Due to the wide and adjustable emission range,Ce^(3+)is an indispensable luminous center for full spectrum lighting.However,it needs to be sintered at high temperature in a reducing atmosphere,resulting in difficulty ...Due to the wide and adjustable emission range,Ce^(3+)is an indispensable luminous center for full spectrum lighting.However,it needs to be sintered at high temperature in a reducing atmosphere,resulting in difficulty to coexisting with other multivalent activated ions(such as Eu^(3+),Tm^(3+)),which greatly hinders the formation of full spectrum.In this study,a calcium vacancy enhanced self-reduction of Ce^(4+)is realized in CaNaSb_(2)O_(6)F(CNSOF)host under air atmosphere sintering,through which Ce^(3+),Tm^(3+)and Eu^(3+)coexisting in a single-phase full spectrum phosphor was prepared.Notably,the artificial introduction of a calcium vacancy was designed to verify this self-reduction mechanism.Moreover,the energy transfer kinetics among Tm^(3+),Ce^(3+)and Eu^(3+)were explored.Finally,combined with a 340 nm UV chip,a full spectrum phosphor-converted light-emitting diode(pc-LED)was fabricated,showing a broad emission range from 400 to 750 nm,Commission Internationale de I'Edairage(CIE)of(0.3485,0.3673),Ra of 92 and correlated color temperature(CCT)of 4933 K.Utilizing the variation in emission colors of this phosphor under different UV wavelengths,a dual encryption method combining point character code and fluorescent encryption technique is proposed.This work provides an effective path for Ce^(4+)self-reduction to apply in full spectrum pc-LED and information encryption.展开更多
Developing high-efficiency catalyst is crucial for electrochemical conversion of carbon dioxide(CO_(2))to high-value products.In the present work,a three-chamber electrolysis cell has been developed for CO_(2)reductio...Developing high-efficiency catalyst is crucial for electrochemical conversion of carbon dioxide(CO_(2))to high-value products.In the present work,a three-chamber electrolysis cell has been developed for CO_(2)reduction to carbon monoxide(CO)in an organic electrolyte,with sodium hydroxide(NaOH)and chlorine(Cl_(2))produced as byproducts.In order to improve the performance of the three-chamber electrolyzer,a gallium-based(Ga-based)ternary-porous catalyst(Ga-In_(4)Ag_(9))has been fabricated.During the long-term electrolysis process,Ga-In_(4)Ag_(9)catalyst exhibits good performance toward CO_(2)reduction reaction(CO_(2)RR),the CO partial current density achieves to 139.21 mA·cm^(-2)at-2.4 V(vs.SHE),with the Faraday efficiency(FE)of CO formation stabled at 92.3%.Density functional theory(DFT)analysis reveals that the position of the d-band center of Ga-In_(4)Ag_(9)is regulated by silver(Ag)atoms,which is beneficial for enhancing the binding ability between the catalyst and the intermediate.Owing to the adsorption of Cl^(-)on the surface of Ga-In_(4)Ag_(9),the reconfiguration of electron density has been altered,which is beneficial for the stabilization of*CO_(2)-intermediate.This work provides valuable insights for designing Ga-based metal catalysts toward CO_(2)electrolysis to produce high-value chemicals.展开更多
基金Project supported by National Natural Science Foundation of China(62075203,12304460)Zhejiang Provincial Natural Science Foundation of China(LQ23A040007)Basic Public Welfare Research Program of Zhejiang Province(LDT23F05013F05)。
文摘Due to the wide and adjustable emission range,Ce^(3+)is an indispensable luminous center for full spectrum lighting.However,it needs to be sintered at high temperature in a reducing atmosphere,resulting in difficulty to coexisting with other multivalent activated ions(such as Eu^(3+),Tm^(3+)),which greatly hinders the formation of full spectrum.In this study,a calcium vacancy enhanced self-reduction of Ce^(4+)is realized in CaNaSb_(2)O_(6)F(CNSOF)host under air atmosphere sintering,through which Ce^(3+),Tm^(3+)and Eu^(3+)coexisting in a single-phase full spectrum phosphor was prepared.Notably,the artificial introduction of a calcium vacancy was designed to verify this self-reduction mechanism.Moreover,the energy transfer kinetics among Tm^(3+),Ce^(3+)and Eu^(3+)were explored.Finally,combined with a 340 nm UV chip,a full spectrum phosphor-converted light-emitting diode(pc-LED)was fabricated,showing a broad emission range from 400 to 750 nm,Commission Internationale de I'Edairage(CIE)of(0.3485,0.3673),Ra of 92 and correlated color temperature(CCT)of 4933 K.Utilizing the variation in emission colors of this phosphor under different UV wavelengths,a dual encryption method combining point character code and fluorescent encryption technique is proposed.This work provides an effective path for Ce^(4+)self-reduction to apply in full spectrum pc-LED and information encryption.
基金supported by the National Natural Science Foundation of China(Nos.52164048 and 52067012)the Natural Science Foundation of Kunming University of Science and Technology(No.KKZ3202437105)the Analysis and Testing Foundation of Kunming University of Science and Technology(No.2023P20221102026).
文摘Developing high-efficiency catalyst is crucial for electrochemical conversion of carbon dioxide(CO_(2))to high-value products.In the present work,a three-chamber electrolysis cell has been developed for CO_(2)reduction to carbon monoxide(CO)in an organic electrolyte,with sodium hydroxide(NaOH)and chlorine(Cl_(2))produced as byproducts.In order to improve the performance of the three-chamber electrolyzer,a gallium-based(Ga-based)ternary-porous catalyst(Ga-In_(4)Ag_(9))has been fabricated.During the long-term electrolysis process,Ga-In_(4)Ag_(9)catalyst exhibits good performance toward CO_(2)reduction reaction(CO_(2)RR),the CO partial current density achieves to 139.21 mA·cm^(-2)at-2.4 V(vs.SHE),with the Faraday efficiency(FE)of CO formation stabled at 92.3%.Density functional theory(DFT)analysis reveals that the position of the d-band center of Ga-In_(4)Ag_(9)is regulated by silver(Ag)atoms,which is beneficial for enhancing the binding ability between the catalyst and the intermediate.Owing to the adsorption of Cl^(-)on the surface of Ga-In_(4)Ag_(9),the reconfiguration of electron density has been altered,which is beneficial for the stabilization of*CO_(2)-intermediate.This work provides valuable insights for designing Ga-based metal catalysts toward CO_(2)electrolysis to produce high-value chemicals.
