Hydrogen Sulfide Sensor Based on NiWO₄–NiO Nanoflowers Prepared From Metal–Organic Framework Derivatives

Abstract

Metal–organic framework derivative NiWO4–NiO heterojunction was fabricated for high-performance H2S sensors. X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and X-ray photoelectron spectroscopy were used to systematically characterize and analyze the NiWO4–NiO composites. The H2S gas sensitivity performances of NiO, NiWO4(5%)–NiO, and NiWO4(10%)–NiO sensors were tested under different temperatures. The NiWO4(5%)–NiO sensor yielded the best response performance to hydrogen sulfide gas at 120 °C. The metal–organic framework derivative NiWO4–NiO has a large specific surface area and porosity. Meanwhile, the heterojunction can improve the carrier migration rate. In addition, first-principles calculations further revealed the improved H2S gas-sensitizing properties of NiWO4–NiO. Therefore, the sensor has gas-sensitive properties, such as low detection limit, good reproducibility, excellent humidity resistance, and fast response/recovery time in the detection of hydrogen sulfide gas. The NiWO4(5%)–NiO-based sensor is of practical significance for hydrogen sulfide sensing.