Duo Zhang,Ying-Nan Dou,Rui Gao,Xian-Fa Zhang,Hui Zhao,Xiao-Li Cheng,Shan Gao,Ying-Ming Xu,Li-Hua Huo
Rapid, highly sensitive detection of mustard gas is a critical requirement in public safety and national defense. However, achieving highly sensitive, ppb-level detection of mustard gas under low-power conditions remains a significant challenge. Focusing on the typical blister agent simulant 2-chloroethyl ethyl sulfide (2-CEES), a solvothermal method was employed combined with controlled thermal treatment to fabricate an ultrathin porous NiFe 2 O 4 /NiO nanosheets heterostructure sensor derived from an Fe-Ni-MOF in-situ grown on a ceramic tube in this study. This material possesses uniformly distributed intimate heterogeneous interface, a high specific surface area (95.8 m 2 ·g −1 ), and abundant surface active sites, thereby significantly enhancing its adsorption and catalytic oxidation capability toward 2-CEES. At a low operating temperature of 130 °C, the sensor demonstrates a high response of 41.5 toward 10 ppm 2-CEES, a rapid recovery capability of only 84 s, and a low detection limit of 20 ppb, along with excellent selectivity, humidity resistance, reproducibility, and long-term stability. Through systematic characterization including XPS, in-situ DRIFTS, TPD, and DFT calculations, the multi-step catalytic oxidation pathway of 2-CEES on the composite surface is elucidated, along with the mechanism by which the heterostructure enhances gas-sensing performance via band structure modulation, interfacial charge transfer, and the built-in electric field. This study offers both new materials and novel insights for the development of low-power, highly sensitive sensors for trace detection of chemical warfare agents.
Developing an efficient and low-cost electrocatalyst is important in energy conversion and storage, while it is challenging especially in the oxygen evolution reaction (OER) owing to the sluggish kinetic process. Hofmann-type metal–organic frameworks (MOFs) are layer-structured materials, and if they are synthesized in the form of regular-shaped and slim nanosheets, a higher density of exposed active sites and easier electron and mass transport will be expected. In the current study, we prepared such a type of Hofmann MOFs plus Ni site tuning for the OER. The characterizations verified the successful material synthesis and characteristics. Density functional theory (DFT) simulations proved that the Ni site modified by Fe atom is more efficient for the critical OH* as well as O* intermediate formation. Taking advantage of the designed unique structure configuration, the as-obtained Fe–Ni Hofmann-type MOF showed the OER activity with an overpotential of 290 mV at the current density of 10 mA cm–2 and a Tafel slope of 44 mV dec–1, the very best performance plus outstanding durability among the Hofmann-type MOFs for the OER known to date.
危险品化学品经营许可证（带存储）