Dissolved hydrogen gas analysis in transformer oil using Pd catalyst decorated on ZnO nanorod array

A resistivity-type hydrogen (H2) sensor based on palladium (Pd)-decorated zinc oxide (ZnO) nanorod (NR) array has been developed to detect the dissolved H2 gas in the transformer oil. The Pd catalyst decorated on the ZnO NRs not only enhanced the H2 sensing properties at room temperature, but also played an important role to protect the ZnO NRs in liquid environment, which resulted long-term stability of the fabricated device. The H2 sensor had a temperature coefficient of resistance (TCR) of 68.45 × 10−4/°C, and showed the potential to detect H2 gas dissolved in transformer oil with a detection range of 5-1000 ppm. The sensor showed high response towards H2 within 5-100 ppm gas concentrations, which is critical to develop a H2 sensor for transformer oil. The kinetic H2 absorption/desorption in sensors was also investigated at different oil temperatures. Moreover, the fabricated sensor achieved high response, good repeatability, and long-term stability in oil, making it a promising candidate for transformer oil applications.