Abstract
Reduction-oxidation controls and synthesis of organic-inorganic hybrid structures are key features associated with their electrochemical properties. However, they involve bulky setup and long-time processes that incur high-cost. Herein, we report one-step combustion waves (CWs) for the fabrication of hybrid-porous palladium/palladium oxides/carbon (Pd/PdxOy@C) nanostructures with controllable atomic composition and their application as a high-performance pH sensor. Hybrid composites of Pd/formaldehyde (FA)/nitrocellulose (NC) were prepared as precursors. Self-propagating CWs through the NC networks carried out the transformation from Pd to PdO2 in the higher oxidation state and the formation of a carbon layer, while the fast release of chemicals in CWs developed the porous nanostructures with large surface areas. The flexible pH sensor using the synthesized Pd/PdxOy@C powders exhibited the outstanding specific voltage potential (2.08 V/mg at pH 2.83) and sensitivity (167 mV/mg pH). It showed no hysteresis during cycling of pH values and high stability over 4 h (voltage change <0.89%). The high oxidation states and conductive carbon layers of Pd/PdxOy@C with large surface areas improved the specific potential and the stability in minute changes of pH values and forward-reverse proton exchanges. The physicochemical synthesis using CWs would contribute to developing scalable processing for electrochemical applications, including chemical sensors.
Original language | English |
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Pages (from-to) | 37-46 |
Number of pages | 10 |
Journal | Sensors and Actuators, B: Chemical |
Volume | 274 |
DOIs | |
Publication status | Published - 2018 Nov 20 |
Bibliographical note
Funding Information:This work was supported by the Ministry of Trade, Industry & Energy (MOTIE, Korea) under the Industrial Technology Innovation Program ( 10080611 ), and the Korea Institute of Energy Technology Evaluation and Planning (KETEP) and the Ministry of Trade, Industry & Energy (MOTIE) of the Republic of Korea (Grant no. 20173010032170 ).
Publisher Copyright:
© 2018 Elsevier B.V.
Keywords
- Carbon coating
- Chemical potential
- Combustion synthesis
- High oxidation state
- Palladium oxide
- pH sensor
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Instrumentation
- Condensed Matter Physics
- Surfaces, Coatings and Films
- Metals and Alloys
- Electrical and Electronic Engineering
- Materials Chemistry