Fabrication Of Nickel-Cobalt Binary Free-Standing Materials With Enhanced Electrochemical Performance

Free-standing one-dimensional?1D?nanostructures possess many advantages over powder nanomaterials such as short transfer pathway and high collection capacity for charge carriers,direct electron tansport through the axial of the nanostructure and extremely high specific surface area.Nickel-based nanomaterials have been extensively explored due to they have high theoretical capacitance and excellent eletrocatalytic activities.However,poor conductivity and severe aggregation of nickel-based nanocomposites often reduce the performance of its practical applications.Herein,nickel-based materials were deposited on free-standing 1D TiO₂/C core-shell nanofiber arrays?TiO₂/C NFAs?to form composite nanostructures for high performance electrochemical sensors and supercapacitors.The specific research contents include:?1?Free-standing TiO₂/C NFAs were fabricated directly on a titanium foil to serve as the 1D conductive substrate by thermal chemical reaction with acetone.Nickel-cobalt binary nanoparticles were then deposited on the nanofibers by electrochemical deposition to form NiCo/TiO₂/C NFAs for enzymeless glucose sensing.The NiCo/TiO₂/C NFAs exhibit much improved sensitivity and excellent stability towards glucose determination,with a wide linear range from 1?M to 7658?M,and a high sensitivity of 975.3?A mM^-1 cm^-2.The detection limit is calculated to be 0.6?M?S/N=3?.The NiCo/TiO₂/C NFAs also show excellent selectivity with minimal interference from the coexistent species such as mannose,fructose,poly4-acetaminophen,uric acid,ascorbic acid,dopamine,and 5-hydroxytryptamine.The NiCo/TiO₂/C NFAs exhibit high reliability in practical applications,with a RSD of 3.11%and a recovery value of 98.66%for glucose determination in human serum.?2?NiCo layered double hydroxides?NiCo-LDH?were directly fabricated on free-standing TiO₂/C NFAs by electrochemical deposition for high performance supercapacitors.The NiCo-LDH/TiO₂/C NFAs electrode exhibits remarkable stability at high current density(75.1%at 75 mA cm^-2),excellent cycling stability(84.1%at 50mA cm^-2)after 5000 cycles,and high specific capacitance(1099.4 m F cm^-22 at 1 mA cm^-2).