Hydrogen Solubility in Zirconium Alloys

Porous Pd–Sn Alloy Nanotube-Based Chemiresistor for Highly Stable and Sensitive H2 Detection

“…This observation is consistent with the understanding that alloying inhibits phase transitions and their associated volume changes. − Interestingly, the Pd–Sn alloy with a larger amount of Sn (≥18.8%) shows a decrease in the sensitivity, which is attributed to the decrease in the solubility of hydrogen due to having less of the Pd lattice for accommodating H atoms. In fact, an adequate amount of Sn (≤11.5%) is considered to be beneficial for enhancing the sensitivity owing to the grain boundary effect of bimetallic materials as mentioned previously . To sum up, while Sn itself is not active in hydrogen sensing, the presence of Sn helps improve the hydrogen sensing characteristics of Pd.…”

“…In fact, an adequate amount of Sn (≤11.5%) is considered to be beneficial for enhancing the sensitivity owing to the grain boundary effect of bimetallic materials as mentioned previously. 45 To sum up, while Sn itself is not active in hydrogen sensing, the presence of Sn helps improve the hydrogen sensing characteristics of Pd. The response time (T res ) and recovery time (T rec ) are also important indicators that describe the performance of gas sensors.…”

“…As shown in Figure S21, the Pd–Sn NTs showed the highest sensitivity of 4.8% toward 2% H 2 at 25 °C (m), whereas the sensitivities measured at 50 °C and 100 °C were 4.3% and 3.4%, respectively. The degradation of sensitivity at an elevated working temperature can be explained by Sieverts’ law, which clarified that the solubility of hydrogen in metal is inversely proportional to the temperature, as shown in eq − where C H is the concentration of H in the metal, p H 2 is the hydrogen pressure in Pa, T is the absolute temperature, and A and B are constants.…”