Ultrathin TiO_(2)nanosheets with coexposed{001}/{101}facets have attracted considerable attention because of their high photocatalytic activity.However,the charge-separated states in the TiO_(2)nanosheets must be exte...Ultrathin TiO_(2)nanosheets with coexposed{001}/{101}facets have attracted considerable attention because of their high photocatalytic activity.However,the charge-separated states in the TiO_(2)nanosheets must be extended to further enhance their photocatalytic activity for H_(2)evolution.Herein,we present a successful attempt to selectively dope lanthanide ions into the{101}facets of ultrathin TiO_(2)nanosheets with coexposed{001}/{101}facets through a facile one-step solvothermal method.The lanthanide doping slightly extended the light-harvesting region and markedly improved the charge-separated states of the TiO_(2)nanosheets as evidenced by UV-vis absorption and steady-state/transient photoluminescence spectra.Upon simulated sunlight irradiation,we observed a 4.2-fold enhancement in the photocatalytic H_(2)evolution activity of optimal Yb^(3+)-doped TiO_(2)nanosheets compared to that of their undoped counterparts.Furthermore,when Pt nanoparticles were used as cocatalysts to reduce the H_(2)overpotential in this system,the photocatalytic activity enhancement factor increased to 8.5.By combining these results with those of control experiments,we confirmed that the extended charge-separated states play the main role in the enhancement of the photocatalytic H_(2)evolution activity of lanthanide-doped TiO_(2)nanosheets with coexposed{001}/{101}facets.展开更多
{001}facets dominated single crystalline anatase TiO_(2) nanosheet array(TNSA)was synthe-sized through an optimized organic solvothermal route on uorine-doped tin oxide substrate.The field emission scanning electron m...{001}facets dominated single crystalline anatase TiO_(2) nanosheet array(TNSA)was synthe-sized through an optimized organic solvothermal route on uorine-doped tin oxide substrate.The field emission scanning electron microscopy images and X-ray diffraction patterns re-vealed that the{001}synthesized facets dominated TNSA exhibited much higher orientation than that synthesized by hydrothermal route.The TNSAs were loaded with Pt nanoparti-cles in uniformly size by using a photodecomposition method,which were further con rmed by high resolution transmission electron microscopy(HRTEM).The HRTEM images also revealed that Pt nanoparticles preferred to deposit on{001}facets.With loading of Pt nanoparticles,the optical absorbance was significantly enhanced,while the photolumines-cence(PL)was inhibited.The photocatalytic activity of TNSA was signi cantly improved by Pt loading and reached the maximum with optimal amount of Pt loading.The optimal amount of Pt on{001}facets is far less than that on TiO_(2) nanoparticles,which may be attributed to the specific atom structure of reactive{001}facets.展开更多
Anatase titanium(IV)oxide(TiO_(2))particles with exposed{001}and{101}facets were prepared by hydrothermal treatment of amorphous TiO_(2) with H_(2)O_(2)-NH_(3) solution.Crystal phase,shape,and size of TiO_(2) particle...Anatase titanium(IV)oxide(TiO_(2))particles with exposed{001}and{101}facets were prepared by hydrothermal treatment of amorphous TiO_(2) with H_(2)O_(2)-NH_(3) solution.Crystal phase,shape,and size of TiO_(2) particles are found to be greatly dependent on the ratio of H_(2)O_(2)-NH_(3) solution.The prepared TiO_(2) particles with specific exposed crystal faces show higher photocatalytic activity for acetaldehyde decomposition than commercial spherical TiO_(2) particles.This result implies that recombination is prevented by spatial separation of redox sites in the particles because of selective migration of electrons and positive holes to specific exposed crystal faces and/or different reactivity of electrons and positive holes on the specific exposed crystal face.展开更多
Controllable growth of anatase TiO_(2)crystals with exposed high reactive crystal facets has aroused great attention in the fields of science and technology due to their unique structure-dependent properties.Recently,...Controllable growth of anatase TiO_(2)crystals with exposed high reactive crystal facets has aroused great attention in the fields of science and technology due to their unique structure-dependent properties.Recently,much effort has been paid to synthesize anatase TiO_(2)crystals with exposed high reactive{001}facets.Herein,we review the recent progress in synthesizing{001}facets dominated anatase TiO_(2)crystals with different morphologies by various synthetic methods.Furthermore,our review is mainly focused on the formation/etching mechanisms of{001}facets dominated anatase TiO_(2)crystals based on our and other studies.The extensive application potentials of the anatase TiO_(2)crystals with exposed{001}facets have been summarized in this review such as photocatalysis,photoelectrocatalysis,solar energy conversion,lithium ion battery,and hydrogen generation Based on the current studies,we give some perspectives on the research topic.We believe that this comprehensive review on anatase TiO_(2)crystals with high reactive{001}facets can further promote the relative research in this field.展开更多
