The trade-off between efficiency and stability has limited the application of TiO_(2)as a catalyst due to its poor surface reactivity.Here,we present a modification of a TiO_(2)layer with highly stable Sub-5 nm Fe_(2)...The trade-off between efficiency and stability has limited the application of TiO_(2)as a catalyst due to its poor surface reactivity.Here,we present a modification of a TiO_(2)layer with highly stable Sub-5 nm Fe_(2)O_(3)nanoparticles(NP)by modulating its structure-surface reactivity relationship to attain efficiency-stability balance via a voltage-assisted oxidation approach.In situ simultaneous oxidation of the Ti substrate and Fe precursor using high-energy plasma driven by high voltage resulted in uniform distribution of Fe_(2)O_(3)NP embedded within porous TiO_(2)layer.Comprehensive surface characterizations with density functional theory demonstrated an improved electronic transition in TiO_(2)due to the presence of surface defects from reactive oxygen species and possible charge transfer from Ti to Fe;it also unexpectedly increased the active site in the TiO_(2)layer due to uncoordinated electrons in Sub-5 nm Fe_(2)O_(3)NP/TiO_(2)catalyst,thereby enhancing the adsorption of chemical functional groups on the catalyst.This unique embedded structure exhibited remarkable improvement in reducing 4-nitrophenol to 4-aminophenol,achieving approximately 99%efficiency in 20 min without stability decay after 20 consecutive cycles,outperforming previously reported TiO_(2)-based catalysts.This finding proposes a modified-electrochemical strategy enabling facile construction of TiO_(2)with nanoscale oxides extandable to other metal oxide systems.展开更多
Light emitting diodes(LEDs)have accounted for most of the lighting market as the technology matures and costs continue to reduce.As a new type of e-waste,LED is a double-edged sword,as it contains not only precious an...Light emitting diodes(LEDs)have accounted for most of the lighting market as the technology matures and costs continue to reduce.As a new type of e-waste,LED is a double-edged sword,as it contains not only precious and rare metals but also organic packaging materials.In previous studies,LED recycling focused on recovering precious and strategic metals while ignoring harmful substances such as organic packaging materials.Unlike crushing and other traditional methods,hydrothermal treatment can provide an environment-friendly process for decomposing packaging materials.This work developed a closed reaction vessel,where the degradation rate of plastic polyphthalamide(PPA)was close to 100%,with nano-TiO_(2)encapsulated in plastic PPA being efficiently recovered,while metals contained in LED were also recycled efficiently.Besides,the role of water in plastic PPA degradation that has been overlooked in current studies was explored and speculated in detail in this work.Environmental impact assessment revealed that the proposed recycling route for waste LED could significantly reduce the overall environmental impact compared to the currently published processes.Especially the developed method could reduce more than half the impact of global warming.Furthermore,this research provides a theoretical basis and a promising method for recycling other plastic-packaged e-waste devices,such as integrated circuits.展开更多
The study focused on the modification with platinum of dark defective titania obtained via pulsed laser ablation. Both the method of Pt introduction and the nature of the Pt precursor were varied. All samples exhibite...The study focused on the modification with platinum of dark defective titania obtained via pulsed laser ablation. Both the method of Pt introduction and the nature of the Pt precursor were varied. All samples exhibited similar phase compositions, specific surface areas, and Pt contents. High-resolution transmission electron microscopy coupled with pulsed CO adsorption revealed increased dispersity when photoreduction and the hydroxonitrate complex (Me _(4) N) _(2) [Pt _(2) (OH) _(2) (NO _(3) ) _(8) ] were used. The sample featured a high content of single-atom species and subnano-sized Pt clusters. The X-ray photoelectron spectroscopy results showed that the photoreduction method facilitated the appearance of a larger number of Pt ^(2+) states, which appeared owing to the strong metal-support interaction (SMSI) eff ect of the transfer of electron density from the electron-saturated defects on the TiO _(2) surface to Pt ^(4+) . In the hydrogen evolution reaction, samples with a significant fraction of the Pt ^(2+) ionic component, capable of generating short-lived Pt^(0) single-atom sites under irradiation due to the SMSI eff ect, exhibited the highest photocatalytic activity. The 0.5Pt(C)/TiO_(2) -Ph sample exhibited the highest hydrogen yield with a quantum efficiency of 0.53, retaining its activity even after 8 h of operation.展开更多
基金supported by the National Projects of the National Research Foundation(NRF)funded by Republic of Korea(#2022R1F1A1072739 and#2022R1A2C1004392)Prof.Nashrah is also grateful for financial supports by the YU Infra-Project in conjunction with BK21 FOUR National Program(#222A251009)by the Nano-Fab-NRF grant funded by Republic of Korea(#2009-0082580).
