In this work,highly regular TiO_(2)nanorod array films were synthesized in situ on FTO by a facile hydrothermal method,and then ZnO shell layers were grown on the surface of the nanorods to form a coreshell structure ...In this work,highly regular TiO_(2)nanorod array films were synthesized in situ on FTO by a facile hydrothermal method,and then ZnO shell layers were grown on the surface of the nanorods to form a coreshell structure via an ion-layer adsorption-reaction way.Compared to the TiO_(2)nanorods,the prepared TiO_(2)/ZnO nanocomposites exhibited enhanced ethanol sensing performances,including a low working temperature,higher sensitivity,and faster response capability.The optimum sensor based on 2c-TiO_(2)/ZnO exhibited the maximum response value of 30.85 toward 50×10^(-6)C_(2)H_(5)OH at 340℃,which was almost 4.15 times higher than that of the TiO_(2)sensor.The improved ethanol sensing mechanism was discussed in relation to the unique nanorod array structure and the heterojunctions between TiO_(2)and ZnO.展开更多
Light capture and electron recombination are the essential processes that determine power conversion efficiency （PCE） in quantum dot sensitized solar cells （QD- SCs）. It is well known that charges are easily trans...Light capture and electron recombination are the essential processes that determine power conversion efficiency （PCE） in quantum dot sensitized solar cells （QD- SCs）. It is well known that charges are easily transported in well-built QDSCs based on nauorod arrays. However, this advantage can be drastically weakened by defects located at the zinc oxide （ZnO） array surface which permit faster electron recombination. Hence, we developed a composite nanostructure consisting of ZnO nanorods coated with orthorhombic configuration titanium dioxide （TiO2） nanopartides, which were synthesized using a solution of H3BO3 and （NH4）2TiF6. This composite nanostructure was designed to take the advantage of the enlarged surface area provided by the nanoparticles and improved electron transport along the nanorods, in order to yield good charge transport and light harvesting. At the same time, the TiO2/ZnO nanorod arrays have fewer recombination centers （hydroxyl groups） after TiO2 modification, which results in fewer electron trapping events at the ZnO nanorod surface; thereby, a reduced charge recombination and longer electron lifetime can be achieved. As a result, the PCE of the QDSCs with TiO2-nanopartides-decorated ZnO nanorod arrays photoelectrode reaches 4.8%, which is ～78% higher efficiency compared to 2.7% for solar cells without modification.展开更多
基金the Youth Project of Henan Natural Science Foundation(212300410149)the National Natural Science Foundation of China(62101177)the Key Scientific Research Project of Colleges and University in Henan Province(21A430019).
文摘In this work,highly regular TiO_(2)nanorod array films were synthesized in situ on FTO by a facile hydrothermal method,and then ZnO shell layers were grown on the surface of the nanorods to form a coreshell structure via an ion-layer adsorption-reaction way.Compared to the TiO_(2)nanorods,the prepared TiO_(2)/ZnO nanocomposites exhibited enhanced ethanol sensing performances,including a low working temperature,higher sensitivity,and faster response capability.The optimum sensor based on 2c-TiO_(2)/ZnO exhibited the maximum response value of 30.85 toward 50×10^(-6)C_(2)H_(5)OH at 340℃,which was almost 4.15 times higher than that of the TiO_(2)sensor.The improved ethanol sensing mechanism was discussed in relation to the unique nanorod array structure and the heterojunctions between TiO_(2)and ZnO.
基金supported by the National Natural Science Foundation of China(51362026)the Technological Innovation Youth Training Project of Xinjiang Uyghur Autonomous Region of China(QN2015YX004)+1 种基金Qun Jing would like to acknowledge the support from the Foundation for High-level Talents in Shihezi University(RCZX201511)the Applied Basic Research Foundation of Science and Technology in Shihezi University(2015ZRKXYQ07)
文摘Light capture and electron recombination are the essential processes that determine power conversion efficiency （PCE） in quantum dot sensitized solar cells （QD- SCs）. It is well known that charges are easily transported in well-built QDSCs based on nauorod arrays. However, this advantage can be drastically weakened by defects located at the zinc oxide （ZnO） array surface which permit faster electron recombination. Hence, we developed a composite nanostructure consisting of ZnO nanorods coated with orthorhombic configuration titanium dioxide （TiO2） nanopartides, which were synthesized using a solution of H3BO3 and （NH4）2TiF6. This composite nanostructure was designed to take the advantage of the enlarged surface area provided by the nanoparticles and improved electron transport along the nanorods, in order to yield good charge transport and light harvesting. At the same time, the TiO2/ZnO nanorod arrays have fewer recombination centers （hydroxyl groups） after TiO2 modification, which results in fewer electron trapping events at the ZnO nanorod surface; thereby, a reduced charge recombination and longer electron lifetime can be achieved. As a result, the PCE of the QDSCs with TiO2-nanopartides-decorated ZnO nanorod arrays photoelectrode reaches 4.8%, which is ～78% higher efficiency compared to 2.7% for solar cells without modification.
