Gouse Azam | Central Electrochemical Research Institute (original) (raw)
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A more complex class of photo catalytically active material that has received less attention is t... more A more complex class of photo catalytically active material that has received less attention is the poly oxo metalate (POM) . Most POM clusters share the general photochemical characteristics of the semiconductor photo catalysts. POM anions include a large variety of oxygen bridged metal clusters well known for their rich photo catalytic action analogous to that of semiconductors. The POM are relatively non toxic and inexpensive. Their excited state, produced after absorption of UV -near visible light is a strong oxidant which is able to mineralize either directly or by radicals mediated oxidation of organic species including organic pollutants.
Nitrogen functionalization of graphite nanofibers (N-GNF) was performed using hexa methyl tetra a... more Nitrogen functionalization of graphite nanofibers (N-GNF) was performed using hexa methyl tetra amine (HMTA) as the nitrogen source and used as a support material for metal nanoparticle deposition. The successful incorporation of nitrogen was confirmed using X-ray photoelectron spectroscopy (XPS) and
The potential of graphite nanofiber (GNF)-Poly(3,4-ethylenedioxythiophene) (PEDOT) composite is e... more The potential of graphite nanofiber (GNF)-Poly(3,4-ethylenedioxythiophene) (PEDOT) composite is explored as a catalyst support for polymer electrolyte fuel cells (PEFCs). Due to electron accepting nature of GNF and electron donating nature of PEDOT, the monomer EDOT adsorbs on the surface of GNF due to strong electrostaticinteraction. Pt nanoparticles are impregnated on GNF-PEDOT composite by ethylene glycol reduction method and their effects on electro catalytic activity for oxygen reduction reaction (ORR) are systemically studied. Pt particles supported on GNF-PEDOT with catalyst loading of 0.2 mg cm −2 exhibit a peak power density of 537 mW cm −2 at a load current density of 1120 mA cm −2 , while it was only 338 mW cm −2 at a load current density of 720 mA cm −2 in case of Pt particles supported on pristine GNF. The superior behavior of GNF-PEDOT supported Pt catalyst could be exclusively credited to the high graphitic nature of GNF and their mild functionalization with PEDOT increasing uniform dispersion of Pt. Indeed, the non-destructive functionalization of GNF with conducting polymer, such as PEDOT, makes them promising catalyst-supports for PEFCs.
Blend membranes are fabricated from sulfonated poly(ether ether ketone) (SPEEK) and poly[bis(phen... more Blend membranes are fabricated from sulfonated poly(ether ether ketone) (SPEEK) and poly[bis(phenoxy)phosphazene] (POP). The effect of POP content on the distribution of ionic channels is investigated by atomic force microscopy (AFM). The water uptake and methanol permeability for the blend membranes are also investigated. The blend membranes are characterized in terms of their thermal and mechanical properties in conjunction with their ionic conductivity. The proton conductivity of the blend membranes slightly decreased with increasing POP content in comparison with the pristine SPEEK membrane. The hydrophobic nature of POP blocks the ionic channels in the SPEEK matrix, subsequently decreasing its water uptake and methanol permeability. The blend membranes showed higher power density compared to a pristine SPEEK membrane in direct methanol fuel cells (DMFCs).
Alkaline polymer electrolyte fuel cells Anion exchange membrane Polyphenylene oxide (PPO) Aryl su... more Alkaline polymer electrolyte fuel cells Anion exchange membrane Polyphenylene oxide (PPO) Aryl substitution Homogeneous quaternization a b s t r a c t Anion exchange membrane from poly(phenylene oxide) containing pendant quaternary ammonium groups is fabricated for application in alkaline polymer electrolyte fuel cells (APEFCs). Chloromethylation of poly(phenylene oxide) (PPO) was performed by aryl substitution and then homogeneously quaternized to form an anion exchange membrane (AEM). The influence of various parameters on the chloromethylation reaction was investigated and optimized. The successful introduction of the above groups in the polymer backbone was confirmed by 1 H NMR and FT-IR spectroscopy. Membrane intrinsic properties such as ion exchange capacity, water uptake and ionic conductivity were evaluated. The membrane electrolyte exhibited an enhanced performance in comparison with the state-of-the-art commercial AHA membrane in APEFCs. A peak power density of 111 mW/cm 2 at a load current density of 250 mA/cm 2 was obtained for PPO based membrane in APEFCs at 30 C.