文摘The trade-off between efficiency and stability has limited the application of TiO_(2)as a catalyst due to its poor surface reactivity.Here,we present a modification of a TiO_(2)layer with highly stable Sub-5 nm Fe_(2)O_(3)nanoparticles(NP)by modulating its structure-surface reactivity relationship to attain efficiency-stability balance via a voltage-assisted oxidation approach.In situ simultaneous oxidation of the Ti substrate and Fe precursor using high-energy plasma driven by high voltage resulted in uniform distribution of Fe_(2)O_(3)NP embedded within porous TiO_(2)layer.Comprehensive surface characterizations with density functional theory demonstrated an improved electronic transition in TiO_(2)due to the presence of surface defects from reactive oxygen species and possible charge transfer from Ti to Fe;it also unexpectedly increased the active site in the TiO_(2)layer due to uncoordinated electrons in Sub-5 nm Fe_(2)O_(3)NP/TiO_(2)catalyst,thereby enhancing the adsorption of chemical functional groups on the catalyst.This unique embedded structure exhibited remarkable improvement in reducing 4-nitrophenol to 4-aminophenol,achieving approximately 99%efficiency in 20 min without stability decay after 20 consecutive cycles,outperforming previously reported TiO_(2)-based catalysts.This finding proposes a modified-electrochemical strategy enabling facile construction of TiO_(2)with nanoscale oxides extandable to other metal oxide systems.
基金financially supported by the National MCF Energy R&D Program of China(No.2018YFE0306100)the National Natural Science Foundation of China(No.51971249)。
基金supported by the National Natural Science Foundation of China(52270132).
文摘Light emitting diodes(LEDs)have accounted for most of the lighting market as the technology matures and costs continue to reduce.As a new type of e-waste,LED is a double-edged sword,as it contains not only precious and rare metals but also organic packaging materials.In previous studies,LED recycling focused on recovering precious and strategic metals while ignoring harmful substances such as organic packaging materials.Unlike crushing and other traditional methods,hydrothermal treatment can provide an environment-friendly process for decomposing packaging materials.This work developed a closed reaction vessel,where the degradation rate of plastic polyphthalamide(PPA)was close to 100%,with nano-TiO_(2)encapsulated in plastic PPA being efficiently recovered,while metals contained in LED were also recycled efficiently.Besides,the role of water in plastic PPA degradation that has been overlooked in current studies was explored and speculated in detail in this work.Environmental impact assessment revealed that the proposed recycling route for waste LED could significantly reduce the overall environmental impact compared to the currently published processes.Especially the developed method could reduce more than half the impact of global warming.Furthermore,this research provides a theoretical basis and a promising method for recycling other plastic-packaged e-waste devices,such as integrated circuits.
文摘The study focused on the modification with platinum of dark defective titania obtained via pulsed laser ablation. Both the method of Pt introduction and the nature of the Pt precursor were varied. All samples exhibited similar phase compositions, specific surface areas, and Pt contents. High-resolution transmission electron microscopy coupled with pulsed CO adsorption revealed increased dispersity when photoreduction and the hydroxonitrate complex (Me _(4) N) _(2) [Pt _(2) (OH) _(2) (NO _(3) ) _(8) ] were used. The sample featured a high content of single-atom species and subnano-sized Pt clusters. The X-ray photoelectron spectroscopy results showed that the photoreduction method facilitated the appearance of a larger number of Pt ^(2+) states, which appeared owing to the strong metal-support interaction (SMSI) eff ect of the transfer of electron density from the electron-saturated defects on the TiO _(2) surface to Pt ^(4+) . In the hydrogen evolution reaction, samples with a significant fraction of the Pt ^(2+) ionic component, capable of generating short-lived Pt^(0) single-atom sites under irradiation due to the SMSI eff ect, exhibited the highest photocatalytic activity. The 0.5Pt(C)/TiO_(2) -Ph sample exhibited the highest hydrogen yield with a quantum efficiency of 0.53, retaining its activity even after 8 h of operation.
