Multi-stage hierarchical self-assembled ZnIn2S4/ZnO flexible room temperature sensor for DMF sensing

It's demanding to exploit flexible room temperature (FRT) sensors due to the hazardous effects of N, N-dimethylformamide (DMF) on human tissues. In this paper, ZnIn2S4 (ZIS) is synthesised by solvothermal method, followed by the construction of ZIS/ZnO nanocomposites. The XRD and SEM confirm nanoflower-like ZIS is self-assembled from highly chemically active (110) nanosheets. The gas-sensing measurements indicate that the ZIS/ZnO FRT sensor exhibits excellent selectivity (100 ppm DMF, 78.35 %) and cycling stability, which is approximately a 39-fold improvement over ZnO sensor. In addition, the response decreases by only 5.43 % after 360 bends at 45°, and the response value of the sensor after 15 days is 72.02 %. The improved sensing characteristics can be attributed to the synergistic effect of increased specific surface area (61.09 g/cm2), linear ohmic contact and hetero-nanojunctions. The innovative material design provides a reference for improving the DMF detection efficiency of ZnO-based FRT sensor. •The response of ZnO FRT sensor is improved by 39 times.•Self-assembled structures and nano-heterojunctions of ZIS/ZnO promote carrier transfer.•Ohmic contact improves mechanical flexibility and sensing stability.