A more complex class of photo catalytically active material that has received less attention is t... more A more complex class of photo catalytically active material that has received less attention is the poly oxo metalate (POM) . Most POM clusters share the general photochemical characteristics of the semiconductor photo catalysts. POM anions include a large variety of oxygen bridged metal clusters well known for their rich photo catalytic action analogous to that of semiconductors. The POM are relatively non toxic and inexpensive. Their excited state, produced after absorption of UV -near visible light is a strong oxidant which is able to mineralize either directly or by radicals mediated oxidation of organic species including organic pollutants.
Nitrogen functionalization of graphite nanofibers (N-GNF) was performed using hexa methyl tetra a... more Nitrogen functionalization of graphite nanofibers (N-GNF) was performed using hexa methyl tetra amine (HMTA) as the nitrogen source and used as a support material for metal nanoparticle deposition. The successful incorporation of nitrogen was confirmed using X-ray photoelectron spectroscopy (XPS) and
The potential of graphite nanofiber (GNF)-Poly(3,4-ethylenedioxythiophene) (PEDOT) composite is e... more The potential of graphite nanofiber (GNF)-Poly(3,4-ethylenedioxythiophene) (PEDOT) composite is explored as a catalyst support for polymer electrolyte fuel cells (PEFCs). Due to electron accepting nature of GNF and electron donating nature of PEDOT, the monomer EDOT adsorbs on the surface of GNF due to strong electrostaticinteraction. Pt nanoparticles are impregnated on GNF-PEDOT composite by ethylene glycol reduction method and their effects on electro catalytic activity for oxygen reduction reaction (ORR) are systemically studied. Pt particles supported on GNF-PEDOT with catalyst loading of 0.2 mg cm −2 exhibit a peak power density of 537 mW cm −2 at a load current density of 1120 mA cm −2 , while it was only 338 mW cm −2 at a load current density of 720 mA cm −2 in case of Pt particles supported on pristine GNF. The superior behavior of GNF-PEDOT supported Pt catalyst could be exclusively credited to the high graphitic nature of GNF and their mild functionalization with PEDOT increasing uniform dispersion of Pt. Indeed, the non-destructive functionalization of GNF with conducting polymer, such as PEDOT, makes them promising catalyst-supports for PEFCs.
Blend membranes are fabricated from sulfonated poly(ether ether ketone) (SPEEK) and poly[bis(phen... more Blend membranes are fabricated from sulfonated poly(ether ether ketone) (SPEEK) and poly[bis(phenoxy)phosphazene] (POP). The effect of POP content on the distribution of ionic channels is investigated by atomic force microscopy (AFM). The water uptake and methanol permeability for the blend membranes are also investigated. The blend membranes are characterized in terms of their thermal and mechanical properties in conjunction with their ionic conductivity. The proton conductivity of the blend membranes slightly decreased with increasing POP content in comparison with the pristine SPEEK membrane. The hydrophobic nature of POP blocks the ionic channels in the SPEEK matrix, subsequently decreasing its water uptake and methanol permeability. The blend membranes showed higher power density compared to a pristine SPEEK membrane in direct methanol fuel cells (DMFCs).
Alkaline polymer electrolyte fuel cells Anion exchange membrane Polyphenylene oxide (PPO) Aryl su... more Alkaline polymer electrolyte fuel cells Anion exchange membrane Polyphenylene oxide (PPO) Aryl substitution Homogeneous quaternization a b s t r a c t Anion exchange membrane from poly(phenylene oxide) containing pendant quaternary ammonium groups is fabricated for application in alkaline polymer electrolyte fuel cells (APEFCs). Chloromethylation of poly(phenylene oxide) (PPO) was performed by aryl substitution and then homogeneously quaternized to form an anion exchange membrane (AEM). The influence of various parameters on the chloromethylation reaction was investigated and optimized. The successful introduction of the above groups in the polymer backbone was confirmed by 1 H NMR and FT-IR spectroscopy. Membrane intrinsic properties such as ion exchange capacity, water uptake and ionic conductivity were evaluated. The membrane electrolyte exhibited an enhanced performance in comparison with the state-of-the-art commercial AHA membrane in APEFCs. A peak power density of 111 mW/cm 2 at a load current density of 250 mA/cm 2 was obtained for PPO based membrane in APEFCs at 30 C.