CeO_(2)is increasingly recognized as a viable polishing abrasive for SiO_(2)-based substrates,such as K9 glass,leveraging its intrinsic chemical mechanical polishing property.Although LaOF can improve the performance ...CeO_(2)is increasingly recognized as a viable polishing abrasive for SiO_(2)-based substrates,such as K9 glass,leveraging its intrinsic chemical mechanical polishing property.Although LaOF can improve the performance of CeO_(2)abrasive,the specific mechanism underlying this enhancement remains elusive.Herein,LaOF-CeO_(2)composite abrasive was prepared by co-precipitation method,aiming to elaborate on the influence of LaOF on the abrasive's polishing efficiency.It is found that the integration of LaOF results in the formation of LaOF-CeO_(2)composite characterized by a remarkably reduced primary particle size of approximately 41 nm,which primarily accounts for the improvement in polishing performance.Furthermore,the increasement in Ce^(3+)content and the Zeta potential both contribute to the superior function of the composite abrasive.Notably,the synergistic effect of these parameters is manifested in an elevated material removal rate reaching 1091.197 nm/min,coupled with a minimized surface roughness of as low as 0.546 nm when applied to K9 glass surface.The findings of this work offer novel insights into the role of LaOF in facilitating the performance of Ce-based abrasives,potentially influencing future advancements in the field of precision surface processing.展开更多
Fluoride nanoparticles of Ln3＋（Ln3＋=Pr3＋, Nd3＋, Sm3＋, Cod3＋,Tb3＋ Dy3＋, I-I03＋, Er3＋, Tm3＋, yb3＋）/Eu3＋：LaOF and Eu3＋：LaOF with rhombohedral crystal structure were prepared by a hydrothermal-sintering ...Fluoride nanoparticles of Ln3＋（Ln3＋=Pr3＋, Nd3＋, Sm3＋, Cod3＋,Tb3＋ Dy3＋, I-I03＋, Er3＋, Tm3＋, yb3＋）/Eu3＋：LaOF and Eu3＋：LaOF with rhombohedral crystal structure were prepared by a hydrothermal-sintering method. The red fluorescence emission of Eu3＋ ions was found to be enhanced with most of the co-dopant Ln3. ions. Compared with strong fluorescence emission at 610 nm of Eu3＋：LaOF nanoparticles, the enhancement factors was up to ten times in Ln3~ （Ln3＋=Gd3＋, Dy3＋, Tm3＋）FEu3＋：LaOF co-doped nanoparticles. The results show that the asymmetry of the local environment of Eu3＋ ion was reduced by co-doping Ln3＋ ion into the nanoparticles, and that energy transfer might occur between Eu3_ and codopant Ln3＋ ions, which is suggested as the source of the observed fluorescence enhancement.展开更多
Photocatalytic fixation of nitrogen has been recognized as a green and promising strategy for ammonia synthesis under ambient conditions.However,the efficient reduction of nitrogen remains a challenge due to high acti...Photocatalytic fixation of nitrogen has been recognized as a green and promising strategy for ammonia synthesis under ambient conditions.However,the efficient reduction of nitrogen remains a challenge due to high activation energy of nitrogen and low utilization of solar energy.Herein,lanthanum oxyfluoride with different doping content of Pr3+(LaOF:xPr3+)upconversion nanorods were synthesized by microwave hydrothermal method.Results indicated that the doping of Pr3+generated considerable defects on the surface of LaOF which acted as the adsorption and activation center for nitrogen.Meanwhile,the Pr3+ion narrowed the band gap and broadened the light response range of LaOF because LaOF:Pr3+can upconvert visible light into ultraviolet light,which excite LaOF nanorods and improve the utilization of solar light.The doping amount of Pr3+had critical effect on the photocatalytic nitrogen fixation performance which reached as high as 180μmol·L?1·ho1 when the molar ratio of Pr3+to LaOF was optimized to be 2%.展开更多
