Abstract
Herein, an ultrafast, sensor has been developed for trace-level detection of Ammonia (NH3) gas using hexagonal-shaped ZnO nanoparticles (NPs). The ZnO NPs were grown by low-cost eco-friendly green synthesis process and characterized by various techniques. The electron microscopic images reveal the synthesis of uniform, highly dense and hexagonal-shaped ZnO NPs. The UV–Vis spectra illustrate a band gap of 3.89eV. XRD, XPS and Raman studies explain the high-quality hexagonal wurtzite-structure of ZnO NPs showing presence of electronic/chemical states of ions. The NH3 gas sensing properties of ZnO NPs were evaluated at different concentrations. The sensor exhibited an excellent response value of 2.5 at 5 ppm NH3 wherein quick response time was 5 s and fastest recovery time was 8 s. The sensing results could be attributed to the optimum number of oxygen species and active sites which are responsible for enhanced performance of the developed ZnO NPs based sensor.
•Hexagonal shaped ZnO nanoparticles were synthesized using environmentall friendly, simple and cost-effective green synthesis process.•The fabricated sensor exhibits a trace-level detection of 0.5 (500 ppb), 1, 2, 5 and 10 ppm, at Room temperature (∼80oC) with ultra-fast response (5 sec) and recovery time (8 sec).•An excellent sensor response ∼2.5 with 5 ppm concentration has been reported.•Sensor response time is very quick (5sec) and recovery time is 8 sec at 5 ppm and low temperature.•Stable, excellent repeatability and selectivity for NH3 gas which is essentially required for mass scale production.