/SnO₂ sensor was confirmed by comparing its performance to a commercial humidity sensor. The enhanced sensor performance is attributed to the synergistic effects of the incorporation of rGO and the ordered porous structure of the composite film.