Enhanced triethylamine sensing performance of superfine NiO nanoparticles decoration by two-dimensional hexagonal boron nitride

The novel two-dimensional hexagonal boron nitride (h-BN) decorated nickel oxide (NiO) heterojunction was successfully synthesized by a facile solvothermal precipitation method combining with heat treatment. SEM and TEM analysis were used to corroborate the average size (~8 nm) and overall distribution of superfine NiO nanoparticles on h-BN. XRD, FT-IR and XPS characterization confirmed the configuration of highly crystallinity and p-n heterojunction as well as the presence of surface oxygen vacancy defects. Gas sensing test results revealed that the decoration of h-BN could significantly enhanced triethylamine (TEA) sensing property of NiO. The main contribution of such remarkable results lies in NiO nanoparticles that are close to Debye length scale were embedded on vacancy defects of functionalized h-BN nanosheets, which can optimize sensitivity and selectivity by taming two-dimensional (2D) interfacial electronic effects that strongly affect nonmetal-support interaction between grain boundaries. Meanwhile, the formation of p-n Schottky nanoscale heterojunction between NiO and h-BN can significantly enlarge resistance variation and efficiently promoted the adsorbed triethylamine molecules to oxidize into NO₂, H₂O, and CO₂. Our work highlights the important role of coupling functionalized h-BN in gas sensors, which can also provide a valuable avenue in boosting the sensing performance.