TiO_(2)nanosheets with dominant{001}facets,coupled with Cs_(2.5)H_(0.5)PW_(12)O_(40),were successfully synthesized by a one-step hydrothermal reaction.The photocatalytic activity of nanocatalysts was evaluated by the ...TiO_(2)nanosheets with dominant{001}facets,coupled with Cs_(2.5)H_(0.5)PW_(12)O_(40),were successfully synthesized by a one-step hydrothermal reaction.The photocatalytic activity of nanocatalysts was evaluated by the degradation of Rhodamine B under UV light irradiation.The results showed that both the addition of Cs_(2.5)H_(0.5)PW_(12)O_(40)and the exposed{001}facets of TiO_(2)have a positive effect on the photocatalytic activity.The improved photoactivity of nanocomposites in comparison with that of TiO_(2)nanosheets could be attributed to the synergistic effect between Cs_(2.5)H_(0.5)PW_(12)O_(40)and TiO_(2)which facilitates the separation of photo-induced hole-electron pairs.展开更多
TiO_(2) nanosheets with highly reactive{001}facets({001}-TiO_(2))have attracted great attention in the fields of science and technology because of their unique properties.In recent years,many efforts have been made to...TiO_(2) nanosheets with highly reactive{001}facets({001}-TiO_(2))have attracted great attention in the fields of science and technology because of their unique properties.In recent years,many efforts have been made to synthesize{001}-TiO_(2) and to explore their applications in photocatalysis.In this review,we summarize the recent progress in preparing{001}-TiO_(2) using different techniques such as hydrothermal,solvothermal,alcohothermal,chemical vapor deposition(CVD),and sol gel-based techniques.Furthermore,the enhanced efficiency of{001}-TiO_(2) by modification of carbon materials,surface deposition of transition metals,and non-metal doping is reviewed.Then,the applications of{001}-TiOR-based photocatalysts in the degradation of organic dyes,hydrogen evolution,carbon dioxide(CO_(2))reduction,bacterial disinfection,and dye-sensitized solar cells are summarized.We believe this entire review on TiO_(2) nanosheets with{001}facets can further inspire researchers in associated fields.展开更多
Tailored synthesis of well-defined anatase TiO_(2)-based crystals with exposed{001}facets has stimulated incessant research interest worldwide due to their scientific and technological importance.Herein,anatase nitrog...Tailored synthesis of well-defined anatase TiO_(2)-based crystals with exposed{001}facets has stimulated incessant research interest worldwide due to their scientific and technological importance.Herein,anatase nitrogen-doped TiO_(2)(N-TiO_(2))nanoparticles with exposed{001}facets deposited on the graphene(GR)sheets(N-TiO_(2)-001/GR)were synthesized for the first time via a one-step solvothermal synthetic route using NH4F as the morphology-controlling agent.The experimental results exemplified that GR was uniformly covered with anatase N-TiO_(2) nanoparticles(10-17 nm),exposing the{001}facets.The percentage of exposed{001}facets in the N-TiO_(2)-001/GR nanocomposites was calculated to be ca.35%.Also,a red shift in the absorption edge and a strong absorption in the visible light range were observed due to the formation of Ti-O-C bonds,resulting in the successful narrowing of the band gap from 3.23 to 2.9 eV.The photocatalytic activities of the as-prepared photocatalysts were evaluated for CO_(2) reduction to produce CH,in the presence of water vapor under ambient temperature and atmospheric pressure using a low-power 15 W energy-saving daylight lamp as the visible light source--in contrast to the most commonly employed high-power xenon lamps--which rendered the process economically and practically feasible.Among all the studied photocatalysts,the N-TiO_(2)-001/GR nanocomposites exhibited the greatest CH4 yield of 3.70 p-mol'gcatalyst 1,approxi-mately 11-fold higher activity than the TiO_(2)-001.The enhancement of photocatalyfic performance was ascribed to the effective charge anti-recombination of graphene,high absorption of visible light region relative to the{101}facets.and high catalytic activity of{001}facets.展开更多
