The use of TiO2 as an anode in rechargeable sodium-ion batteries(NIBs)is hampered by intrinsic low electronic conductivity of TiO2 and in ferior electrode kinetics.Here,a high-performa nee T1O2 electrode for NIBs is p...The use of TiO2 as an anode in rechargeable sodium-ion batteries(NIBs)is hampered by intrinsic low electronic conductivity of TiO2 and in ferior electrode kinetics.Here,a high-performa nee T1O2 electrode for NIBs is prese nted by desig ning a multicha rinel porous T1O2 nano fibers with well-dispersed Cu nan odots and Cu^2+-doping derived oxyge n vaca ncies(Cu-MPTO).The in-situ grow n well-dispersed copper nano dots of about 3 nm on TiO2 surface could significantly enhance electronic conductivity of the TiO2 fibers.The one-dimensional multichannel porous structure could facilitate the electrolyte to soak in,leadi ng to short tran sport path of Na^+through carb on toward the TiO2 nano particle.The Cu^2+-doping induced oxygen vacancies could decrease the bandgap of T1O2,resulting in easy electron trapping.With this strategy,the Cu-MPTO electrodes render an outstanding rate performance for NIBs(120 mAh·g^-1 at 20 C)and a superior cycling stability for ultralong cycle life(120 mAh·g^-1 at 20 C and 96.5%retention over 2,000 cycles).Density functional theory(DFT)calculations also suggest that Cu^2+doping can enhance the conductivity and electron transfer of T1O2 and lower the sodiation energy barrier.This strategy is confirmed to be a general process and could be extended to improve the performance of other materials with low electronic conductivity applied in energy storage systems.展开更多
Organic-inorganic hybrid perovskite solar cells (PSCs) are attracting tremendous attention for new-generation photovoltaic devices because of their excellent power conversion efficiency and simple fabrication process....Organic-inorganic hybrid perovskite solar cells (PSCs) are attracting tremendous attention for new-generation photovoltaic devices because of their excellent power conversion efficiency and simple fabrication process. One of the various approaches to increase the efficiency of PSCs is to change the material or structure of the carrier transport layer. Here, optically long and electrically short structural concept is proposed to enhance the characteristics of a PSC by employing selectively grown single crystalline TiO2 nanorods. The approach has the merit of increasing the electro n-hole separati on effectively and en ables a thicker active layer to be coated without electrical loss by using TiO2 nano rods as an electr on pathway. Moreover, selectively grow n TiO2 nano rods in crease the optical path of the in cide nt light via scatteri ng effects and en able a smooth coati ng of the active layer. Nano imprint lithography and hydrothermal growth were employed to fabricate selectively grow n TiO2 nanorod substrates. The fabricated solar cell exhibits an efficiency of 19.86% with a current density, open-circuit voltage, and fill factor of 23.13 mA/cm^2, 1.120 V, and 76.69%, respectively. Time-resolved photoluminescence, ultraviolet-visible (UV-Vis) spectroscopy, and the incident phot on to current efficiency (IPCE) an alysis were conducted to understand the factors resp on sible for the improvement in characteristics of the fabricated PSCs.展开更多
MC3T3-E1 osteoblasts were cultured on H2O2- modified and unmodified carbon/carbon （H-C/C and C/C） composites for one week in order to evaluate differences in cell adhesion, spreading, and proliferation. The results ...MC3T3-E1 osteoblasts were cultured on H2O2- modified and unmodified carbon/carbon （H-C/C and C/C） composites for one week in order to evaluate differences in cell adhesion, spreading, and proliferation. The results indicated a certain degree of enhancement in the cell adhesion capability of osteoblasts cultured on H-C/C samples. Cellu- lar morphologies after cell adhesion were observed via scan- ning electron microscopy （SEM）, which showed that the cells adhered more closely and spread more widely on the H-C/C sample surface. However, no cell appeared in several mul- tiple and continuous types of minor pores on both the C/C and H-C/C surfaces. In addition, two unique situations were observed on the H-C/C samples： an outline change of the osteoblasts was observed when the cells spread across some minor pores, and the cells entered and adhered well in some larger pores.展开更多
基金This work was supported by the National Key R&D Research Program of China(Nos.2018YFB0905400 and 2016YFB0100305)the National Natural Science Foundation of China(Nos.51622210 and 51872277)+1 种基金the Fundamental Research Funds for the Central Univers让ies(No.WK3430000004)the DNL cooperation Fund,CAS(No.DNL180310).
