The presence of naphthenic acids in oil sand products and process streams is the cause of toxicity to aquatic life and corrosion. The removal of organic acids from tailings pond water reduces the negative impact on ma...The presence of naphthenic acids in oil sand products and process streams is the cause of toxicity to aquatic life and corrosion. The removal of organic acids from tailings pond water reduces the negative impact on marine life. The ultra-violet (UV) photocatalytic reduction of commercial naphthenic acid in water using TiO2-zeolitecomposites showed a significant decrease in the concentration of naphthenic acid, accompanied by an increase in carbon dioxide formation;the presence of carbon dioxide signifies degradation of the naphthenic acids. Mixtures of the acid and photocatalyst kept in the dark did not show any concentration changes. The extent of naphthenic acid reduction by UV light was verified by the reduction in total acidity. The total acidity values of mixtures of the acid and TiO2-zeoliteexposed to UV decreased by 31% compared to mixtures kept in the dark. A reduction in total acidity may lead to a decrease in the toxicity of naphthenic acid contaminated water.展开更多
This study used a Polyindole in combination with TiO2 nanocatalyst as an efficient heterogeneous catalyst to carry out a multi-component Hantzsch reaction involving different aromatic aldehydes with methyl acetoacetat...This study used a Polyindole in combination with TiO2 nanocatalyst as an efficient heterogeneous catalyst to carry out a multi-component Hantzsch reaction involving different aromatic aldehydes with methyl acetoacetate, and aqueous ammonium to create 1,4-dihydropyridine derivatives under solvent free condition at ambient temperature. A broad range of aldehydes and methyl acetoacetates, ranging from heteroaromatic to polyaromatic one, with high level of functional group tolerance can be used to provide the desired products possessing relevant medicinal moiety in high yields. This technology has prospective advantages over current protocols, including the utilization of a cheap, stable, recyclable, and safe catalyst, quicker reaction times with higher yields and simple product isolation.展开更多
The simulation by the Monte Carlo method executed by the software PyPENELOPE proved effective to specify the particle propagation characteristics by calculating the absorption fractions, backscattering and transmissio...The simulation by the Monte Carlo method executed by the software PyPENELOPE proved effective to specify the particle propagation characteristics by calculating the absorption fractions, backscattering and transmission of electrons and secondary photons under the incidence of 0.5 to 20 KeV range of primary electrons. More than 99.9% of the primary electrons were transmitted in the 125 nm thick MgO/TiO<sub>2</sub> material at 20 KeV. This occurred because several interactions took place in the transmitted primary irradiation such as characteristic, fluorescence, and bremsstrahlung produced when of the occupation of the KL3, KL2, KM3, and KM2 shell and sub-shell of titanium and magnesium which are the elements with a high atomic number in the material. The transmission particle characteristic of this material is therefore an indicator capable of improving the electrical performance and properties of the sensor.展开更多
This study focused on the development and characterization of TiO<sub>2</sub>-PES composite fibers with varying TiO<sub>2</sub> loading amounts using a phase inversion process. The resulting co...This study focused on the development and characterization of TiO<sub>2</sub>-PES composite fibers with varying TiO<sub>2</sub> loading amounts using a phase inversion process. The resulting composite fibers exhibited a sponge-like structure with embedded TiO<sub>2</sub> nanoparticles within a polymer matrix. Their photocatalytic performance for ammonia removal from aqueous solutions under UV-A light exposure was thoroughly investigated. The findings revealed that PeTi8 composite fibers displayed superior adsorption capacity compared to other samples. Moreover, the study explored the impact of pH, light intensity, and catalyst dosage on the photocatalytic degradation of ammonia. Adsorption equilibrium isotherms closely followed the Langmuir model, with the results indicating a correlation between qm values of 2.49 mg/g and the porous structure of the adsorbents. The research underscored the efficacy of TiO<sub>2</sub> composite fibers in the photocatalytic removal of aqueous under UV-A light. Notably, increasing the distance between the photocatalyst and the light source resulted in de-creased hydroxyl radical concentration, influencing photocatalytic efficiency. These findings contribute to our understanding of TiO<sub>2</sub> composite fibers as promising photocatalysts for ammonia removal in water treatment applications.展开更多
