J.M. Gao, J.Q. Qin, J.Y. Chang, H.Q. Liu, Z.-S. Wu,* and L. Feng*
ACS Applied Materials & Interfaces, 2020, Accepted.
The rapid development of NH3 sensor puts forward a great challenge on active materials and integrated sensing system. In this work, an ultrasensitive NH3 sensor based on 2D wormlike mesoporous polypyrrole/reduced graphene oxide (w-mPPy@rGO) heterostructures, synthesized by a universal soft template method is reported, revealing the structure-property coupling effect of w-mPPy/rGO heterostructure for sensing performance improvement, anddemonstrate great potential in the integration for self-powered sensor system. Remarkably, 2Dw-mPPy@rGO heterostructrure exhibits preferable response toward NH3 (ΔR/R0=45% for 10 ppm NH3 with detection limit of 41 ppb) than those of spherical mesoporous hybrid (s-mPPy@rGO) and nonporous hybrid (n-PPy@rGO) due to its large specific surface area (193 m2/g), which guarantees fast gas diffusion and transport of carriers. Moreover, w-mPPy@rGO heterostructures display outstanding selectivity to common volatile organic compounds (VOCs), H2S and CO, prominent anti-humidity inteference superior to most existing chemosensors, as well as superior reversibility and favorable repeatability, providing high potential for practicability. Thus, a self-powered sensor system composed of nanogenerator, lithium ion battery and w-mPPy@rGO-based sensor was fabricated to realize wireless, portable, cost-effective and light-weight NH3 monitoring. Impressively, our self-powered sensor system exhibits high response toward 5-40 mg NH4NO3, which is a common explosive to generate NH3 via alkaline hydrolysis, rendering it a highly prospective technique in NH3-based sensing field.