MoS_2–xSe_x Nanoparticles for NO Detection at Room Temperature

Abstract

Molybdenum sulfide selenide (MoS2–x Se x ) 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 MoS2–x Se x nanoparticles. MoS2–x Se x samples 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 parameter a = b from 3.148(0.1) Å for x = 0 to 3.279(0.08) Å for x = 2. The chemical bonding of Mo–S expands, while Mo–Se bonding compresses in MoS2–x Se x solid solution. The particle size also decreased after selenium addition from 500 nm for x = 0 to 80 nm for x = 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 MoS2–x Se x with x = 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. MoS2–x Se x with x = 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 the x = 1 nanoparticle is very promising to be applied as a NO detection device at room temperature.

Room-Temperature Mixed-Potential Type ppb-Level NO Sensors Based on K2Fe4O7 Electrolyte and Ni/Fe–MOF Sensing Electrodes

“…The response time to 50 ppb, 100 ppb, and 1 ppm NO was 17, 22, and 12 s, respectively, and the corresponding recovery time was 6, 11, and 55 s, respectively. This shows a better response and recovery characteristics among the room-temperature NO sensors. − …”

Ternary alloyed MoS2–xSex nanocomposites with a carrier mobility-dominated gas sensing mode: a superior room temperature gas sensing material for NO2 sensors

“…The change of particle size is considered to have an important relationship with hydrazine, which is a reducing agent and can control the reduction of MoO 4 2− to Mo 4+ . 11 The nanostructure and crystallinity of the MoS 2− x Se x -4 nanocomposites were further investigated by TEM and HRTEM techniques (Fig. 3a–d).…”

“…For all samples, significant absorption at wavelengths shorter than 750 nm can be observed. According to the Kubelka–Munk theory, where F ( R ) = (1 − R ) 2 /2 R , 11 the band gaps of the MoS 2 , MoS 2− x Se x -1, MoS 2− x Se x -2, MoS 2− x Se x -3, MoS 2− x Se x -4, and MoS 2− x Se x -5 samples were estimated to be 1.74, 1.72, 1.71, 1.63, 1.70, and 1.71 eV, respectively (Fig. 4d).…”

“…In addition, encouragingly, the crystal quality and carrier mobility could also be significantly improved by controlling the composition of alloyed TMDs. 16 In recent years, great efforts have been devoted to studying the device performance of TMD alloys such as MoS 2− x Se x , 11,17 WS 2− x Se x , 18 Mo x W 1− x Se 2 , 19 W x Mo 1− x S 2 , 20 etc. In the field of gas sensors, the alloyed TMDs have been proven to have better gas sensing performance than their binary counterparts in terms of response, charge transferability, and stability.…”

Advanced Strategies to Improve Performances of Molybdenum-Based Gas Sensors

“…Apart from the anions mentioned above, other chalcogen anions, such as selenium and tellurium, are potential doping sources for modifying the structure of MoS 2 . The advantage of using chalcogen anions as dopant is the structural similarity with MoS 2 [228]. Therefore, the MoS 2 structure is easily modified without additional impurities and secondary phase.…”