TiO_(2)is the dominant and most widely researched photocatalyst for environmental remediation,however,the drawbacks,such as only responding to UV light(<5%of sunlight),low charge separation efficiency,and difficult...TiO_(2)is the dominant and most widely researched photocatalyst for environmental remediation,however,the drawbacks,such as only responding to UV light(<5%of sunlight),low charge separation efficiency,and difficulties in recycling,have severely hindered its practical application.Herein,we synthesized magnetically separable Fe_(3)O_(4)@MoS_(2)@mesoporous TiO_(2)(FMmT)photocatalysts via a simple,green,and template-free solvothermal method combined with ultrasonic hydrolysis.It is found that FMmT possesses a high specific surface area(55.09 m2·g−1),enhanced visible-light responsiveness(~521 nm),and remarkable photogenerated charge separation efficiency.In addition,the photocatalytic degradation efficiencies of FMmT for methylene blue(MB),rhodamine B(RhB),and tetracycline(TC)are 99.4%,98.5%,and 89.3%within 300 min,respectively.The corresponding degradation rates are 4.5,4.3,and 3.1 times higher than those of pure TiO_(2)separately.Owing to the high saturation magnetization(43.1 A·m^(2)·kg^(−1)),FMmT can achieve effective recycling with an applied magnetic field.The improved photocatalytic activity is closely related to the effective transport of photogenerated electrons by the active interlayer MoS_(2) and the electron–hole separation caused by the MoS_(2)@TiO_(2)heterojunction.Meanwhile,the excellent light-harvesting ability and abundant reactive sites of the mesoporous TiO_(2)shell further boost the photocatalytic efficiency of FMmT.This work provides a new approach and some experimental basis for the design and performance improvement of magnetic photocatalysts by innovatively incorporating MoS2 as the active interlayer and integrating it with a mesoporous shell.展开更多
Lithium metal anode is almost the ultimate choice for high-energy density rechargeable batteries, but its uneven electrochemical dissolution-deposition characteristics lead to poor cycle stability and lithium dendrite...Lithium metal anode is almost the ultimate choice for high-energy density rechargeable batteries, but its uneven electrochemical dissolution-deposition characteristics lead to poor cycle stability and lithium dendrites safety problems. The fundamental solution to the problems is to interfere electrodeposition process of lithium metal so that it can be carried out reversibly and stably. In this work, an inverse-opal structured TiO2membrane with a thickness of only ~1 μm is designed to regulate the electrodeposition behavior of lithium metal, in which the ordered channels homogenize mass transfer process, the anatase TiO_(2)walls of the ion channels reduce desolvation barrier of solvated lithium-ions, and the spherical cavities with a diameter of ~300 nm confine migration of the adsorbed lithium atoms during electrocrystallization to diminish overpotential of lithium. These systematic effects cover and essentially change the whole process of electrodeposition of lithium metal and eliminate the possibility of lithium dendrite formation. The as-obtained lithium metal electrode delivers a Coulombic efficiency of 99.86% in the 100th cycle, and maintains a low deposition overpotential of 0.01 V for 800 h.展开更多
文摘The presence of naphthenic acids in oil sand products and process streams is the cause of toxicity to aquatic life and corrosion. The removal of organic acids from tailings pond water reduces the negative impact on marine life. The ultra-violet (UV) photocatalytic reduction of commercial naphthenic acid in water using TiO2-zeolitecomposites showed a significant decrease in the concentration of naphthenic acid, accompanied by an increase in carbon dioxide formation;the presence of carbon dioxide signifies degradation of the naphthenic acids. Mixtures of the acid and photocatalyst kept in the dark did not show any concentration changes. The extent of naphthenic acid reduction by UV light was verified by the reduction in total acidity. The total acidity values of mixtures of the acid and TiO2-zeoliteexposed to UV decreased by 31% compared to mixtures kept in the dark. A reduction in total acidity may lead to a decrease in the toxicity of naphthenic acid contaminated water.
文摘This study used a Polyindole in combination with TiO2 nanocatalyst as an efficient heterogeneous catalyst to carry out a multi-component Hantzsch reaction involving different aromatic aldehydes with methyl acetoacetate, and aqueous ammonium to create 1,4-dihydropyridine derivatives under solvent free condition at ambient temperature. A broad range of aldehydes and methyl acetoacetates, ranging from heteroaromatic to polyaromatic one, with high level of functional group tolerance can be used to provide the desired products possessing relevant medicinal moiety in high yields. This technology has prospective advantages over current protocols, including the utilization of a cheap, stable, recyclable, and safe catalyst, quicker reaction times with higher yields and simple product isolation.
文摘The simulation by the Monte Carlo method executed by the software PyPENELOPE proved effective to specify the particle propagation characteristics by calculating the absorption fractions, backscattering and transmission of electrons and secondary photons under the incidence of 0.5 to 20 KeV range of primary electrons. More than 99.9% of the primary electrons were transmitted in the 125 nm thick MgO/TiO<sub>2</sub> material at 20 KeV. This occurred because several interactions took place in the transmitted primary irradiation such as characteristic, fluorescence, and bremsstrahlung produced when of the occupation of the KL3, KL2, KM3, and KM2 shell and sub-shell of titanium and magnesium which are the elements with a high atomic number in the material. The transmission particle characteristic of this material is therefore an indicator capable of improving the electrical performance and properties of the sensor.