文摘The use of TiO2 as an anode in rechargeable sodium-ion batteries(NIBs)is hampered by intrinsic low electronic conductivity of TiO2 and in ferior electrode kinetics.Here,a high-performa nee T1O2 electrode for NIBs is prese nted by desig ning a multicha rinel porous T1O2 nano fibers with well-dispersed Cu nan odots and Cu^2+-doping derived oxyge n vaca ncies(Cu-MPTO).The in-situ grow n well-dispersed copper nano dots of about 3 nm on TiO2 surface could significantly enhance electronic conductivity of the TiO2 fibers.The one-dimensional multichannel porous structure could facilitate the electrolyte to soak in,leadi ng to short tran sport path of Na^+through carb on toward the TiO2 nano particle.The Cu^2+-doping induced oxygen vacancies could decrease the bandgap of T1O2,resulting in easy electron trapping.With this strategy,the Cu-MPTO electrodes render an outstanding rate performance for NIBs(120 mAh·g^-1 at 20 C)and a superior cycling stability for ultralong cycle life(120 mAh·g^-1 at 20 C and 96.5%retention over 2,000 cycles).Density functional theory(DFT)calculations also suggest that Cu^2+doping can enhance the conductivity and electron transfer of T1O2 and lower the sodiation energy barrier.This strategy is confirmed to be a general process and could be extended to improve the performance of other materials with low electronic conductivity applied in energy storage systems.
文摘Organic-inorganic hybrid perovskite solar cells (PSCs) are attracting tremendous attention for new-generation photovoltaic devices because of their excellent power conversion efficiency and simple fabrication process. One of the various approaches to increase the efficiency of PSCs is to change the material or structure of the carrier transport layer. Here, optically long and electrically short structural concept is proposed to enhance the characteristics of a PSC by employing selectively grown single crystalline TiO2 nanorods. The approach has the merit of increasing the electro n-hole separati on effectively and en ables a thicker active layer to be coated without electrical loss by using TiO2 nano rods as an electr on pathway. Moreover, selectively grow n TiO2 nano rods in crease the optical path of the in cide nt light via scatteri ng effects and en able a smooth coati ng of the active layer. Nano imprint lithography and hydrothermal growth were employed to fabricate selectively grow n TiO2 nanorod substrates. The fabricated solar cell exhibits an efficiency of 19.86% with a current density, open-circuit voltage, and fill factor of 23.13 mA/cm^2, 1.120 V, and 76.69%, respectively. Time-resolved photoluminescence, ultraviolet-visible (UV-Vis) spectroscopy, and the incident phot on to current efficiency (IPCE) an alysis were conducted to understand the factors resp on sible for the improvement in characteristics of the fabricated PSCs.
基金supported by the National Natural Science Foundation of China(51472203 and 51521061)the Natural Science Basic Research Plan in Shaanxi Province of China(2014JM6233)"111" project of china(B08040)
文摘MC3T3-E1 osteoblasts were cultured on H2O2- modified and unmodified carbon/carbon （H-C/C and C/C） composites for one week in order to evaluate differences in cell adhesion, spreading, and proliferation. The results indicated a certain degree of enhancement in the cell adhesion capability of osteoblasts cultured on H-C/C samples. Cellu- lar morphologies after cell adhesion were observed via scan- ning electron microscopy （SEM）, which showed that the cells adhered more closely and spread more widely on the H-C/C sample surface. However, no cell appeared in several mul- tiple and continuous types of minor pores on both the C/C and H-C/C surfaces. In addition, two unique situations were observed on the H-C/C samples： an outline change of the osteoblasts was observed when the cells spread across some minor pores, and the cells entered and adhered well in some larger pores.
