This work reports the synthesis,characterization,and energy focused applications of the novel lanthanides co-doped tantalum pentoxide hetero-system(Sm^(3+)-Eu^(3+)-Tm^(3+):Ta_(2)O_(5)).Ln^(3+)-doped Ta_(2)O_(5) expres...This work reports the synthesis,characterization,and energy focused applications of the novel lanthanides co-doped tantalum pentoxide hetero-system(Sm^(3+)-Eu^(3+)-Tm^(3+):Ta_(2)O_(5)).Ln^(3+)-doped Ta_(2)O_(5) express excellent opto-electronic features reflected by the narrow band gap energy of 3.87 eV.Different vibrations confirm the presence of Ta-O-Ta and Ta-O bonds.The synthesized system possesses orthorhombic geometry with 59.46 nm particle size.With the smoother and compact morphology,the synthesized material succeeds in augmenting the performance of different systems aimed at energy applications.Fully ambient perovskite solar cell device fabricated with the Ln^(3+)-doped Ta_(2)O_(5) as an electron transport layer excels in achieving an efficiency and fill factor of 14.17% and 76% under artificial sun.This device was marked by the negligible hysteresis behavior showing profound photovoltaic performance.The electrochemical activity of the Ln^(3+)-doped Ta_(2)O_(5) decorated electrode was evaluated for electrical charge storage potential with pseudocapacitive behavior,With the highest specific capacitance of 355.39 F/g and quicker ionic diffusion rate,the designed electrode excels conventionally used materials.Electro-catalysis of water with Ln^(3+)-doped Ta_(2)O_(5) material indicates its capacity for H_(2) production with the lowest overpotential and Tafel slope values of 148 and 121.2 mV/dec,while the O_(2) generation is comparatively lower.With the stable electrochemical output,this rare earth modified material has the potential to replace conventionally used environmentally perilous and costly materials.展开更多
We report the synthesis, characterisation and catalytic performance of two nature-inspired biomassderived electro-catalysts for the oxygen reduction reaction in fuel cells. The catalysts were prepared via pyrolysis of...We report the synthesis, characterisation and catalytic performance of two nature-inspired biomassderived electro-catalysts for the oxygen reduction reaction in fuel cells. The catalysts were prepared via pyrolysis of a real food waste（lobster shells） or by mimicking the composition of lobster shells using chitin and CaCO3 particles followed by acid washing. The simplified model of artificial lobster was prepared for better reproducibility. The calcium carbonate in both samples acts as a pore agent, creating increased surface area and pore volume, though considerably higher in artificial lobster samples due to the better homogeneity of the components. Various characterisation techniques revealed the presence of a considerable amount of hydroxyapatite left in the real lobster samples after acid washing and a low content of carbon（23%）, nitrogen and sulphur（〈1%）, limiting the surface area to 23 m^2/g, and consequently resulting in rather poor catalytic activity. However, artificial lobster samples, with a surface area of ≈200 m^2/g and a nitrogen doping of 2%, showed a promising onset potential, very similar to a commercially available platinum catalyst, with better methanol tolerance, though with lower stability in long time testing over 10,000 s.展开更多
Single-phase multiferroics(MFs)exhibiting ferroelectricity and ferromagnetism and the strong magnetoelectric(ME)coupling effect at room temperature are seen as key to the development of the next-generation of spintron...Single-phase multiferroics(MFs)exhibiting ferroelectricity and ferromagnetism and the strong magnetoelectric(ME)coupling effect at room temperature are seen as key to the development of the next-generation of spintronic devices,multi-state memories,logic devices and sensors.Herein,the single-tetragonal phase(1ex)(Sr_(0.3)Bi_(0.35)Na_(0.329)Li_(0.021))TiO_(3-x)BiFeO_(3)(x=0.2 or 0.4)system was designed to study the intrinsic ME coupling effect at room temperature and high frequencies.The polarization arises from the cooperative displacement of both Fe3t and Ti4t relative to the oxygen sublattice in the tetragonally distorted perovskite structure,and the magnetization stems from indirect exchange magnetic interaction between adjacent iron ions.A switchable voltage-controlled magnetization was confirmed by a change of the coercive magnetic field,Hc,and remnant magnetization,Mr,in the x=0.4 component subjected to an external electric field at room temperature and was possibly attributed to a strain-mediated ME coupling effect.In addition,resonance behaviours of the complex magnetic permeability and complex dielectric permittivity in the GHz band indicate that this ME effect is intrinsic in nature and could broaden the applications of multiferroics to devices operating at microwave frequencies.展开更多
基金supported by Researchers Supporting Project number RSP2023R176,King Saud University,Riyadh,Saudi Arabia。
