Gas sensing properties of flower-like ZnO prepared by a microwave-assisted technique

Flower-like ZnO hierarchical architectures consisting of different building blocks have been successfully synthesized by a simple microwave-assisted decomposition route. The scanning electron microscopy and transmission electron microscopy results indicated that the morphologies of ZnO hierarchical architectures could be tailored by changing the category of the additives. Gas sensors based on the resulting products were fabricated and their gas sensing properties were tested for a variety of target gases. The results indicated that the sensor based on ZnO with a needle-assembled structure exhibited excellent selectivity and a higher response to NO₂ at 75 °C compared to those using the other two flower-like ZnO. The good performance observed here was likely to be the result of the high donor-related intrinsic defects.