Nitrogen-doped HTiNbO5 nanosheets have been successfully synthesized by first exfoliating layered HTiNbO5 in tetrabutylammonium hydroxide （TBAOH） to obtain HTiNbO5 nanosheets and then heating the nanosheets with ure...Nitrogen-doped HTiNbO5 nanosheets have been successfully synthesized by first exfoliating layered HTiNbO5 in tetrabutylammonium hydroxide （TBAOH） to obtain HTiNbO5 nanosheets and then heating the nanosheets with urea. The resulting samples were characterized by X-ray diffraction （XRD）, transmission electron microscopy （TEM）, scanning electron microscopy （SEM）, energy-dispersive X-ray （EDX）, X-ray photoelectron spectroscopy （XPS）, UV-vis spectroscopy and N2 adsorption-desorption measurements. It was found that N-doping resulted in a much higher thermostability of the layered structure, intrinsic bandgap narrowing and a visible light response. The doped nitrogen atoms were mainly located in the interstitial sites of TiNbOs- lamellae and chemically bound to hydrogen ions. Compared with N-doped HTiNbOs, N-doped HTiNbO5 nanosheets had a much larger specific surface area and richer mesoporosity due to fee rather loose and irregular arrangement of fitanoniobate nanosheets. Both N-doped layered HTiNbOs and HTiNbO5 nanosheets showed a very high visible-light photocatalytic activity for the degradation of rhodamine B （RhB） aqueous solution. Moreover, due to the considerably larger surface area, richer mesoporosity and stronger acidity, N-doped HTiNbO5 nanosheets had an even higher activity than N-doped HTiNbOs, although the latter had a stronger absorption in the visible region. The dye molecules were mainly degraded to aliphatic organic compounds and partially mineralized to CO2 and/or CO, rather than being simply decolorized. The effect of photosensitization was insignificant and RhB was degraded mainly via the typical photocatalytic reaction routes. Two different reaction routes for the photodegradation of RhB under visible light irradiation over N-doped HTiNbO5 nanosheets have been proposed. The present method can be extended to a large number of layered metal oxides that have the characteristics of intercalation and exfoliation, thus providing new opportunities for the fabrication of highly展开更多
A series of alumina-pillared layered titanoniobates with different interlayer distances were first prepared by using a step-wise exchange process. The effect of reaction conditions such as reaction temperature, reacti...A series of alumina-pillared layered titanoniobates with different interlayer distances were first prepared by using a step-wise exchange process. The effect of reaction conditions such as reaction temperature, reaction time, ageing time of pillaring agent, and molar ratio of two reactans was exmained. The resultat pillazed smples have a range of interlayer distances from 1.23 nm to 1.38nm, and are thermostable over 500展开更多
剥离–重堆积法制备的α-Fe2O3/HTi Nb O5柱撑复合材料呈介孔结构,比表面积达140 m2·g–1。当α-Fe2O3∶HTi Nb O5摩尔比为1∶2时,在可见光照射下,复合材料催化降解罗丹明B的效率达38%,分别是HTi Nb O5和Fe2O3的3.2倍和1.7倍。复...剥离–重堆积法制备的α-Fe2O3/HTi Nb O5柱撑复合材料呈介孔结构,比表面积达140 m2·g–1。当α-Fe2O3∶HTi Nb O5摩尔比为1∶2时,在可见光照射下,复合材料催化降解罗丹明B的效率达38%,分别是HTi Nb O5和Fe2O3的3.2倍和1.7倍。复合材料的高光催化活性主要来自于HTi Nb O5主体与α-Fe2O3客体间形成的异质结,使材料吸收边红移至可见光区,改善了光生载流子的分离效率,从而提高了材料的光催化活性。展开更多
基金Acknowledgements The authors greatly appreciate the financial support of the National Natural Science Foundation of China （Grant Nos. 21073084 and 20773065）, the National Basic Research Program （973 Project） （Grant No. 2007CB936302） and the Modern Analysis Center of Nanjing University.
文摘Nitrogen-doped HTiNbO5 nanosheets have been successfully synthesized by first exfoliating layered HTiNbO5 in tetrabutylammonium hydroxide （TBAOH） to obtain HTiNbO5 nanosheets and then heating the nanosheets with urea. The resulting samples were characterized by X-ray diffraction （XRD）, transmission electron microscopy （TEM）, scanning electron microscopy （SEM）, energy-dispersive X-ray （EDX）, X-ray photoelectron spectroscopy （XPS）, UV-vis spectroscopy and N2 adsorption-desorption measurements. It was found that N-doping resulted in a much higher thermostability of the layered structure, intrinsic bandgap narrowing and a visible light response. The doped nitrogen atoms were mainly located in the interstitial sites of TiNbOs- lamellae and chemically bound to hydrogen ions. Compared with N-doped HTiNbOs, N-doped HTiNbO5 nanosheets had a much larger specific surface area and richer mesoporosity due to fee rather loose and irregular arrangement of fitanoniobate nanosheets. Both N-doped layered HTiNbOs and HTiNbO5 nanosheets showed a very high visible-light photocatalytic activity for the degradation of rhodamine B （RhB） aqueous solution. Moreover, due to the considerably larger surface area, richer mesoporosity and stronger acidity, N-doped HTiNbO5 nanosheets had an even higher activity than N-doped HTiNbOs, although the latter had a stronger absorption in the visible region. The dye molecules were mainly degraded to aliphatic organic compounds and partially mineralized to CO2 and/or CO, rather than being simply decolorized. The effect of photosensitization was insignificant and RhB was degraded mainly via the typical photocatalytic reaction routes. Two different reaction routes for the photodegradation of RhB under visible light irradiation over N-doped HTiNbO5 nanosheets have been proposed. The present method can be extended to a large number of layered metal oxides that have the characteristics of intercalation and exfoliation, thus providing new opportunities for the fabrication of highly
文摘A series of alumina-pillared layered titanoniobates with different interlayer distances were first prepared by using a step-wise exchange process. The effect of reaction conditions such as reaction temperature, reaction time, ageing time of pillaring agent, and molar ratio of two reactans was exmained. The resultat pillazed smples have a range of interlayer distances from 1.23 nm to 1.38nm, and are thermostable over 500
基金supported by the National Basic Research Program of China (973 Program, 2009CB623504)the National Natural Science Foundation of China (21073084, 20773065)the National Science Fund for Talent Training in Basic Science (J1103310)~~
文摘剥离–重堆积法制备的α-Fe2O3/HTi Nb O5柱撑复合材料呈介孔结构,比表面积达140 m2·g–1。当α-Fe2O3∶HTi Nb O5摩尔比为1∶2时,在可见光照射下,复合材料催化降解罗丹明B的效率达38%,分别是HTi Nb O5和Fe2O3的3.2倍和1.7倍。复合材料的高光催化活性主要来自于HTi Nb O5主体与α-Fe2O3客体间形成的异质结,使材料吸收边红移至可见光区,改善了光生载流子的分离效率,从而提高了材料的光催化活性。