Photocatalytic carbon dioxide reduction reaction(CO_(2)RR)has been considered as one of most effective ways to solve the current energy crisis and environmental problems.However,the practical application of photocatal...Photocatalytic carbon dioxide reduction reaction(CO_(2)RR)has been considered as one of most effective ways to solve the current energy crisis and environmental problems.However,the practical application of photocatalytic CO_(2)RR is largely hindered by lock of efficient catalyst.Here,hierarchical titanium dioxide(TiO_(2))nanostructures with a highly active{001}surface were successfully synthesized by a facile approach from metal Ti powders.The obtained hierarchical TiO_(2)nanostructures were composed of TiO_(2)nanorods,which have a diameter about 5–10 nm and a length of several micrometers.It is found that these nanorods have exposed{001}facets.On the other hand,these hierarchical TiO_(2)nanostructures have a good light-harvesting efficiency with the help of TiO_(2)nanorods component and large specific surface area.Therefore,these hierarchical TiO_(2)nanostructures exhibit a much better activity for photocatalytic CO_(2)reduction than that of commercial TiO_(2)(P25).This high activity can be attributed to the synergistic effects of active surface,efficient charge transfer along nanorods and good light harvesting in the nanorod-hierarchical nanostructures.展开更多
The exposed crystal facet of TiO_(2) is a crucial factor influencing the gas sensing properties.TiO_(2) with high-energy{001}crystal facets that have higher surface energy and reactivity is expected to exhibit excelle...The exposed crystal facet of TiO_(2) is a crucial factor influencing the gas sensing properties.TiO_(2) with high-energy{001}crystal facets that have higher surface energy and reactivity is expected to exhibit excellent gas-sensing properties.In this paper,TiO_(2) nanoplates with defective{001}facets were synthesized by chemical etching via one-step hydrothermal method.We carefully explored the gas-sensing performance of TiO_(2) nanoplates with defective and complete{001}facets towards acetone.The results show that the sensing response of TiO_(2) nanoplates with complete{001}facets is 70%higher than that of defective TiO_(2) nanoplates,which proves that the{001}facets plays a vital role in improving the gas sensing performance of TiO_(2).It is speculated that the poor gas sensitivity of defective TiO_(2) can be contributed to fewer adsorption sites and blocked electron transfer.This work presents a more direct evidence for explaining the important role of the complete{001}crystal facets in high sensitivity of TiO_(2) and also provides a new insight for preparing high sensitivity sensing materials.展开更多
文摘Ultrathin TiO_(2)nanosheets with coexposed{001}/{101}facets have attracted considerable attention because of their high photocatalytic activity.However,the charge-separated states in the TiO_(2)nanosheets must be extended to further enhance their photocatalytic activity for H_(2)evolution.Herein,we present a successful attempt to selectively dope lanthanide ions into the{101}facets of ultrathin TiO_(2)nanosheets with coexposed{001}/{101}facets through a facile one-step solvothermal method.The lanthanide doping slightly extended the light-harvesting region and markedly improved the charge-separated states of the TiO_(2)nanosheets as evidenced by UV-vis absorption and steady-state/transient photoluminescence spectra.Upon simulated sunlight irradiation,we observed a 4.2-fold enhancement in the photocatalytic H_(2)evolution activity of optimal Yb^(3+)-doped TiO_(2)nanosheets compared to that of their undoped counterparts.Furthermore,when Pt nanoparticles were used as cocatalysts to reduce the H_(2)overpotential in this system,the photocatalytic activity enhancement factor increased to 8.5.By combining these results with those of control experiments,we confirmed that the extended charge-separated states play the main role in the enhancement of the photocatalytic H_(2)evolution activity of lanthanide-doped TiO_(2)nanosheets with coexposed{001}/{101}facets.
基金This work is supported by the National Basic Research Program of China(No.2012CB9222000).
文摘{001}facets dominated single crystalline anatase TiO_(2) nanosheet array(TNSA)was synthe-sized through an optimized organic solvothermal route on uorine-doped tin oxide substrate.The field emission scanning electron microscopy images and X-ray diffraction patterns re-vealed that the{001}synthesized facets dominated TNSA exhibited much higher orientation than that synthesized by hydrothermal route.The TNSAs were loaded with Pt nanoparti-cles in uniformly size by using a photodecomposition method,which were further con rmed by high resolution transmission electron microscopy(HRTEM).The HRTEM images also revealed that Pt nanoparticles preferred to deposit on{001}facets.With loading of Pt nanoparticles,the optical absorbance was significantly enhanced,while the photolumines-cence(PL)was inhibited.The photocatalytic activity of TNSA was signi cantly improved by Pt loading and reached the maximum with optimal amount of Pt loading.The optimal amount of Pt on{001}facets is far less than that on TiO_(2) nanoparticles,which may be attributed to the specific atom structure of reactive{001}facets.
