One-pot fabrication of g-C3N4-NiO@SnO2 composites for high-performance acetone vapor detection

A facile one-pot calcination method has been proposed to synthesize melamine derived g-C3N4 sheet incorporated NiO&SnO2 (g-C3N4-NiO@SnO2) composites and utilizing for highly sensitive detection of acetone vapor. SnO2 nanoparticles of size around 10 nm anchor on the g-C3N4 sheet, and the octahedral variable-sized NiO is embedded in the g-C3N4 sheet, together to build a multiple heterostructures. This unique structure provides a significant advantage by offering an abundance of active sites and plays a crucial role in accelerating the transport of carriers, which greatly improve the sensing performance. The as-prepared g-C3N4-NiO@SnO2(25.0%) sensor shows high response (Ra/Rg) of 150.3 toward 100 ppm acetone at 340 ℃ and exhibits limit of detection (LOD) of 125 ppb with good repeatability, selectivity and linearity. Meanwhile, the obtained sensor performs fast response/recovery speed of ~5 s/4 s and good long-term stability. The sensing mechanism has been discussed in detail and the construction of 3D multiple heterostructures is recognized as main factor for the enhanced acetone sensing performance. This proposal provides an important reference for the rapid and large-scale preparation of composite metal oxide gas sensing material.