Highly Sensitive Room Temperature H₂S Gas Sensor Based on the Nanocomposite of MoS₂–ZnCo₂O₄

Abstract

The stacking 2D materials, such as molybdenum disulfide (MoS 2 ), are among the most promising candidates for detecting H 2 S gas. Herein, we designed a series of novel nanocomposites consisting of MoS 2 and ZnCo 2 O 4 . These materials were synthesized via a simple hydrothermal method. The microstructure and morphology of nanocomposites were studied by different characteristics such as X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy, transmission electron microscopy, high-resolution transmission electron microscopy, Brunauer–Emmett–Teller (BET), and X-ray photoelectron spectroscopy. These nanocomposites were used as gas sensors, and the highest response (6.6) toward 10 ppm of H 2 S was detected by the gas sensor of MZCO-6 (having MoS 2 contents 0.060 g) among all other tested sensors. The response value ( R a / R g ) was almost three times that of pure ZnCo 2 O 4 ( R a / R g = 2). In addition, the sensor of MZCO-6 exposed good selectivity, short response/recovery time (12/28 s), long-term stability (28 days), and a low detection limit (0.5 ppm) toward H 2 S gas at RT. The excellent performance of MZCO-6 may be attributed to some features of MoS 2 , such as stack structure, higher BET and surface area and active sites, a synergistic effect, etc. This simple fabrication sensor provides a novel idea for detecting H 2 S gas at RT.

P–N Heterojunction formation: Metal Sulfide@Metal Oxide Chemiresistor for ppb H2S Detection from Exhaled Breath and Food Spoilage at Flexible Room Temperature

“…For instance, Tan et al deposited a monolayer of MoS 2 film on a SiO 2 /Si substrate using vapor-phase deposition and then spin-coated TiO 2 on top of the film to create TiO 2 /MoS 2 films, which exhibited a 7.5 times higher response to NH 3 at room temperature compared to the original MoS 2 sensor . Sadaf et al synthesized cubic ZnCo 2 O 4 /MoS 2 nanocomposites using a hydrothermal synthesis method, achieving a 3-fold higher response to H 2 S at room temperature compared to pure MoS 2 . Zhang et al assembled three-dimensional hierarchical In 2 O 3 micro flowers from two-dimensional MoS 2 nanosheets by using a hydrothermal method, with the In 2 O 3 /MoS 2 sensor showing a 309 higher response to NO 2 at room temperature compared to pure MoS 2 .…”