基金financially supported by the Programs of Japan Science and Technology Agency:Promoting Individual Research to Nature the Seeds of Future Innovation and Organizing the Unique and Innovative Network,and Advanced Catalytic Transformation Program for Carbon Utilization
文摘Anatase titanium(IV)oxide(TiO_(2))particles with exposed{001}and{101}facets were prepared by hydrothermal treatment of amorphous TiO_(2) with H_(2)O_(2)-NH_(3) solution.Crystal phase,shape,and size of TiO_(2) particles are found to be greatly dependent on the ratio of H_(2)O_(2)-NH_(3) solution.The prepared TiO_(2) particles with specific exposed crystal faces show higher photocatalytic activity for acetaldehyde decomposition than commercial spherical TiO_(2) particles.This result implies that recombination is prevented by spatial separation of redox sites in the particles because of selective migration of electrons and positive holes to specific exposed crystal faces and/or different reactivity of electrons and positive holes on the specific exposed crystal face.
基金supported by Australian Research Council(ARC)Discovery Project
文摘Controllable growth of anatase TiO_(2)crystals with exposed high reactive crystal facets has aroused great attention in the fields of science and technology due to their unique structure-dependent properties.Recently,much effort has been paid to synthesize anatase TiO_(2)crystals with exposed high reactive{001}facets.Herein,we review the recent progress in synthesizing{001}facets dominated anatase TiO_(2)crystals with different morphologies by various synthetic methods.Furthermore,our review is mainly focused on the formation/etching mechanisms of{001}facets dominated anatase TiO_(2)crystals based on our and other studies.The extensive application potentials of the anatase TiO_(2)crystals with exposed{001}facets have been summarized in this review such as photocatalysis,photoelectrocatalysis,solar energy conversion,lithium ion battery,and hydrogen generation Based on the current studies,we give some perspectives on the research topic.We believe that this comprehensive review on anatase TiO_(2)crystals with high reactive{001}facets can further promote the relative research in this field.
基金This work was supported by the National Natural Science Foundation of China(Nos.21371035,21173050).
文摘TiO_(2)nanosheets with dominant{001}facets,coupled with Cs_(2.5)H_(0.5)PW_(12)O_(40),were successfully synthesized by a one-step hydrothermal reaction.The photocatalytic activity of nanocatalysts was evaluated by the degradation of Rhodamine B under UV light irradiation.The results showed that both the addition of Cs_(2.5)H_(0.5)PW_(12)O_(40)and the exposed{001}facets of TiO_(2)have a positive effect on the photocatalytic activity.The improved photoactivity of nanocomposites in comparison with that of TiO_(2)nanosheets could be attributed to the synergistic effect between Cs_(2.5)H_(0.5)PW_(12)O_(40)and TiO_(2)which facilitates the separation of photo-induced hole-electron pairs.
基金This work was supported by the National Basic Research Program of China(No.2013CB632402)the National Natural Science Foundation of China(Nos.51272199,51320105001,51372190,and 21433007)+4 种基金Also,this work was financially supported by the Natural Science Foundation of Hubei Province of China(Nos.2015CFA001 and 2014CFB164)Deanship of Scientific Research(DSR)of King Abdulaziz University(No.90-130-35-HiCi)the Fundamental Research Funds for the Central Universities(Nos.WUT:2014-VII-010,2014-IV-058,2014-IV-155)Self-determined and Innova-tive Research Funds of SKLWUT(No.2013-ZD-1)a WUT Start-Up Grant.
文摘TiO_(2) nanosheets with highly reactive{001}facets({001}-TiO_(2))have attracted great attention in the fields of science and technology because of their unique properties.In recent years,many efforts have been made to synthesize{001}-TiO_(2) and to explore their applications in photocatalysis.In this review,we summarize the recent progress in preparing{001}-TiO_(2) using different techniques such as hydrothermal,solvothermal,alcohothermal,chemical vapor deposition(CVD),and sol gel-based techniques.Furthermore,the enhanced efficiency of{001}-TiO_(2) by modification of carbon materials,surface deposition of transition metals,and non-metal doping is reviewed.Then,the applications of{001}-TiOR-based photocatalysts in the degradation of organic dyes,hydrogen evolution,carbon dioxide(CO_(2))reduction,bacterial disinfection,and dye-sensitized solar cells are summarized.We believe this entire review on TiO_(2) nanosheets with{001}facets can further inspire researchers in associated fields.
