Metal-organic framework material derived Co3O4 coupled with graphitic carbon nitride as highly sensitive NO2 gas sensor at room temperature

ZIF-67 derived from crystalline Co3O4 coupled g-C3N4 nanosheets (NSs) was prepared and adopted for detecting ppb-level NO2 gas at room temperature (RT). As-obtained Co3O4 particles reside in the rhombohedral and porous framework structure inheriting from ZIF-67, which contact intimately with two-dimensional g-C3N4 nanosheets, leading to the formation of the p-n heterojunction. This structure has maintained the benefits from ZIF-67, such as high surface-area and greater porosity. Moreover, the introduction of n-type semiconductor g-C3N4 NSs has enhanced the local electron density of Co3O4 that can help in the fast transportation of charge carriers and resultantly increase the gas sensing properties. The optimal Co3O4/g-C3N4 presents impressive response of 17.83 to 60 ppmNO(2) gas at room temperature, with fast response time (1.06 s), quick recovery time (26.6 s), long-term stability and high selectivity. This approach offers new ideas to produce heterostructure between the metal organic frameworks-derived metal oxides with g-C3N4 NSs resultantly increases the sensitivity of metal oxides based gas-sensors, which can be used as highly potential gas sensors.

Automated summary

The research utilized a heterostructure of ZIF-67 derived Co3O4 and g-C3N4 nanosheets to detect NO2 gas, showing high sensitivity and fast response time, demonstrating the potential for high-performance gas sensor applications.