Titanium suboxide is an excellent electrode material for many oxidization reactions.In this article,the electrodes of pure Ti_4O_7,doped Ti_4O_7and the mixed-crystal of Ti_4O_7and Ti_5O_9were prepared to evaluate thei...Titanium suboxide is an excellent electrode material for many oxidization reactions.In this article,the electrodes of pure Ti_4O_7,doped Ti_4O_7and the mixed-crystal of Ti_4O_7and Ti_5O_9were prepared to evaluate their activities and doping effects in the electro-degradation of phenol.It was revealed by the HPLC analysis results that the degradation intermediates and routes were significantly affected by the doping element.On the pure Ti_4O_7anode,a series of classic intermediates were obtained from benzoquinone and hydroquinone to various carboxylic acids.These intermediates were degraded gradually to the final organic intermediate of oxalate in all experiments.At last,oxalate was oxidized to CO_2and H_2O.Distinctively,the Y-doped Ti_4O_7 anode directly broke phenol toα-ketoglutaric acid without the intermediates of benzoquinone and hydroquinone.The strong oxidization ability of the Y-doped Ti_4O_7 anode might be responsible for the highest COD removal ratio.In contrast,the Ga-doped Ti_4O_7 anode showed the worst degradation activity in this article.Three intermediates of benzoquinone,hydroquinone and maleic acid were found during the degradation.Benefiting from the weak ability,oxalate was efficiently accumulated with a very high yield of 74.6%.The results demonstrated promising applications from electrochemical preparation to wastewater degradation by adjusting the doping reagent of Ti_4O_7 electrodes.展开更多
Flow anodic oxidation system has demonstrated to be a promising and environmental benign water treatment technology because of its advantages of high contaminant removal efficiency and low energy consumption.However,t...Flow anodic oxidation system has demonstrated to be a promising and environmental benign water treatment technology because of its advantages of high contaminant removal efficiency and low energy consumption.However,traditional setup needs an external unit for flow anode material separation and recovery,which inevitably increases the capital cost and hinders its continuous operation.Herein,a specific porous cathode is introduced to achieve continuous water purification with high contaminant removal in a flow anodic oxidation system.The efuent concentration of carbamazepine(CBZ),a common and model contaminant widely detected in natural water environment,was reduced by 99%.The linear sweep voltammetry(LSV)and quenching tests demonstrated that HO·was the dominant reactive species.While the removal of contaminants was inhibited in practical surface water,largely related to the quenching by dissolved organic matter and bicarbonate,the flow anodic oxidation process was competent in alleviating the ecotoxicity following oxidation.Our study constructs a modular device for cost-effective continuous water purification and provides insight into the mechanisms of flow andic oxidation.展开更多
The n-type semiconducting titanium oxide thin films are well-known as electron transporting interlayer in photovoltaic cells.The favorable characteristics of interlayers in photovoltaics are high optical transmittance...The n-type semiconducting titanium oxide thin films are well-known as electron transporting interlayer in photovoltaic cells.The favorable characteristics of interlayers in photovoltaics are high optical transmittance(T%),wide band gap energy(Eg)and high electrical conductivity(σ).Modifying titanium oxide films with metal nanoparticles would increase electrical conductivity but reduce optical band gap energy.We developed the sol-gel derived titanium suboxide(TiOx)films modified with silver(Ag)or gold(Au)or copper(Cu)nanoparticles(NPs).This study explores a tradeoff between narrowing optical band gap and enhancing electrical conductivity of nanostructured TiOx films by controlling the Au-or Ag-or Cu-NPs loading concentrations(mol%)in titania.The Au-and Cu-NPs loading concentration of 4 mol%should meet a tradeoff which yields the higher T%,wider Eg and higher compared to those of pure TiOx films.In addition,since the pure Cu is not thermodynamically stable in ambience as compared to Au and Ag,the stability of as-obtained colloidal CuNPs is also examined.A careful examination of the time evolution of surface plasmon resonance(SPR)bands of CuNPs indicates that their stability is only up to 4 h.展开更多
Titanium suboxides,denoted as Ti_(n)O_(m)(O<m/n<2),represent a typical class of non-stoichiometric compounds characterized by a wide range of structures and physicochemical properties dependent on their variable...Titanium suboxides,denoted as Ti_(n)O_(m)(O<m/n<2),represent a typical class of non-stoichiometric compounds characterized by a wide range of structures and physicochemical properties dependent on their variable titanium-to-oxygen ratios.This review systematically summarizes the crystallographic features,electronic structures,physical properties,and energy-related applications of Ti_(n)O_(m).As oxygen atoms are progressively removed from TiO_(2),the emergence of Ti-Ti metallic bonds transforms the compound from a semiconductor to a metallic conductor.The diverse configurations of Ti 3d orbital electrons impart unique physical properties to Ti_(n)O_(m),including superconductivity,charge density waves,and ferromagnetism.This article provides an in-depth analysis of how various synthesis methods influence the crystal structures of the obtained Ti_(n)O_(m).Due to their distinct energy band structures and physical characteristics,titanium suboxides demonstrate outstanding performance in applications such as electrochemical energy storage,thermoelectric conversion,electronic devices,catalysis,and microwave absorption.This review not only comprehensively presents the fundamental structures and properties of titanium suboxides,but also offers valuable insights to guide future research in this field.展开更多