文摘This work reports the synthesis,characterization,and energy focused applications of the novel lanthanides co-doped tantalum pentoxide hetero-system(Sm^(3+)-Eu^(3+)-Tm^(3+):Ta_(2)O_(5)).Ln^(3+)-doped Ta_(2)O_(5) express excellent opto-electronic features reflected by the narrow band gap energy of 3.87 eV.Different vibrations confirm the presence of Ta-O-Ta and Ta-O bonds.The synthesized system possesses orthorhombic geometry with 59.46 nm particle size.With the smoother and compact morphology,the synthesized material succeeds in augmenting the performance of different systems aimed at energy applications.Fully ambient perovskite solar cell device fabricated with the Ln^(3+)-doped Ta_(2)O_(5) as an electron transport layer excels in achieving an efficiency and fill factor of 14.17% and 76% under artificial sun.This device was marked by the negligible hysteresis behavior showing profound photovoltaic performance.The electrochemical activity of the Ln^(3+)-doped Ta_(2)O_(5) decorated electrode was evaluated for electrical charge storage potential with pseudocapacitive behavior,With the highest specific capacitance of 355.39 F/g and quicker ionic diffusion rate,the designed electrode excels conventionally used materials.Electro-catalysis of water with Ln^(3+)-doped Ta_(2)O_(5) material indicates its capacity for H_(2) production with the lowest overpotential and Tafel slope values of 148 and 121.2 mV/dec,while the O_(2) generation is comparatively lower.With the stable electrochemical output,this rare earth modified material has the potential to replace conventionally used environmentally perilous and costly materials.
基金the EU for the Intra European Marie Curie Research Fellowship (PIEFGA-2013-623227)
文摘We report the synthesis, characterisation and catalytic performance of two nature-inspired biomassderived electro-catalysts for the oxygen reduction reaction in fuel cells. The catalysts were prepared via pyrolysis of a real food waste（lobster shells） or by mimicking the composition of lobster shells using chitin and CaCO3 particles followed by acid washing. The simplified model of artificial lobster was prepared for better reproducibility. The calcium carbonate in both samples acts as a pore agent, creating increased surface area and pore volume, though considerably higher in artificial lobster samples due to the better homogeneity of the components. Various characterisation techniques revealed the presence of a considerable amount of hydroxyapatite left in the real lobster samples after acid washing and a low content of carbon（23%）, nitrogen and sulphur（〈1%）, limiting the surface area to 23 m^2/g, and consequently resulting in rather poor catalytic activity. However, artificial lobster samples, with a surface area of ≈200 m^2/g and a nitrogen doping of 2%, showed a promising onset potential, very similar to a commercially available platinum catalyst, with better methanol tolerance, though with lower stability in long time testing over 10,000 s.
基金support by the National Natural Science Foundation of China(Grant No.51972322)Z.H.would like to acknowledge the financial support by the Postdoctoral Fellowship Program of CPSF(No.GZC20232832)+5 种基金Queen Mary University of London and the China Scholarship Council(No.201806370199)for a joint Ph.D.scholarship.V.K.thanks the Grant Agency of the Slovak Academy of Sciences for support through Grant No.2/0034/23.H.Y.the financial support from the Royal Society a Newton Advanced Fellowship award(No.NAF\R1\201126)C.J.thanks the finacial support by the National Natural Science Foundation of China(No.12174164)the 111 Project under Grant No.B20063the Key R&D Project of Gansu Province(No.22YF7WA014).
文摘Single-phase multiferroics(MFs)exhibiting ferroelectricity and ferromagnetism and the strong magnetoelectric(ME)coupling effect at room temperature are seen as key to the development of the next-generation of spintronic devices,multi-state memories,logic devices and sensors.Herein,the single-tetragonal phase(1ex)(Sr_(0.3)Bi_(0.35)Na_(0.329)Li_(0.021))TiO_(3-x)BiFeO_(3)(x=0.2 or 0.4)system was designed to study the intrinsic ME coupling effect at room temperature and high frequencies.The polarization arises from the cooperative displacement of both Fe3t and Ti4t relative to the oxygen sublattice in the tetragonally distorted perovskite structure,and the magnetization stems from indirect exchange magnetic interaction between adjacent iron ions.A switchable voltage-controlled magnetization was confirmed by a change of the coercive magnetic field,Hc,and remnant magnetization,Mr,in the x=0.4 component subjected to an external electric field at room temperature and was possibly attributed to a strain-mediated ME coupling effect.In addition,resonance behaviours of the complex magnetic permeability and complex dielectric permittivity in the GHz band indicate that this ME effect is intrinsic in nature and could broaden the applications of multiferroics to devices operating at microwave frequencies.
