Size-controlled synthesis of ZnO tetrapods using atmospheric pressure microwave plasma jets and application in NH3 gas detection

초록

Research on gas-detection sensors using metal oxides has gained significant attention due to their potential applications in environmental monitoring and safety. ZnO tetrapods, owing to their distinctive morphology, offer enhanced gas sensing properties. In this study, ZnO tetrapods were synthesized using an atmospheric pressure microwave plasma (APMP) system with 10 mu m Zn powder as a precursor. This method enables rapid, large-scale production without the need for high-vacuum or high-temperature environments. The synthesized ZnO tetrapods exhibited particle sizes ranging from 100 to 700 nm, depending on applied plasma power and collection location. The ZnO tetrapods were subsequently spray-coated onto SiO2/Si substrates with Au electrodes to fabricate gas sensors. The NH3 sensing performance was evaluated, revealing that reducing the particle size from 700 to 100 nm increased the sensor response, defined as Ra/Rg (where Ra and Rg represent the electrical resistance in dry air and NH3 gas, respectively), by approximately 24.4 %, from 1.09 to 1.31. These results demonstrate that ZnO tetrapods with controlled morphology can serve as highly efficient gas-sensing materials.

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