Development of carbon aerogels for various applications like catalyst for hydrogen isotope separation, water desalination, super capacitors and fuel cells.
The work on development of catalyst with long-term stability is being pursued for heavy water clean-up in collaboration with HWD-BARC.
Synthesis of Carbon Aerogel (CA):
The technology for the synthesis of carbon aerogels and metal loaded carbon aerogels has been developed.
Critical point drying method has been replaced by surfactant based open air-drying methods to prepare these aerogels.
High surface area carbon aerogels (CA) with surface area up to 2000 m2/g have been synthesized.
Various techniques have been developed to prepare carbon aerogels in different morphologies like large flat electrodes, thin film targets etc. for different applications.
Gel & Pyrolysed carbon aerogel (CA)
SEM of high surface area CA
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Platinum-loaded carbon aerogel (Pt-CA) for heavy water clean up:
Pt-CA with well dispersed nano-sized Pt particles was developed as a catalyst for application in hydrogen isotope separation. Pt-CA coated hydrophobic Dixon ring catalysts were developed under MOU with Heavy Water Board for bi-thermal hydrogen water exchange process.
This catalyst tested under dynamic conditions for H2-H2O exchange showed volume transfer coefficient of ~ 0.3 s-1 at atmospheric conditions.
The catalyst was conditioned for performing under 120 oC at 20 bar for hydrogen isotope production process.
Further Pt-CA catalyst is being tested for Heavy water clean-up in collaboration with HWD-BARC
TEM of Pt-CA showing Pt particles
Pt-CA coated Dixon ring catalyst
Batch of Pt-CA coated Dixon rings
Singh R et al., Development of hydrophobic platinum-doped carbon aerogel catalyst for H – D exchange process at high pressure, Current Science, Vol. 109, no. 10, p. 1860-1864, May. 2015.2.
Rashmi Singh et al. . Synthesis of platinum nanoparticles on carbon aerogel by ambient pressure drying method ,Materials Letter, 64 (2010)843-845.
Conducting carbon aerogel (CA) for capacitive deionization (CDI) application:
CA electrodes of size up to 200 x 200 mm have been synthesized for desalination application.
Specific capacitance of active electrode material = 80-120 F/g.
Salt sorption capacity of active electrode material = 8.4 mg per gram.
Multi-electrode desalination unit was made to remove salinity from 1000 ppm to less than 200 ppm with capacity of 500 ml per batch.
It was also found useful in removing arsenic from water from 200 ppb to less than 20 ppb.
Graphite supported large CA electrode
CDI setup for water desalination
CDI setup for arsenic removal
Kohli D.K et al., Capacitive deionization of ground water using carbon aerogel based electrodes ,Desalination and Water Treatment, Vol. 57, p. 26871-26879, Aug. 2016.
Carbon aerogel (CA) for Supercapacitor:
Currently work on development of heterogeneous carbon aerogels is under progress for achieving inherently conducting and wettable carbon materials supercapacitor application.
Capacitor cell was tested using N-doped CA and showed capacitance of 495 F at 0.7 V operation with ESR of 1.96 mΩ .
This material compares well with commercially available maxwell supercapacitor (ESR: 2.9 mΩ per cell).
Development of capacitor module of 5 kJ energy at 12 V operation is in progress.
Super capacitor cell demonstration
CV plot of CA & RuO2-CA
Singh Ashish et al. Ruthenium doped carbon aerogel with CO2 surface activation for enhanced electrochemical capacitance Current Applied Physics, Vol. 17, no. 6, p. 885-889, Aug. 2017
Pt-loaded carbon aerogel (Pt-CA) for fuel cell:
Pt-CA with 20% Pt loading is developed for fuel cell application.
A membrane electrode assembly fabricated with the prepared catalyst tested in PEMFCs (H2-O2) single cell showed power density of 536 mWcm-2 at 0.6V at 60°C under atmospheric pressure conditions.
Pt-CA performance for fuel cell
Singh R et al. Facile synthesis of highly conducting and mesoporous carbon aerogel as platinum support for PEM fuel cells International Journal of Hydrogen Energy, Vol. 42, p. 11110-11117, Aug. 2017
Carbon aerogel (CA) for X-ray emission:
X-ray emission studies have been conducted at BARC using carbon aerogel targets. The emission in the soft x-ray region was observed to increase to about 1.8 times and 2.3 times in pure and Pt doped carbon aerogel targets respectively with respect to solid carbon target.
Thin film CA target for laser interaction and SEM of crater formed with 8J, 500 ps laser
S. Chaurasia, et al. Laser interaction with low-density carbon foam Pramana: Journal of Physics , Vol. 75, p. 1191-1196, 2010.