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

Abstract

(1 of 9)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 NH 3 sensor. Owing to effective coupling of conductive graphene and highsensitive pseudocapacitive polypyrrole, well-defined dual-mesopores of ≈7 and ≈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 NH 3 as low as 200 ppb, exceptional selectivity toward NH 3 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 NH 3 after only charging for 100 s, remarkable sensitivity of NH 3 detection that is close 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 NH 3 .

NiCo2O4/RGO Hybrid Nanostructures on Surface-Modified Ni Core for Flexible Wire-Shaped Supercapacitor

“…Such macropores resulting from electrode roughness ensure the wetting of the electrode surface and fast ion diffusion at higher applied current, therefore ensuring a high rate performance [ 41 ]. Further, the evident micropores are highly significant for enhancing ion diffusion kinetics that improves the capacitance behavior of supercapacitors while contributing to the lower equivalent resistance [ 42 ]. Moreover, the total surface area and total percentage porosity of Ni 00 /NCO/RGO, Ni 10 /NCO/RGO, Ni 20 /NCO/RGO, and Ni 30 /NCO/RGO electrodes varies at ~17, ~92, ~16, ~16 m 2 /g and ~79, ~98, ~71, and ~70%, respectively.…”

Recent developments of advanced micro-supercapacitors: design, fabrication and applications

“…In this context, it is highly desirable to construct multifunctional materials that can work for all the devices involved. For instance, Qin et al 131 reported the synthesis of 2D hierarchically ordered dual-mesoporous Ppy/ graphene (DM-PG) nanosheets as bi-functional active materials for both MSC and NH 3 sensor (Fig. 6c).…”

Laser fabrication of functional micro-supercapacitors

“…According to the laser technology in processing diversified micro-electrodes, the developed MSCs are easily integrated with other energy-related devices in widespread fields, showing great potential in practical intelligent application [215,231]. At present, laser-fabricated MSCs have been widely used in solar cells, photodetectors, sensors and generators [232].…”