基金Project supported by the National Natural Science Foundation of China (21971129, 21961022, 21661023)the Inner Mongolia Autonomous Region 2022 Leading Talent Team of Science and Technology (2022LJRC0008)+6 种基金the Natural Science Foundation of Inner Mongolia Autonomous Region of China(2022MS02014, 2021BS02007)the Program for Innovative Research Team in Universities of Inner Mongolia Autonomous Region (NJYT23031)the 111 Project(D20033)the “Grassland Leading Talent” Program of Inner Mongoliathe “Grassland-Talent” Innovation Team of Inner Mongoliathe “Science and Technology for a Better Development of Inner Mongolia” Program (2020XM03)the Science and Technology Project of Ordos (2021 ZDI 11-14)。
文摘CeO_(2)is increasingly recognized as a viable polishing abrasive for SiO_(2)-based substrates,such as K9 glass,leveraging its intrinsic chemical mechanical polishing property.Although LaOF can improve the performance of CeO_(2)abrasive,the specific mechanism underlying this enhancement remains elusive.Herein,LaOF-CeO_(2)composite abrasive was prepared by co-precipitation method,aiming to elaborate on the influence of LaOF on the abrasive's polishing efficiency.It is found that the integration of LaOF results in the formation of LaOF-CeO_(2)composite characterized by a remarkably reduced primary particle size of approximately 41 nm,which primarily accounts for the improvement in polishing performance.Furthermore,the increasement in Ce^(3+)content and the Zeta potential both contribute to the superior function of the composite abrasive.Notably,the synergistic effect of these parameters is manifested in an elevated material removal rate reaching 1091.197 nm/min,coupled with a minimized surface roughness of as low as 0.546 nm when applied to K9 glass surface.The findings of this work offer novel insights into the role of LaOF in facilitating the performance of Ce-based abrasives,potentially influencing future advancements in the field of precision surface processing.
基金supported by the National Natural Science Foundation of China (Grant No. 11174190)the Fundamental Research Funds for the Central Universities (Grant No. GK201101006)+1 种基金Shaanxi Normal University, the Natural Science Foundation (Grant No. NZ11252)the Key Technologies R&D Program (Grant No.08222-19) of Ningxia Province,China
文摘Fluoride nanoparticles of Ln3＋（Ln3＋=Pr3＋, Nd3＋, Sm3＋, Cod3＋,Tb3＋ Dy3＋, I-I03＋, Er3＋, Tm3＋, yb3＋）/Eu3＋：LaOF and Eu3＋：LaOF with rhombohedral crystal structure were prepared by a hydrothermal-sintering method. The red fluorescence emission of Eu3＋ ions was found to be enhanced with most of the co-dopant Ln3. ions. Compared with strong fluorescence emission at 610 nm of Eu3＋：LaOF nanoparticles, the enhancement factors was up to ten times in Ln3~ （Ln3＋=Gd3＋, Dy3＋, Tm3＋）FEu3＋：LaOF co-doped nanoparticles. The results show that the asymmetry of the local environment of Eu3＋ ion was reduced by co-doping Ln3＋ ion into the nanoparticles, and that energy transfer might occur between Eu3_ and codopant Ln3＋ ions, which is suggested as the source of the observed fluorescence enhancement.
基金This work was supported by the National Natural Science Foundation of China(Grant Nos.51674043 and 51702026)the Postgraduate Research&Practice Innovation Program of Jiangsu Province(SJCX18_0951).
文摘Photocatalytic fixation of nitrogen has been recognized as a green and promising strategy for ammonia synthesis under ambient conditions.However,the efficient reduction of nitrogen remains a challenge due to high activation energy of nitrogen and low utilization of solar energy.Herein,lanthanum oxyfluoride with different doping content of Pr3+(LaOF:xPr3+)upconversion nanorods were synthesized by microwave hydrothermal method.Results indicated that the doping of Pr3+generated considerable defects on the surface of LaOF which acted as the adsorption and activation center for nitrogen.Meanwhile,the Pr3+ion narrowed the band gap and broadened the light response range of LaOF because LaOF:Pr3+can upconvert visible light into ultraviolet light,which excite LaOF nanorods and improve the utilization of solar light.The doping amount of Pr3+had critical effect on the photocatalytic nitrogen fixation performance which reached as high as 180μmol·L?1·ho1 when the molar ratio of Pr3+to LaOF was optimized to be 2%.
