Cerium fluoride(CeF_(3))semiconductor with upconversion property was constructed on graphite carbonitride(g-C_(3) N_(4))nanosheets by microwave hydrothermal method.The X-ray diffraction,transmission election microscop...Cerium fluoride(CeF_(3))semiconductor with upconversion property was constructed on graphite carbonitride(g-C_(3) N_(4))nanosheets by microwave hydrothermal method.The X-ray diffraction,transmission election microscopy,Fourier transform infrared,and X-ray photoelectron spectra techniques were used to characterize the CeF_(3)/g-C_(3)N_(4) nanocomposite.The study shows that CeF_(3) has upconversion property and can convert visible light(Vis)and near-infrared light(NIR)into ultraviolet light(UV).Mo reover,CeF3 and g-C_(3) N_(4) can form well-defined heterojunction and promote the effective separation of photogenerated electrons and holes.The synergistic effect of the CeF_(3)/g-C_(3)N_(4) nanocomposite was evaluated by photocatalytic degradation of dibenzothiophene(DBT).The optimum photocatalyst of CeF_(3)/g-C_(3)N_(4)(40 wt%)composites exhibit the highest photocatalytic desulfurization rate of the model oil under visible light radiation.展开更多
Solar driven nitrogen(N_(2))fixation to synthesize ammonia is a potential alternative for the traditional Haber-Bosch approach to meeting industrial demand,but is largely hampered by the difficulties in the harvesting...Solar driven nitrogen(N_(2))fixation to synthesize ammonia is a potential alternative for the traditional Haber-Bosch approach to meeting industrial demand,but is largely hampered by the difficulties in the harvesting of solar energy and activating inert N_(2).In this work,hollow CeF_(3) nanospheres co-doped with activator Tm^(3+)and sensitizer Yb^(3+)(Yb^(3+):Tm^(3+):CeF_(3))were prepared by microwave hydrothermal method.The product was employed as a catalyst for photo-driven N_(2) fixation by adjusting the molar ratio of Ce^(3+):Yb^(3+):Tm^(3+).Results show that the porous hollow structure enhances the light-harvesting by physical scattering and reflection.In addition,heteroatom doping generates abundant fluorine vacancies(F_(V))which provide abundant active sites for adsorption and activation of N_(2).The sample with molar ratio of CeF_(3):Yb^(3+):Tm^(3+)at 178:20:2 demonstrates the highest utilization of solar energy attributed to the strongest upconversion capability of near-infrared(NIR)light to visible and ultraviolet(UV)light,and the NH_(4)+concentration achieves the highest value of 15.06μmol/(gcat∙h)under simulated sunlight while nearly 6.22μmol/(gcat∙h)under NIR light.Current study offers a promising and sustainable strategy for the fixation of atmospheric N_(2) using full-spectrum solar energy.展开更多
Nickel-rich LiNi_(x)Co_(y)Mn_(1-x-y)O_(2)(NCM)cathodes,pivotal for high-energy-density lithium-ion batteries,face severe challenges from surface residual lithium compounds and hydrofluoric acid(HF)-induced degradation...Nickel-rich LiNi_(x)Co_(y)Mn_(1-x-y)O_(2)(NCM)cathodes,pivotal for high-energy-density lithium-ion batteries,face severe challenges from surface residual lithium compounds and hydrofluoric acid(HF)-induced degradation.These issues accelerate capacity fading,exacerbate interfacial polarization,and compromise safety.To address these issues,we proposed a scalable CeF_(3)/H_(3)BO_(3)hybrid coating strategy for LiNi_(0.82)Co_(0.12)Mn_(0.06)O_(2)cathodes.The CeF_(3)nanoparticles served as a robust physical barrier,effectively scavenging HF,while the LiBO_(2)layer derived from H_(3)BO_(3)eliminated residual Li_(2)CO_(3)through chemical conversion and established rapid Li^(+)transport pathways.Dynamic B-O bond reorganization enabled self-repair of coating defects,synergistically suppressing interfacial polarization and maintaining structural integrity.Electrochemical evaluations demonstrated that the hybridcoated cathode achieves 94%capacity retention after 200 cycles at 1C(2.8-4.3 V),significantly outperforming the pristine NCM(56.3%).Additionally,the modified cathode exhibits enhanced air stability,with suppressed H_(2)O/CO_(2)infiltration,and delivers 80%capacity retention after 1000 cycles in practical pouch cells.This work provides a costeffective and industrially viable solution to simultaneously mitigate HF corrosion,residual lithium accumulation,and cathode-electrolyte interphase instability,paving the way for durable high-energy-density batteries.展开更多
基金supported by the National Natural Science Foundation of China(11774178,51801172)the Jiangsu Province Key Laboratory of Materials Surface Science and Technology and School-level Research Projects of Yancheng Institute of Technology(xjr2019026)。
文摘Cerium fluoride(CeF_(3))semiconductor with upconversion property was constructed on graphite carbonitride(g-C_(3) N_(4))nanosheets by microwave hydrothermal method.The X-ray diffraction,transmission election microscopy,Fourier transform infrared,and X-ray photoelectron spectra techniques were used to characterize the CeF_(3)/g-C_(3)N_(4) nanocomposite.The study shows that CeF_(3) has upconversion property and can convert visible light(Vis)and near-infrared light(NIR)into ultraviolet light(UV).Mo reover,CeF3 and g-C_(3) N_(4) can form well-defined heterojunction and promote the effective separation of photogenerated electrons and holes.The synergistic effect of the CeF_(3)/g-C_(3)N_(4) nanocomposite was evaluated by photocatalytic degradation of dibenzothiophene(DBT).The optimum photocatalyst of CeF_(3)/g-C_(3)N_(4)(40 wt%)composites exhibit the highest photocatalytic desulfurization rate of the model oil under visible light radiation.
