Highly selective room-temperature ammonia gas sensor based on a sheet-like NixC/ZnO heterojunction

Abstract

To address the high operating temperature of ammonia gas sensors, this study successfully constructs an Ni_xC/ZnO-1 porous, flake-like heterojunction sensing component via a hydrothermal method, achieving room-temperature ammonia detection. Under room-temperature conditions, the fabricated Ni_xC/ZnO-1 sensor demonstrates a response value of 7.20 to 100 ppm ammonia, representing 1.55- and 1.46-fold higher than those of pure Ni_xC and ZnO sensors, respectively. Particularly, the Ni_xC/ZnO-1 sensor demonstrates excellent selectivity toward 100 ppm ammonia, with the response to ammonia being at least 4.76-fold higher than those to other interfering gases. DFT simulations demonstrate that the Ni_xC-decorated ZnO heterostructures exhibit an enhanced adsorption capacity for ammonia gas, with an adsorption energy reaching −1.99956 eV. And the Ni_xC/ZnO-1 sensor also demonstrates excellent stability and repeatability, showing promising application prospects and offering feasible methodological strategies and technological routes with innovative thinking in the process of creating high-performance ammonia gas sensors under room temperature circumstance.