Recent Advances in Palladium Nanoparticles-Based Hydrogen Sensors for Leak Detection

Abstract

Along with the development of hydrogen as a sustainable energy carrier, it is imperative to develop very rapid and sensitive hydrogen leaks sensors due to the highly explosive and flammable character of this gas. For this purpose, palladium-based materials are being widely investigated by research teams because of the high affinity between this metal and hydrogen. Furthermore, nanostructured palladium may provide improved sensing performances compared to the use of bulk palladium. This arises from a higher effective surface available for interaction of palladium with the hydrogen gas molecules. Several works taking advantage of palladium nanostructures properties for hydrogen sensing applications have been published. This paper reviews the recent advances reported in the literature in this scope. The electrical and optical detection techniques, most common ones, are investigated and less common techniques such as gasochromic and surface wave acoustic sensors are also addressed. Here, the sensor performances are mostly evaluated by considering their response time and limit of detection.

Photoacoustic Detection of H2 and NH3 Using Plasmonic Signal Enhancement in GaN Microcantilevers

“…As we saw in Figure 4, the SNR performance of the Pd-coated devices can be improved with optimization of the biasing conditions, which indicates that the LOD of the Pd device can be improved with further optimization of the biasing conditions. Nonetheless, the LOD obtained for our device using plasmonically enhanced photoacoustic detection technique is very comparable to the LOD exhibited by widely used surface plasmon resonance (SPR)-based techniques (lowest LOD was~10 ppm), the detection methods of which are much more cumbersome and bulky [61,62]. The performance of the Pd-coated devices was also tested when the analyte was diluted with air (with 60% relative humidity) and compared with the same when the analyte was diluted with N 2 .…”

Coulomb Blockade Effect in Well-Arranged 2D Arrays of Palladium Nano-Islands for Hydrogen Detection at Room Temperature: A Modeling Study

“…Despite decreasing the response of the sensor by lowering the concentration of hydrogen gas, our sensor response (S 1 ) exhibited a lower reduction rate in comparison with (S 2 ). In other words, by reducing the concentration of hydrogen gas—despite the declining trend in the response of both sensors—the ratio of the response of our sensor (S 1 ) to (S 2 ) is increasing.This suggests that our sensor could potentially be used for hydrogen gas leak detection, which needs a detection of concentration range, typically from 0.1% to less than 5% [ 18 ]. Since, in the subthreshold region, the IV characteristics of our sensor exhibited exponential behavior, it promised higher amounts of response due to the higher variation in electrical resistance in this region.…”

“…Many hydrogen gas sensors have been developed and studied, including electrochemical [ 3 , 4 ], conductometric [ 5 , 6 ], Schottky junction [ 7 ], field effect [ 8 ], optical [ 9 ], surface acoustic wave (SAW) [ 10 , 11 , 12 ], single-electron tunneling-based [ 13 ], and bulk acoustic wave [ 14 ], which operate based on different mechanisms. The most common operation mechanisms of hydrogen sensors are based on the changes in the electrical resistance, work function, optical properties and electrical current of selective material employed upon the adsorption and desorption of hydrogen gas [ 15 , 16 , 17 , 18 ]. The most sensitive hydrogen sensors are able to measure 0.1% hydrogen gas at temperatures between 0–45 °C with a response time of less than 15 s [ 17 ].…”

“…Among other mechanisms to detect H 2 , the prevalent palladium thin film technique, based on the random arrangement of nano-sized Pd clusters, has been found to be a simple and effective method [ 17 , 18 ]. Upon hydrogen exposure, the resistance of the sensor decreases due to expansion, connecting some of the nanoparticles and finally forming new pathways to pass the electrical current [ 17 , 18 , 22 ]. However, in the ultra-small grained Pd nano-pattern structure, a surface electron scattering mechanism has been observed, which increases the pathway of electrons in the channel.…”

Влияние Водорода На Оптическую Прозрачность Слоев Палладия

“…Несмотря на то, что изучение взаимодействия водорода с палладием началось ещё в конце 19-го века, многие детали этой проблемы до сих пор остаются до конца не изученными, и исследования продолжаются [1]. Металл платиновой группы палладий обладает рядом уникальных свойств, благодаря которым находит применение в различных отраслях промышленности.…”