Manufacture of flexible humidity sensors with high sensitivity and fast response using MoS₂/graphene oxide composite

Humidity monitoring is very necessary for industrial production, medical and health care, environmental monitoring and household use. Resistive humidity sensor is one of common types of humidity sensors due to simple preparation and electrical readout. MoS2, a 2D material, has the great potential to be used for humidity sensing due to its high electrocatalytic activity, large specific surface area, and a wealth of surface-responsive sites. GO (graphene oxide) has excellent hydrophilic properties due to the abundance of oxygen-containing functional groups (including hydroxyl, epoxy, and carboxylic acid groups) on its surface. In addition, sensors based on pure MoS2 or pure GO are limited in either sensitivity or response and recovery time. In this work, the flexible humidity sensor based on MoS2/GO composite films was realized, featuring high responsivity (98%), fast response/recovery time (1.3/12.1s), and good stability.