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For the first time, a fast heating–cooling process is reported for the synthesis of carbon‐coated nickel (Ni) nanoparticles on a reduced graphene oxide (RGO) matrix (nano‐Ni@C/RGO) as a high‐performance H2O2fuel catalyst. The Joule heating temperature can reach up to ≈2400 K and the heating time can be less than 0.1 s. Ni microparticles with an average diameter of 2 µm can be directly converted into nanoparticles with an average diameter of 75 nm. The Ni nanoparticles embedded in RGO are evaluated for electro‐oxidation performance as a H2O2fuel in a direct peroxide–peroxide fuel cell, which exhibits an electro‐oxidation current density of 602 mA cm−2at 0.2 V (vs Ag/AgCl), ≈150 times higher than the original Ni microparticles embedded in the RGO matrix (micro‐Ni/RGO). The high‐temperature, fast Joule heating process also leads to a 4–5 nm conformal carbon coating on the surface of the Ni nanoparticles, which anchors them to the RGO nanosheets and leads to an excellent catalytic stability. The newly developed nano‐Ni@C/RGO composites by Joule heating hold great promise for a range of emerging energy applications, including the advanced anode materials of fuel cells.
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Fabric-infused array of reduced graphene oxide sensors for mapping of skin temperatures
We report a textile-infused sensor array, utilizing reduced graphene oxide (rGO) as a uniquely conformal negative temperature coefficient (NTC) material, for spatiotemporal mapping of skin temperatures. Nylon filaments were coated with rGO and stitched along with Ag conductive threads into a polyester fabric to create the array of individually addressable 6 × 6 NTC sensing elements. The temperature-mapping attribute of the sensor array was evaluated in comparison to infrared imaging. The rGO film remained mechanically and electrically stable upon stretching (<4% strain) and bending (<34°) of the filaments, demonstrating its conformal nature. These results suggest the intriguing possibility of thermally mapping topographically complex skin surfaces in a non-invasive, wearable, and cost effective manner.
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- Award ID(s):
- 1648057
- PAR ID:
- 10066631
- Date Published:
- Journal Name:
- Sensors and actuators. A, Physical
- ISSN:
- 0924-4247
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1016/j.sna.2018.06.043
