Long-term reliable wireless H2 gas sensor via repeatable thermal refreshing of palladium nanowire
Ki-Hoon Kim, Min‐Seung Jo, Sungho Kim, Bo-Kyeong Kim, Joonhee Kang, Jun‐Bo Yoon, Min‐Ho Seo
Abstract
The increasing significance of hydrogen (H2) gas as a clean energy source has prompted the development of high-performance H2 gas sensors. Palladium (Pd)-based sensors, with their advantages of selectivity, scalability, and cost-effectiveness, have shown promise in this regard. However, the long-term stability and reliability of Pd-based sensors remain a challenge. This study not only identifies the exact cause for performance degradation in palladium (Pd) nanowire H2 sensors, but also implements and optimizes a cost-effective recovery method. The results from density functional theory (DFT) calculations and material analysis confirm the presence of C = O bonds, indicating performance degradation due to carbon dioxide (CO2) accumulation on the Pd surface. Based on the molecular behavior calculation in high temperatures, we optimized the thermal treatment method of 200 °C for 10 minutes to remove the C = O contaminants, resulting in nearly 100% recovery of the sensor’s initial performance even after 2 months of contamination. Retaining sensor performance with long-term use is highly challenging. Here, the authors refined the thermal recovery method in Pd nanowire H2 sensors, effectively removing C = O surface contaminants to ensure long-term stability.