Periodic Reporting for period 1 - PlasmoPore (Supported Porous Nanoparticles for Functional Plasmonic Materials)
Reporting period: 2021-04-01 to 2023-03-31
The development of renewable energy technologies is crucial for the goal of a global sustainable society. To realize this goals, one key research direction is the development of functional nanomaterials. In this context, metal nanoparticles have shown promise in diverse energy application from, e.g. photocatalyst and hydrogen detection.
Noble metal nanoparticles (e.g. gold, silver, palladium) support a phenomenon called localized surface plasmon resonances. Thanks to these resonances, metal nanoparticles are able to efficiently interact with light, e.g. scatter or absorb light much higher than its physical size and localize and amplify the corresponding electric field close to its surface. In particular for the latter, specific design of nanostructures can create the so-called “hot-spots” where the electric field is greatly enhanced. Such nanostructure includes pores in nanostructures. To this end, however, creation of pores in plasmonic particles are limited to colloidally-made particles, and thus they are not attached to a support.
Integrating controlled porosity into supported arrays of nanoparticles holds the key for their wide utilization in real devices. Along this spirit, the PlasmoPore project aims to establish a fabrication route to produce supported porous noble metal nanoparticles with highly tuneable physical parameters, by combining wet chemistry and nanolithography, and employ these structures in energy related applications such as hydrogen detection and photocatalysis.
Noble metal nanoparticles (e.g. gold, silver, palladium) support a phenomenon called localized surface plasmon resonances. Thanks to these resonances, metal nanoparticles are able to efficiently interact with light, e.g. scatter or absorb light much higher than its physical size and localize and amplify the corresponding electric field close to its surface. In particular for the latter, specific design of nanostructures can create the so-called “hot-spots” where the electric field is greatly enhanced. Such nanostructure includes pores in nanostructures. To this end, however, creation of pores in plasmonic particles are limited to colloidally-made particles, and thus they are not attached to a support.
Integrating controlled porosity into supported arrays of nanoparticles holds the key for their wide utilization in real devices. Along this spirit, the PlasmoPore project aims to establish a fabrication route to produce supported porous noble metal nanoparticles with highly tuneable physical parameters, by combining wet chemistry and nanolithography, and employ these structures in energy related applications such as hydrogen detection and photocatalysis.
The project has three technical work packages:
1. Fabrication of supported porous nanoparticles
2. Application as plasmonic hydrogen sensors
3. Application as plasmonic catalysis
We have explored the possibility to create porous gold and palladium nanoparticles by combining colloidal lithography and selective dealloying. In the process, we explored the use of gold-silver and palladium-aluminum alloys and finding suitable selective etchant to selectively remove silver and palladium, respectively, to create the pores. We did extensive nanofabrication to find the optimized alloy concentration and investigated the reaction time to fully dissolve the alloyant metals. To confirm the resulting dealloying, we use optical and structural characterization. To support the experimental part, we have also explored the use of Finite-Difference Time-Domain calculation to simulate their optical properties.
To support the application in hydrogen sensing, we have built a custom setup to allow optical measurements of the samples under controlled exposure to hydrogen gas. With this setup, samples comprising palladium nanoparticles was investigated for its response to hydrogen gas. For the catalysis, a flow reactor was used to see the functionality of gold nanoparticles in converting carbon monoxide into carbon dioxide.
At the end of the project, we have developed a recipe to create porous Au nanoparticles and, in addition, published an open access paper on a breakthrough work in the design of a highly sensitive hydrogen sensors, which is widely disseminated through web news portals, and filed a patent for the corresponding technology.
1. Fabrication of supported porous nanoparticles
2. Application as plasmonic hydrogen sensors
3. Application as plasmonic catalysis
We have explored the possibility to create porous gold and palladium nanoparticles by combining colloidal lithography and selective dealloying. In the process, we explored the use of gold-silver and palladium-aluminum alloys and finding suitable selective etchant to selectively remove silver and palladium, respectively, to create the pores. We did extensive nanofabrication to find the optimized alloy concentration and investigated the reaction time to fully dissolve the alloyant metals. To confirm the resulting dealloying, we use optical and structural characterization. To support the experimental part, we have also explored the use of Finite-Difference Time-Domain calculation to simulate their optical properties.
To support the application in hydrogen sensing, we have built a custom setup to allow optical measurements of the samples under controlled exposure to hydrogen gas. With this setup, samples comprising palladium nanoparticles was investigated for its response to hydrogen gas. For the catalysis, a flow reactor was used to see the functionality of gold nanoparticles in converting carbon monoxide into carbon dioxide.
At the end of the project, we have developed a recipe to create porous Au nanoparticles and, in addition, published an open access paper on a breakthrough work in the design of a highly sensitive hydrogen sensors, which is widely disseminated through web news portals, and filed a patent for the corresponding technology.
The project produced results beyond the state of the art in the field of nanoplasmonics and nanofabrication in that it adds the consisting library of plasmonic structures with highly functional porous nanoparticles. These results have potential impact for improving plasmonic applications such as in catalysis and sensing, with a wider potential in other fields, for example in electrochemistry. As a part of the project, a patent is also submitted, which may have economic impact in the future. The potential impact of the project to the wider audience is further amplified by the open access publication of one part of the sought applications, which will trigger subsequent ideas and works.