Improved pH-Sensing Characteristics by Pt Nanoparticle-Decorated ZnO Nanostructures

Abstract

In this article, the znic oxide (ZnO) nanorods (NRs) and Pt-nanoparticles (NPs) decorated on ZnO (Pt@ZnO) NRs based on extended-gate field-effect-transistor (EG-FET) sensor were prepared and expolred through a simple hydrothermal method (HTM) and a direct current (DC) magnetron sputtering system (0 and 30 s). The results showed that all crystals preferentially grew in the c-axis direction. The ZnO and Pt@ZnO pH sensors are also called ps-0 and ps-30. The Pt sheet as reference electrode was used to test the sensitivity and linearity of buffer solutions with various pH values. It was found that both of them revealed good linearity and sensitivity, and ps-30 sample showed notably enhanced sensing characteristic. As a result, the average current and voltage sensitivities of the ps-0 samples were 15.50 μA pH−1 and 28.95 mV pH−1, and linearity curves were 0.990 and 0.978, whereas that of the ps-30 samples were 47.82 μA pH−1 and 49.83 mV pH−1 with a linearity of 0.985 and 0.994, respectively. Furthermore, the ps-30 samples have superior output response voltage, which demonstrated that the devices will be extremely useful in pH-sensing applications.