Hexaferrites'magnetic and structural properties are highly sensitive to changes in sintering temperature and cationic replacements.We fabricated Ca_(0.5)Cu_(0.5)Fe_(12-x)DyxO_(19)hexaferrites using the sol-gel tec...Hexaferrites'magnetic and structural properties are highly sensitive to changes in sintering temperature and cationic replacements.We fabricated Ca_(0.5)Cu_(0.5)Fe_(12-x)DyxO_(19)hexaferrites using the sol-gel technique.We examined the phase,microstructure and magnetic aspects of the samples with respect to varying doping of rare earth dysprosium.The results show the expansion in the lattice upon incorporation of dysprosium against iron.Morphological studies confirm the uniform distribution of particles with slightly longitudinal nanoflakes in one direction.Magnetic investigations show an increase in magnetic saturation(Ms)with increasing dysprosium incorporation till optimum level is achieved for 15%doping concentration,with negligible change for maximum doping level.Furthermore,coercivity(Hc)and magnetic moment(mB)in terms of Bohr's magneton(μB)also show an increasing trend with dysprosium substitution levels.The maximum saturation magnetization of 33.355 emu/g is achieved with magnetic remanence of 18.290 emu/g,along with optimum magnetic moment of 6.249μB.In addition to the traditional magnetic parameters,magnetic anisotropy parameters were explored for the deep insights into magnetic parameters.These outcomes suggest that improved magnetic properties of Ca_(0.5)Cu_(0.5)Fe_(12-x)DyxO_(19)ferrites make it good substitute for storage devices,magnetic filters,and other magnetic applications.展开更多
Seawater electrolysis for green hydrogen production is a promising approach toward achieving carbon neutrality.However,the abundance of Cl^(−)in seawater can severely corrode catalytic sites,significantly reducing the...Seawater electrolysis for green hydrogen production is a promising approach toward achieving carbon neutrality.However,the abundance of Cl^(−)in seawater can severely corrode catalytic sites,significantly reducing the lifespan of seawater electrolysis systems.Herein,we present metal ion-chelated tannic acid nanoparticles anchored on the CoFe layered double hydroxide nanosheet array on nickel foam(CoFe LDH@CoFe-TA/NF),synthesized via an interfacial coordination assembly method,serving as an efficient and stable electrocatalyst for alkaline seawater oxidation(ASO).The formed CoFe-TA nanoparticles promote the transformation of Co^(3+)into the more robust acid Co^(4+),thereby favoring the adsorption of the hard base OH^(−)rather than the soft base Cl^(−).In addition,the CoFe-TA ligand network effectively inhibits metal ion leaching and stabilizes active sites.As a result,the CoFe LDH@CoFe-TA/NF electrode requires a low overpotential of only 379 mV to obtain a current density of 1000 mA cm^(−2)in 1 M KOH+seawater.Furthermore,the electrode also shows a stable operation for 450 h at an industrial-level current density,underscoring its potential for sustainable energy applications.展开更多
基金the Deanship of Scientific Research at King Khalid University for funding this work through a large group Research Project under grant(RGP2/111/45)。
文摘Hexaferrites'magnetic and structural properties are highly sensitive to changes in sintering temperature and cationic replacements.We fabricated Ca_(0.5)Cu_(0.5)Fe_(12-x)DyxO_(19)hexaferrites using the sol-gel technique.We examined the phase,microstructure and magnetic aspects of the samples with respect to varying doping of rare earth dysprosium.The results show the expansion in the lattice upon incorporation of dysprosium against iron.Morphological studies confirm the uniform distribution of particles with slightly longitudinal nanoflakes in one direction.Magnetic investigations show an increase in magnetic saturation(Ms)with increasing dysprosium incorporation till optimum level is achieved for 15%doping concentration,with negligible change for maximum doping level.Furthermore,coercivity(Hc)and magnetic moment(mB)in terms of Bohr's magneton(μB)also show an increasing trend with dysprosium substitution levels.The maximum saturation magnetization of 33.355 emu/g is achieved with magnetic remanence of 18.290 emu/g,along with optimum magnetic moment of 6.249μB.In addition to the traditional magnetic parameters,magnetic anisotropy parameters were explored for the deep insights into magnetic parameters.These outcomes suggest that improved magnetic properties of Ca_(0.5)Cu_(0.5)Fe_(12-x)DyxO_(19)ferrites make it good substitute for storage devices,magnetic filters,and other magnetic applications.
基金the Deanship of Scientific Research at King Khalid University for funding support through a large group research project under Grant No.RGP2/119/45.
文摘Seawater electrolysis for green hydrogen production is a promising approach toward achieving carbon neutrality.However,the abundance of Cl^(−)in seawater can severely corrode catalytic sites,significantly reducing the lifespan of seawater electrolysis systems.Herein,we present metal ion-chelated tannic acid nanoparticles anchored on the CoFe layered double hydroxide nanosheet array on nickel foam(CoFe LDH@CoFe-TA/NF),synthesized via an interfacial coordination assembly method,serving as an efficient and stable electrocatalyst for alkaline seawater oxidation(ASO).The formed CoFe-TA nanoparticles promote the transformation of Co^(3+)into the more robust acid Co^(4+),thereby favoring the adsorption of the hard base OH^(−)rather than the soft base Cl^(−).In addition,the CoFe-TA ligand network effectively inhibits metal ion leaching and stabilizes active sites.As a result,the CoFe LDH@CoFe-TA/NF electrode requires a low overpotential of only 379 mV to obtain a current density of 1000 mA cm^(−2)in 1 M KOH+seawater.Furthermore,the electrode also shows a stable operation for 450 h at an industrial-level current density,underscoring its potential for sustainable energy applications.
