J.Q. Qin, J.M. Gao, X.Y. Shi, J.Y. Chang, Y.F. Dong, S.H. Zheng, X. Wang, L. Feng,* and Z-S Wu*

Advanced Functional Materials, 2020, 30, 1909756.

DOI: 10.1002/adfm.201909756 [PDF]

Planar integrated systems of micro-supercapacitor (MSC) and sensor are of profound importance for 3C electronics, but usually appear poor compatibility due to the complex connections of device units with multiple mono-functional materials. Herein, a two-dimensional hierarchical ordered dual-mesoporous polypyrrole/graphene (DM-PG) nanosheet is developed as bi-functional active materials for a novel prototype planar integrated system of MSC and NH3 sensor. Owing to effective coupling of conductive graphene and high-sensitive pseudocapacitive polypyrrole, well-defined dual-mesopores of ~7 and ~18 nm, hierarchical mesoporous network, and large surface area of 112 m2 g-1, the resultant DM-PG nanosheets exhibit extraordinary sensing response to NH3 as low as 200 ppb, exceptional selectivity towards NH3 that is much higher than other volatile organic compounds, and outstanding capacitance of 376 F g-1 at 1 mV s-1 for supercapacitors, simultaneously surpassing single-mesoporous and non-mesoporous counterparts. Importantly, the bi-functional DM-PG-based MSC-sensor integrated system represents rapid and stable response exposed to 10~40 ppm of NH3 only after charging for 100 s, remarkable sensitivity of NH3 detection that is closed to DM-PG based MSC-free sensor, impressive flexibility with ~82% of initial response value even at 180°, and enhanced overall compatibility, thereby holding great promise for ultrathin, miniaturized, body-attachable, and portable detection of NH3.