Constructing ultrathin defective Co3O4/MoS2 nanosheets based 2D/2D heterojunction toward room temperature NH3 detection

Abstract

Ultrathin 2D/2D face-to-face heterostructures have shown promising applications in gas sensing devices. Synthesis of ultrathin 2D/2D metal oxide/MoS2 based heterostructures, however, remains challenging probably due to the difficulty in preparing ultrathin 2D metal oxides. Here, ultrathin defective Co3O4/MoS2 nanosheets (NSs) with large heterointerfaces and high specific surface area are prepared via in-situ growth of MoS2 on salt-template-synthetic Co3O4 NSs. The as-obtained Co3O4/MoS2 sensor exhibits a high response value of 2.1 toward 5 ppm NH3 at room temperature, outperforming most sensors based on metal oxide/MoS2 reported hitherto. Moreover, the ultrathin defective Co3O4/MoS2 NSs sensor presents excellent selectivity and long-term stability. The excellent gas sensing performances of the Co3O4/MoS2 based sensor are attributed to the presence of rich defects and intimate interfacial electronic interaction, which ensures abundant active adsorption sites and rapid electrons transfer. Our method demonstrates a versatile integration strategy to construct 2D/2D heterostructures for innovative applications including but not limited to the gas sensing fields.