Researchers have developed a new 2D system by depositing platinum atoms on the carbon buffer layer's surface. This chemical sensor can be used to detect toxic gases such as benzene. (Image Credit: Chalmers University of Technology)
Researchers at the Chalmers University of Technology in Sweden and other universities have discovered a way to use one-thin platinum as a chemical sensor. This was achieved by depositing a schematic of platinum atoms on a carbon buffer layer's surface, which is a 2D graphene-like insulating material grown epitaxially on silicon carbide. This allows the 2D growth of platinum.
"In a nutshell, we managed to make a metal layer just one-atom-thick—sort of new material. We found that this atomically-thin metal is super sensitive to its chemical environment. Its electrical resistance changes significantly when it interacts with gasses," says Kyung Ho Kim, a postdoc at the Quantum Device Physics Laboratory at the Department of Microtechnology and Nanoscience at Chalmers, and lead author of the article. The basis of this study is to develop 2D materials beyond graphene.
The team says that atomically thin platinum can be useful for highly sensitive and fast-electrical detection of chemicals. They also observed platinum in great detail, but metals like palladium have created identical results.
Researchers utilized the sensitive chemical-to-electrical transduction capability of atomically thin platinum to detect hazardous gases at the parts-per-billion level. This was exhibited by using it to detect benzene, a carcinogenic compound that cannot be detected by an inexpensive device simply because it has not been developed.
"This new approach, using atomically thin metals, is very promising for future air-quality monitoring applications," says Jens Eriksson, Head of the Applied sensor science unit at Linköping University and a co-author of the paper.
Increasing the sensitivity of gas sensors by integrating nanostructured materials as the active sensing component can be complex due to the effects on the interfaces. Interfaces at nanoparticles, grains or contacts could result in a nonlinear current-voltage response, high electrical resistance, and finally, electric noise that causes a limitation on the sensor read-out.
This study shows that it's possible to prepare electrically constant platinum layers on one atom thickness by depositing physical vapor on the carbon zero layer grown epitaxially on silicon carbide. The new 2D system opens up opportunities to develop resilient and highly sensitive chemical sensors and can be the starting point for designing new heterogeneous catalysts with excellent activity and selectivity.
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