High ammonia sensitive ability of novel Cu12Sb4S13 quantum dots@reduced graphene oxide nanosheet composites at room temperature

In the work, rGO nanosheet is synthesized using the typical Hummer’s method, then Cu 12 Sb 4 S 13 quantum dots@rGO composites are prepared by solvent thermal method, and Cu 12 Sb 4 S 13 quantum dots with the average size of 5 nm are densely distributed on the surface of rGO sheet. NH 3 gas response of Cu 12 Sb 4 S 13 quantum dots@rGO nanosheet composites at room temperature of 25 °C is enhanced compared with the pure Cu 12 Sb 4 S 13 quantum dots and rGO nanosheet, and the composites possess an excellent stability during the humidity range of 45%–80% with a low detection limit of 1 ppm, which is related with the intrinsic hydrophobicity characteristic of Cu 12 Sb 4 S 13 quantum dots. It also proves that Cu 12 Sb 4 S 13 quantum dots@rGO nanosheet composites have a quite high selectivity towards ammonia compared with ethanol, methanol, acetone, toluene, hydrogen sulfide and nitrogen dioxide at room temperature. The gas sensing mechanism of the composites is discussed primarily.