Hierarchical Ordered Dual-Mesoporous Polypyrrole/Graphene Nanosheets as Bi-Functional Active Materials for High-Performance Planar Integrated System of Micro-Supercapacitor and Gas Sensor

Planar integrated systems of micro-supercapacitors (MSCs) and sensors are of profound importance for 3C electronics, but usually appear poor in compatibility due to the complex connections of device units with multiple mono-functional materials. Herein, 2D hierarchical ordered dual-mesoporous polypyrrole/graphene (DM-PG) nanosheets are 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 approximate to 7 and approximate to 18 nm, hierarchical mesoporous network, and large surface area of 112 m(2) g(-1), the resultant DM-PG nanosheets exhibit extraordinary sensing response to NH3 as low as 200 ppb, exceptional selectivity toward 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 after only charging for 100 s, remarkable sensitivity of NH3 detection that is close to DM-PG-based MSC-free sensor, impressive flexibility with approximate to 82% of initial response value even at 180 degrees, and enhanced overall compatibility, thereby holding great promise for ultrathin, miniaturized, body-attachable, and portable detection of NH3.