Inducement of nanoscale Cu–BTC on nanocomposite of PPy–rGO and its performance in ammonia sensing

In this study, polypyrrole-nanofiber-coated reduced graphene oxide (PPy–rGO) was decorated with nanoparticles of Cu–BTC [Cu3(BTC)2(H2O)3, where BTC is short for benzene-1,3,5-tricarboxylate], a typical metal–organic framework, via a hydrothermal process combined with in situ chemical polymerization. The Cu–BTC nanoparticles enabled gas capture because of their large surface area and high affinity for gases. PPy–rGO induced the formation of nanometer-sized Cu–BTC particles and provided a good platform for gas sensing because of the resulting decorated composite's good electrical properties. The Cu–BTC/PPy–rGO nanocomposite exhibited good electrical-resistance response to NH3 at room temperature. Compared to the PPy–rGO thin film, the Cu–BTC/PPy–rGO thin film showed enhanced NH3-sensing properties in the form of higher sensitivity and much faster response under the same conditions. The selectivity and stability of the NH3 sensor based on the Cu–BTC/PPy–rGO nanocomposite were also investigated.