文摘Tailored synthesis of well-defined anatase TiO_(2)-based crystals with exposed{001}facets has stimulated incessant research interest worldwide due to their scientific and technological importance.Herein,anatase nitrogen-doped TiO_(2)(N-TiO_(2))nanoparticles with exposed{001}facets deposited on the graphene(GR)sheets(N-TiO_(2)-001/GR)were synthesized for the first time via a one-step solvothermal synthetic route using NH4F as the morphology-controlling agent.The experimental results exemplified that GR was uniformly covered with anatase N-TiO_(2) nanoparticles(10-17 nm),exposing the{001}facets.The percentage of exposed{001}facets in the N-TiO_(2)-001/GR nanocomposites was calculated to be ca.35%.Also,a red shift in the absorption edge and a strong absorption in the visible light range were observed due to the formation of Ti-O-C bonds,resulting in the successful narrowing of the band gap from 3.23 to 2.9 eV.The photocatalytic activities of the as-prepared photocatalysts were evaluated for CO_(2) reduction to produce CH,in the presence of water vapor under ambient temperature and atmospheric pressure using a low-power 15 W energy-saving daylight lamp as the visible light source--in contrast to the most commonly employed high-power xenon lamps--which rendered the process economically and practically feasible.Among all the studied photocatalysts,the N-TiO_(2)-001/GR nanocomposites exhibited the greatest CH4 yield of 3.70 p-mol'gcatalyst 1,approxi-mately 11-fold higher activity than the TiO_(2)-001.The enhancement of photocatalyfic performance was ascribed to the effective charge anti-recombination of graphene,high absorption of visible light region relative to the{101}facets.and high catalytic activity of{001}facets.
基金Project(21872174)supported by the National Natural Science Foundation of ChinaProjects(2017CX003,20180018050001)supported by the Innovation-Driven Plan in Central South University,China+3 种基金Project supported by State Key Laboratory of Powder Metallurgy in Central South University,ChinaProject(JCYJ20180307151313532)supported by Shenzhen Science and Technology Innovation Project,ChinaProject supported by the Thousand Youth Talents Plan of ChinaProject supported by the Hundred Youth Talents Program of Hunan,China
文摘Photocatalytic carbon dioxide reduction reaction(CO_(2)RR)has been considered as one of most effective ways to solve the current energy crisis and environmental problems.However,the practical application of photocatalytic CO_(2)RR is largely hindered by lock of efficient catalyst.Here,hierarchical titanium dioxide(TiO_(2))nanostructures with a highly active{001}surface were successfully synthesized by a facile approach from metal Ti powders.The obtained hierarchical TiO_(2)nanostructures were composed of TiO_(2)nanorods,which have a diameter about 5–10 nm and a length of several micrometers.It is found that these nanorods have exposed{001}facets.On the other hand,these hierarchical TiO_(2)nanostructures have a good light-harvesting efficiency with the help of TiO_(2)nanorods component and large specific surface area.Therefore,these hierarchical TiO_(2)nanostructures exhibit a much better activity for photocatalytic CO_(2)reduction than that of commercial TiO_(2)(P25).This high activity can be attributed to the synergistic effects of active surface,efficient charge transfer along nanorods and good light harvesting in the nanorod-hierarchical nanostructures.
基金financially supported by the National Natural Science Foundation of China(Nos.51773226,61701514)the Natural Science Foundation of Hunan Province(No.2018JJ3603)
文摘The exposed crystal facet of TiO_(2) is a crucial factor influencing the gas sensing properties.TiO_(2) with high-energy{001}crystal facets that have higher surface energy and reactivity is expected to exhibit excellent gas-sensing properties.In this paper,TiO_(2) nanoplates with defective{001}facets were synthesized by chemical etching via one-step hydrothermal method.We carefully explored the gas-sensing performance of TiO_(2) nanoplates with defective and complete{001}facets towards acetone.The results show that the sensing response of TiO_(2) nanoplates with complete{001}facets is 70%higher than that of defective TiO_(2) nanoplates,which proves that the{001}facets plays a vital role in improving the gas sensing performance of TiO_(2).It is speculated that the poor gas sensitivity of defective TiO_(2) can be contributed to fewer adsorption sites and blocked electron transfer.This work presents a more direct evidence for explaining the important role of the complete{001}crystal facets in high sensitivity of TiO_(2) and also provides a new insight for preparing high sensitivity sensing materials.
