biostudies-literature00600Unknown3(10)Ganguly DNickel-encapsulated nitrogen-doped carbon nanotubes (Ni-TiO₂-NCNTs) are synthesized via chemical vapor deposition by thermal decomposition of acetylene with acetonitrile vapor at 700 °C on the Ni-TiO₂ matrix. TiO₂ is used as a dispersant medium for Ni nanoparticles, which assists in higher CNT growth at high temperatures. A reference catalyst is made by following the similar procedure without acetonitrile vapor, which is called a Ni-TiO₂-CNT. Acid treatment of these two catalysts dissolved Ni on the surface of CNTs-NCNTs, producing catalysts with enhanced surface area and defects. The transmission electron microscopy-energy-dispersive X-ray spectra analysis of acid-treated version of the catalysts confirmed the presence of encapsulated Ni. Oxygen reduction reaction (ORR) activity of these catalysts was analyzed in 0.1 N KOH solution. Among these, the acid-treated Ni-TiO₂-NCNT exhibited highest ORR onset potential of 0.88 V versus reversible hydrogen electrode and a current density of 3.7 mA cm^-2 at 170 μg cm^-2 of catalyst loading. The stability of the acid-treated Ni-TiO₂-NCNT is proved by cyclic voltammetry and chronoamperometry measurements which are done for 800 cycles and 100 h, respectively. Primarily N doping of CNTs is the reason behind the improved ORR activity.ACS omega13609-13620https://www.ebi.ac.uk/biostudies/studies/S-EPMC6644947biostudies-literatureChemical Vapor Deposition-Grown Nickel-Encapsulated N-Doped Carbon Nanotubes as a Highly Active Oxygen Reduction Reaction Catalyst without Direct Metal-Nitrogen Coordination.PMC6644947Ganguly DRamanujam KSundara R60falseChemical Vapor Deposition-Grown Nickel-Encapsulated N-Doped Carbon Nanotubes as a Highly Active Oxygen Reduction Reaction Catalyst without Direct Metal-Nitrogen Coordination.Nickel-encapsulated nitrogen-doped carbon nanotubes (Ni-TiO₂-NCNTs) are synthesized via chemical vapor deposition by thermal decomposition of acetylene with acetonitrile vapor at 700 °C on the Ni-TiO₂ matrix. TiO₂ is used as a dispersant medium for Ni nanoparticles, which assists in higher CNT growth at high temperatures. A reference catalyst is made by following the similar procedure without acetonitrile vapor, which is called a Ni-TiO₂-CNT. Acid treatment of these two catalysts dissolved Ni on the surface of CNTs-NCNTs, producing catalysts with enhanced surface area and defects. The transmission electron microscopy-energy-dispersive X-ray spectra analysis of acid-treated version of the catalysts confirmed the presence of encapsulated Ni. Oxygen reduction reaction (ORR) activity of these catalysts was analyzed in 0.1 N KOH solution. Among these, the acid-treated Ni-TiO₂-NCNT exhibited highest ORR onset potential of 0.88 V versus reversible hydrogen electrode and a current density of 3.7 mA cm^-2 at 170 μg cm^-2 of catalyst loading. The stability of the acid-treated Ni-TiO₂-NCNT is proved by cyclic voltammetry and chronoamperometry measurements which are done for 800 cycles and 100 h, respectively. Primarily N doping of CNTs is the reason behind the improved ORR activity.2018-01-01T00:00:00Z2018 Oct2024-02-14T20:17:44.436Z2019-08-31T07:04:11ZS-EPMC66449473145806610.1021/acsomega.8b01565