基金Project supported by the National Natural Science Foundation of China (51674043,51702026)。
文摘Solar driven nitrogen(N_(2))fixation to synthesize ammonia is a potential alternative for the traditional Haber-Bosch approach to meeting industrial demand,but is largely hampered by the difficulties in the harvesting of solar energy and activating inert N_(2).In this work,hollow CeF_(3) nanospheres co-doped with activator Tm^(3+)and sensitizer Yb^(3+)(Yb^(3+):Tm^(3+):CeF_(3))were prepared by microwave hydrothermal method.The product was employed as a catalyst for photo-driven N_(2) fixation by adjusting the molar ratio of Ce^(3+):Yb^(3+):Tm^(3+).Results show that the porous hollow structure enhances the light-harvesting by physical scattering and reflection.In addition,heteroatom doping generates abundant fluorine vacancies(F_(V))which provide abundant active sites for adsorption and activation of N_(2).The sample with molar ratio of CeF_(3):Yb^(3+):Tm^(3+)at 178:20:2 demonstrates the highest utilization of solar energy attributed to the strongest upconversion capability of near-infrared(NIR)light to visible and ultraviolet(UV)light,and the NH_(4)+concentration achieves the highest value of 15.06μmol/(gcat∙h)under simulated sunlight while nearly 6.22μmol/(gcat∙h)under NIR light.Current study offers a promising and sustainable strategy for the fixation of atmospheric N_(2) using full-spectrum solar energy.
基金financially supported by the National Key Research and Development Program(No.2022YFC3900905)the National Natural Science Foundation of China(No.52234001)the Science and Technology Planning Project of Hunan Province(No.2018TP1017)
文摘Nickel-rich LiNi_(x)Co_(y)Mn_(1-x-y)O_(2)(NCM)cathodes,pivotal for high-energy-density lithium-ion batteries,face severe challenges from surface residual lithium compounds and hydrofluoric acid(HF)-induced degradation.These issues accelerate capacity fading,exacerbate interfacial polarization,and compromise safety.To address these issues,we proposed a scalable CeF_(3)/H_(3)BO_(3)hybrid coating strategy for LiNi_(0.82)Co_(0.12)Mn_(0.06)O_(2)cathodes.The CeF_(3)nanoparticles served as a robust physical barrier,effectively scavenging HF,while the LiBO_(2)layer derived from H_(3)BO_(3)eliminated residual Li_(2)CO_(3)through chemical conversion and established rapid Li^(+)transport pathways.Dynamic B-O bond reorganization enabled self-repair of coating defects,synergistically suppressing interfacial polarization and maintaining structural integrity.Electrochemical evaluations demonstrated that the hybridcoated cathode achieves 94%capacity retention after 200 cycles at 1C(2.8-4.3 V),significantly outperforming the pristine NCM(56.3%).Additionally,the modified cathode exhibits enhanced air stability,with suppressed H_(2)O/CO_(2)infiltration,and delivers 80%capacity retention after 1000 cycles in practical pouch cells.This work provides a costeffective and industrially viable solution to simultaneously mitigate HF corrosion,residual lithium accumulation,and cathode-electrolyte interphase instability,paving the way for durable high-energy-density batteries.
