MoS_2-xSex Nanoparticles for NO Detection at Room Temperature

Molybdenum sulfide selenide (MoS_2-xSex) solid solution nanoparticles were investigated to modify the crystal structure of molybdenum disulfide (MoS₂) for improving the nitric oxide (NO) detection performance at room temperature. The hydrothermal reaction followed by post-annealing treatments was used to engineer the structural, morphological, and electronic properties of MoS_2-xSexnanoparticles. MoS_2-xSexsamples with different selenium addition ratios (x= 0, 0.2, 1, 1.8, and 2) were prepared to understand the optimum condition for NO detection. The gradual addition of the selenium atom expanded the interlayer distance and increased the lattice parametera=bfrom 3.148(0.1) Å forx= 0 to 3.279(0.08) Å forx= 2. The chemical bonding of Mo-S expands, while Mo-Se bonding compresses in MoS_2-xSexsolid solution. The particle size also decreased after selenium addition from 500 nm forx= 0 to 80 nm forx= 2. The band gap also gradually decreased after selenium addition from 1.66 to 1.44 eV, which is related to an increase in the conductivity. The NO detection performance of MoS_2-xSexwithx= 1 showed the highest NO detection performance with a response value of around 48% due to its small particle size, high adsorption energy, high charge transferability, and good stability. MoS_2-xSexwithx= 1 detection performance was relatively stable under different humidity conditions and also was very sensitive to the NO gas molecule compared to volatile organic compound gases as well as hydrogen gas. This indicates that thex= 1 nanoparticle is very promising to be applied as a NO detection device at room temperature.