Ag@SnO 2 /g‐C 3 N 4 Ternary Nanocomposite as an Efficient Acetone Vapors Sensor

Abstract Ternary nanocomposite of Ag modified SnO 2 (Ag@SnO 2 ) nanoparticles and graphitic carbon nitride (g‐C 3 N 4 ) nanosheets (Ag@SnO 2 /g‐C 3 N 4 ) have been successfully synthesized using a facile hydrothermal method. The synthesized nanostructures were subjected to various characterization techniques to investigate their structural, morphological, optical, and chemical properties. The XRD results confirm the crystalline nature and rutile phase of the synthesized SnO 2 ‐based nanostructures, while SEM and TEM revealed morphological characteristics of Ag@SnO 2 and high dispersion of Ag@SnO 2 nanoparticles on the surface of g‐C 3 N 4 nanosheets. The gas sensing performance of the samples (Ag@SnO 2 and Ag@SnO 2 /g‐C 3 N 4 ) was evaluated towards 1 µL of acetone vapors in 2L sensing chamber at various operating temperatures. Ag@SnO 2 /g‐C 3 N 4 based resistive gas sensor exhibited admirable sensitivity at (28%), which is ∼ 4 times higher than that of Ag@SnO 2 based sensor, and good repeatability towards acetone vapors at an operating temperature of 100 °C. The enhanced sensing results of Ag@SnO 2 /g‐C 3 N 4 ‐based sensors at relatively low working temperatures are attributed to its high surface area (104.6 m 2 /g), reduced energy band gap from 2.8 eV to 2.4 eV, and strong interaction between Ag@SnO 2 nanoparticles and 2D g‐C 3 N 4 nanosheets. Furthermore, a suitable sensing mechanism has been presented to explain the enhanced gas sensing properties of Ag@SnO 2 and Ag@SnO 2 /g‐C 3 N 4 based resistive gas sensor.