Metal organic framework-derived Ni₄Mo/MoO₂@C composite nanospheres as the sensing materials for hydrogen sulfide detection

Hydrogen sulfide is carcinogenic, corrosive, and flammable, and pathological for most physiological processes. Nevertheless, precise and efficient H₂S detection remains challenging. Metal organic framework (MOF) derived metal alloy/oxide nanostructures have been developed recently that show enormous potential and outstanding performance for accurate H₂S detection. This paper proposes a new category of MOF derived metal alloy/oxide nanostructures prepared by wet chemical synthesis as plausible H₂S gas sensing materials. Compared with pristine sensors, NiMo-MOF sensors exhibit improved H₂S gas sensing performance attributed to synergistic effects and large surface areas. NiMo-MOF sensing material achieves the best known gas response for H₂S with negligible response to other gas molecules, including HCHO, SO₂, C₂H₅OH, CH₃OH, and NH₃. Hydrogen sulfide gas response for NiMo-MOF is 3.5 and 2.6 fold higher than bare Ni-MOF and Mo-MOF respectively. The real-time gas response shows that constructed H₂S sensor follows an adsorption-oxidation-desorption mechanism and achieved R_g/R_a value is 126 for NiMo-MOF. Thus, the proposed approach provides a mechanism to employ MOF-derived metal alloy/oxide nanostructures as active candidates for improved gas sensing towards effective H₂S detection.