Magnéli phases Ti_nO_(2n-1)have been demonstrated as promising environmentally friendly materials in advanced oxidation processes.In this study,Magnéli phases Ti_nO_(2n-1)have been used as catalysts for the ...Magnéli phases Ti_nO_(2n-1)have been demonstrated as promising environmentally friendly materials in advanced oxidation processes.In this study,Magnéli phases Ti_nO_(2n-1)have been used as catalysts for the ozonation of phenol in aqueous solution for the first time.The materials exhibited excellent catalytic ozonation activities both in phenol degradation and mineralization.When Ti_4O_7was added,the reaction rate was six-fold higher than that of with ozone alone,while the total organic carbon removal rate was substantially elevated from around 19.2%to 92%.By virtue of the good chemical stability of the materials,a low metal leaching of less than 0.15 mg·L^(-1)could effectively avoid the secondary pollution by metal ions.Radical quenching tests revealed·O_2^-and^1O_2to be active oxygen species for phenol degradation at p H 5.As semiconductor catalysts,Ti_nO_(2n-1)materials show electronic transfer capability.Ozone adsorbed at B-acid sites of the catalyst surface can capture an electron from the conversion of Ti(III)to Ti(IV),and is thereby broken into the active oxygen species.It was interesting to observe that Ti_nO_(2n-1)exhibit better catalytic activity for phenol degradation and mineralization with lower n value.The difference in electrical conductivity can be considered as a major factor for the catalytic performances.More highly conductive catalysts show a faster electron-transfer rate and better catalytic activity.Thus,significant evidences have been obtained for a single-electron-transfer mechanism of catalytic ozonation with Magnéli phases Ti_nO_(2n-1).展开更多
基金Supported by the National Natural Science Foundation of China(21676139)the Higher Education Natural Science Foundation of Jiangsu Province(15KJA530001)+1 种基金the Project of Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)the Research Fund of State Key Laboratory of MaterialsOriented Chemical Engineering(ZK201604)
文摘Magnéli phases Ti_nO_(2n-1)have been demonstrated as promising environmentally friendly materials in advanced oxidation processes.In this study,Magnéli phases Ti_nO_(2n-1)have been used as catalysts for the ozonation of phenol in aqueous solution for the first time.The materials exhibited excellent catalytic ozonation activities both in phenol degradation and mineralization.When Ti_4O_7was added,the reaction rate was six-fold higher than that of with ozone alone,while the total organic carbon removal rate was substantially elevated from around 19.2%to 92%.By virtue of the good chemical stability of the materials,a low metal leaching of less than 0.15 mg·L^(-1)could effectively avoid the secondary pollution by metal ions.Radical quenching tests revealed·O_2^-and^1O_2to be active oxygen species for phenol degradation at p H 5.As semiconductor catalysts,Ti_nO_(2n-1)materials show electronic transfer capability.Ozone adsorbed at B-acid sites of the catalyst surface can capture an electron from the conversion of Ti(III)to Ti(IV),and is thereby broken into the active oxygen species.It was interesting to observe that Ti_nO_(2n-1)exhibit better catalytic activity for phenol degradation and mineralization with lower n value.The difference in electrical conductivity can be considered as a major factor for the catalytic performances.More highly conductive catalysts show a faster electron-transfer rate and better catalytic activity.Thus,significant evidences have been obtained for a single-electron-transfer mechanism of catalytic ozonation with Magnéli phases Ti_nO_(2n-1).
