03376nas a2200337   4500008004100000022001400041245023000055210006900285260000800354490000700362520209900369653000702468653002602475653001402501653002702515653001802542653003002560653003002590653003402620653003402654100003002688700002002718700003302738700001802771700002702789700002002816700001802836700003602854700002402890856012402914       2024                        eng d  a1613-681000aAluminium, nitrogen-dual-doped reduced graphene oxide Co-existing with cobalt-encapsulated graphitic carbon nanotube as an activity modulated electrocatalyst for oxygen electrocatalyst for oxygen electrochemistry applications0 aAluminium nitrogendualdoped reduced graphene oxide Coexisting wi  cAUG0 v203 a<p>
	There is a rising need to create high-performing, affordable electrocatalysts in the new field of oxygen electrochemistry. Here, a cost-effective, activity-modulated electrocatalyst with the capacity to trigger both the oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER) in an alkaline environment is presented. The catalyst (Al, Co/N-rGCNT) is made up of aluminium, nitrogen-dual-doped reduced graphene oxide sheets co-existing with cobalt-encapsulated carbon nanotube units. Based on X-ray Absorption Spectroscopy (XAS) studies, it is established that the superior reaction kinetics in Al, Co/N-rGCNT over their bulk counterparts can be attributed to their electronic regulation. The Al, Co/N-rGCNT performs as a versatile bifunctional electrocatalyst for zinc-air battery (ZAB), delivering an open circuit potential approximate to 1.35 V and peak power density of 106.3 mW cm-2, which are comparable to the system based on Pt/C. The Al, Co/N-rGCNT-based system showed a specific capacity of 737 mAh gZn-1 compared to 696 mAh gZn-1 delivered by the system based on Pt/C. The DFT calculations indicate that the adsorption of Co in the presence of Al doping in NGr improves the electronic properties favoring ORR. Thus, the Al, Co/N-rGCNT-based rechargeable ZAB (RZAB) emerges as a highly viable and affordable option for the development of RZAB for practical applications. This manuscript reports the development of a new bifunctional catalyst that exhibits high activity and stability under practical operating conditions. The catalyst (Al, Co/N-rGCNT) is made up of aluminium, nitrogen-dual-doped reduced graphene oxide sheets co-existing with the in situ formed cobalt-encapsulated CNT units is synthesized by a scalable pyrolysis method in an inert Ar atmosphere. The developed electrocatalyst achieved enhanced the oxygen reduction reaction (ORR) and the oxygen evolution reaction OER activity as a result of the favorable synergistic modulations and the system can serve as a process-friendly air-electrode for rechargeable zinc-air battery (RZAB). image</p>
10aAl10aBifunctional catalyst10aDFT study10aencapsulated structure10aN-dual doping10aOxygen Evolution Reaction10aoxygen reduction reaction10arechargeable zinc-air battery10aX-ray absorption spectroscopy1 aKharabe, Geeta, Pandurang1 aBarik, Sidharth1 aVeeranmaril, Sudheesh, Kumar1 aNair, Aathira1 aIllathvalappil, Rajith1 aYoyakki, Athira1 aJoshi, Kavita1 aVinod, Chathakudath, Prabhakara1 aKurungot, Sreekumar  uhttps://library.ncl.res.in/content/aluminium-nitrogen-dual-doped-reduced-graphene-oxide-co-existing-cobalt-encapsulated02473nas a2200277   4500008004100000022001400041245010900055210006900164260000800233490000700241520149100248653001801739653003001757653003301787653002501820653002101845653004501866653003401911100003001945700002001975700001701995700001602012700001802028700002402046856012502070       2025                        eng d  a1613-681000aDefect-rich CoFe-alloy with engineered carbon support for high-performance rechargeable Zn-air batteries0 aDefectrich CoFealloy with engineered carbon support for highperf  cSEP0 v213 a<p>
	Defect-rich CoFe-alloy with engineered carbon support is synthesized as a bifunctional cathode, coupled with a modified electrode fabrication technique, for rechargeable zinc-air batteries (RZABs). The CoFe(2:1)/N-rGCNT-catalyst is synthesized by annealing graphene oxide (GO), cobalt and iron acetate, and melamine, leading to the in situ formation of CoFe alloy-encapsulated CNTs. This resulted in a unique layer-separated Fe-rich skin@CoFe alloy decorated nitrogen-doped graphene (NGr) with CoFe-encapsulated CNTs. The interplay of line defects, enhanced conductivity, and electronic modulation underpins electrocatalyst's performance. Electrochemical analysis revealed an onset potential of 955 mV vs RHE, a half-wave potential of 835 mV vs RHE for oxygen reduction reaction (ORR) and an overpotential of 340 mV for oxygen evolution reaction (OER), yielding a Delta E of 0.73 V, comparable to the reported catalysts. The 3D X-ray microtomography simulations suggest improved air permeability of CoFe(2:1)/N-rGCNT facilitates easier gas diffusion, contributing in better device performance. The RZAB with CoFe(2:1)/N-rGCNT-cathode exhibited a peak power density of 171.3 mW cm(-)2, surpassing 140.8 mW cm(-)2 obtained from a cell based on Pt/C-cathode. The Co/N-rGCNT-based battery achieved a stable discharge profile at 10 mA cm(-)2 with a specific capacity of 650 mAh g(-)(1)Zn, and in rechargeable mode, achieved 140 h of high-rate charge-discharge cycling capability.</p>
10a3D tomography10a<italic>N</italic>-doping10aalloy encapsulated structure10adevice demonstration10agrain boundaries10aoxygen reduction and evolution reactions10arechargeable zinc-air battery1 aKharabe, Geeta, Pandurang1 aBarik, Sidharth1 aTorris, Arun1 aMaria, Anit1 aKumar, Yogesh1 aKurungot, Sreekumar  uhttps://library.ncl.res.in/content/defect-rich-cofe-alloy-engineered-carbon-support-high-performance-rechargeable-zn-air