基金Supported by the Key Research Program of Frontier Sciences of CAS(No.QYZDJSSW-JSC021)the Science and Technology Cooperation for Yunnan Province and CAS(No.2016IB002)+1 种基金Science and Technology Service Network Initiative of CAS(No.KFJ-SWSTS-148)the National Natural Science Foundation of China(Nos.21506233,51402303,21606241,51374191)
文摘Titanium suboxide is an excellent electrode material for many oxidization reactions.In this article,the electrodes of pure Ti_4O_7,doped Ti_4O_7and the mixed-crystal of Ti_4O_7and Ti_5O_9were prepared to evaluate their activities and doping effects in the electro-degradation of phenol.It was revealed by the HPLC analysis results that the degradation intermediates and routes were significantly affected by the doping element.On the pure Ti_4O_7anode,a series of classic intermediates were obtained from benzoquinone and hydroquinone to various carboxylic acids.These intermediates were degraded gradually to the final organic intermediate of oxalate in all experiments.At last,oxalate was oxidized to CO_2and H_2O.Distinctively,the Y-doped Ti_4O_7 anode directly broke phenol toα-ketoglutaric acid without the intermediates of benzoquinone and hydroquinone.The strong oxidization ability of the Y-doped Ti_4O_7 anode might be responsible for the highest COD removal ratio.In contrast,the Ga-doped Ti_4O_7 anode showed the worst degradation activity in this article.Three intermediates of benzoquinone,hydroquinone and maleic acid were found during the degradation.Benefiting from the weak ability,oxalate was efficiently accumulated with a very high yield of 74.6%.The results demonstrated promising applications from electrochemical preparation to wastewater degradation by adjusting the doping reagent of Ti_4O_7 electrodes.
基金financially supported by the Basic Science Center Project of the National Natural Science Foundation of China(No.52388101)Program for Guangdong Introducing Innovative and Entrepreneurial Teams(No.2019ZT08L213)the National Natural Science Foundation of China(No.52100030)。
文摘Flow anodic oxidation system has demonstrated to be a promising and environmental benign water treatment technology because of its advantages of high contaminant removal efficiency and low energy consumption.However,traditional setup needs an external unit for flow anode material separation and recovery,which inevitably increases the capital cost and hinders its continuous operation.Herein,a specific porous cathode is introduced to achieve continuous water purification with high contaminant removal in a flow anodic oxidation system.The efuent concentration of carbamazepine(CBZ),a common and model contaminant widely detected in natural water environment,was reduced by 99%.The linear sweep voltammetry(LSV)and quenching tests demonstrated that HO·was the dominant reactive species.While the removal of contaminants was inhibited in practical surface water,largely related to the quenching by dissolved organic matter and bicarbonate,the flow anodic oxidation process was competent in alleviating the ecotoxicity following oxidation.Our study constructs a modular device for cost-effective continuous water purification and provides insight into the mechanisms of flow andic oxidation.
文摘The n-type semiconducting titanium oxide thin films are well-known as electron transporting interlayer in photovoltaic cells.The favorable characteristics of interlayers in photovoltaics are high optical transmittance(T%),wide band gap energy(Eg)and high electrical conductivity(σ).Modifying titanium oxide films with metal nanoparticles would increase electrical conductivity but reduce optical band gap energy.We developed the sol-gel derived titanium suboxide(TiOx)films modified with silver(Ag)or gold(Au)or copper(Cu)nanoparticles(NPs).This study explores a tradeoff between narrowing optical band gap and enhancing electrical conductivity of nanostructured TiOx films by controlling the Au-or Ag-or Cu-NPs loading concentrations(mol%)in titania.The Au-and Cu-NPs loading concentration of 4 mol%should meet a tradeoff which yields the higher T%,wider Eg and higher compared to those of pure TiOx films.In addition,since the pure Cu is not thermodynamically stable in ambience as compared to Au and Ag,the stability of as-obtained colloidal CuNPs is also examined.A careful examination of the time evolution of surface plasmon resonance(SPR)bands of CuNPs indicates that their stability is only up to 4 h.
基金supported by the National Natural Science Foundation of China(22471283 and 52202327)the Science and Technology Commission of Shanghai Municipality(23DZ1200800 and 22ZR1471300).
文摘Titanium suboxides,denoted as Ti_(n)O_(m)(O<m/n<2),represent a typical class of non-stoichiometric compounds characterized by a wide range of structures and physicochemical properties dependent on their variable titanium-to-oxygen ratios.This review systematically summarizes the crystallographic features,electronic structures,physical properties,and energy-related applications of Ti_(n)O_(m).As oxygen atoms are progressively removed from TiO_(2),the emergence of Ti-Ti metallic bonds transforms the compound from a semiconductor to a metallic conductor.The diverse configurations of Ti 3d orbital electrons impart unique physical properties to Ti_(n)O_(m),including superconductivity,charge density waves,and ferromagnetism.This article provides an in-depth analysis of how various synthesis methods influence the crystal structures of the obtained Ti_(n)O_(m).Due to their distinct energy band structures and physical characteristics,titanium suboxides demonstrate outstanding performance in applications such as electrochemical energy storage,thermoelectric conversion,electronic devices,catalysis,and microwave absorption.This review not only comprehensively presents the fundamental structures and properties of titanium suboxides,but also offers valuable insights to guide future research in this field.
