Highly Durable Chemoresistive Micropatterned PdAu Hydrogen Sensors: Performance and Mechanism

• Published in: ACS sensors
• Main Authors: Kim, Yeong Jae, Lee, Seonyong, Choi, Sungkyun, Eom, Tae Hoon, Cho, Sung Hwan, Park, Sohyeon, Park, Sung Hyuk, Kim, Jae Young, Kim, Jaehyun, Nam, Gi Baek, Ryu, Jung-El, Park, Seon Ju, Lee, Soo Min, Lee, Gun-Do, Kim, Jihyun, Jang, Ho Won
• Format: Journal Article
• Language: English
• Published: United States 24.09.2024
• Subjects: DFT calculation; alloy; durability; palladium; hydrogen sensor; CI-NEB; chemoresistive
• ISSN: 2379-3694; 2379-3694
• DOI: 10.1021/acssensors.4c01599

Hydrogen (H ) is a promising alternative energy source for Net-zero, but the risk of explosion requires accurate and rapid detection systems. As the use of H energy expands, sensors require high performance in a variety of properties. Palladium (Pd) is an attractive material for H detection due to its high H affinity and catalytic properties. However, poor stability caused by volume changes and reliability due to environmental sensitivity remain obstacles. This study proposes a micropatterned thin film of PdAu with optimized composition (Pd Au ) as a chemoresistive sensor to overcome these issues. At room temperature, the sensor has a wide detection range of 0.0002% to 5% and a fast response time of 9.5 s. Significantly, the sensor exhibits excellent durability for repeated operation (>35 h) in 5% H and resistance to humidity and carbon monoxide. We also report a negative resistivity change in PdAu, which is opposite to that of Pd. Density functional theory (DFT) calculations were performed to investigate the resistance change. DFT analysis revealed that H penetrates specific interstitial sites, causing partial lattice compression. The lattice compression causes a decrease in electrical resistance. This work is expected to contribute to the development of high-performance H sensors using Pd-based alloys.