文摘This study focused on the development and characterization of TiO<sub>2</sub>-PES composite fibers with varying TiO<sub>2</sub> loading amounts using a phase inversion process. The resulting composite fibers exhibited a sponge-like structure with embedded TiO<sub>2</sub> nanoparticles within a polymer matrix. Their photocatalytic performance for ammonia removal from aqueous solutions under UV-A light exposure was thoroughly investigated. The findings revealed that PeTi8 composite fibers displayed superior adsorption capacity compared to other samples. Moreover, the study explored the impact of pH, light intensity, and catalyst dosage on the photocatalytic degradation of ammonia. Adsorption equilibrium isotherms closely followed the Langmuir model, with the results indicating a correlation between qm values of 2.49 mg/g and the porous structure of the adsorbents. The research underscored the efficacy of TiO<sub>2</sub> composite fibers in the photocatalytic removal of aqueous under UV-A light. Notably, increasing the distance between the photocatalyst and the light source resulted in de-creased hydroxyl radical concentration, influencing photocatalytic efficiency. These findings contribute to our understanding of TiO<sub>2</sub> composite fibers as promising photocatalysts for ammonia removal in water treatment applications.
基金financially supported by the National Key R & D Projects (Nos. 2021YFC1910504, 2019YFC1907101, 2019YFC1907103, and 2017YFB0702304)the Key R & D Project in Ningxia Hui Autonomous Region, China (No. 2020BCE01001)+6 种基金the Key and Normal Projects National Natural Science Foundation of China (Nos. U2002212 and 51672024)the Xijiang Innovation and Entrepreneurship Team (No. 2017A0109004)the Fundamental Research Funds for the Central Universities (Nos. FRF-BD-20-24A, FRF-TP-20-031A1, FRF-IC-19-017Z, FRF-GF-19-032B, and 06500141)the Integration of Green Key Process Systems MIIT, Natural Science Foundation of Beijing Municipality (No. 2214073)the Guangdong Basic and Applied Research Foundation, China (No. 2020A1515110408)the Foshan Science and Technology Innovation Special Foundation, China (No. BK21BE002)the Postdoctor Research Foundation of Shunde Graduate School of University of Science and Technology Beijing (No. 2020BH004)
文摘TiO_(2)is the dominant and most widely researched photocatalyst for environmental remediation,however,the drawbacks,such as only responding to UV light(<5%of sunlight),low charge separation efficiency,and difficulties in recycling,have severely hindered its practical application.Herein,we synthesized magnetically separable Fe_(3)O_(4)@MoS_(2)@mesoporous TiO_(2)(FMmT)photocatalysts via a simple,green,and template-free solvothermal method combined with ultrasonic hydrolysis.It is found that FMmT possesses a high specific surface area(55.09 m2·g−1),enhanced visible-light responsiveness(~521 nm),and remarkable photogenerated charge separation efficiency.In addition,the photocatalytic degradation efficiencies of FMmT for methylene blue(MB),rhodamine B(RhB),and tetracycline(TC)are 99.4%,98.5%,and 89.3%within 300 min,respectively.The corresponding degradation rates are 4.5,4.3,and 3.1 times higher than those of pure TiO_(2)separately.Owing to the high saturation magnetization(43.1 A·m^(2)·kg^(−1)),FMmT can achieve effective recycling with an applied magnetic field.The improved photocatalytic activity is closely related to the effective transport of photogenerated electrons by the active interlayer MoS_(2) and the electron–hole separation caused by the MoS_(2)@TiO_(2)heterojunction.Meanwhile,the excellent light-harvesting ability and abundant reactive sites of the mesoporous TiO_(2)shell further boost the photocatalytic efficiency of FMmT.This work provides a new approach and some experimental basis for the design and performance improvement of magnetic photocatalysts by innovatively incorporating MoS2 as the active interlayer and integrating it with a mesoporous shell.
基金Financial supports from the National Key Research and Development Program (2016YFB0100200)National Natural Science Foundation of China (21935006)。
文摘Lithium metal anode is almost the ultimate choice for high-energy density rechargeable batteries, but its uneven electrochemical dissolution-deposition characteristics lead to poor cycle stability and lithium dendrites safety problems. The fundamental solution to the problems is to interfere electrodeposition process of lithium metal so that it can be carried out reversibly and stably. In this work, an inverse-opal structured TiO2membrane with a thickness of only ~1 μm is designed to regulate the electrodeposition behavior of lithium metal, in which the ordered channels homogenize mass transfer process, the anatase TiO_(2)walls of the ion channels reduce desolvation barrier of solvated lithium-ions, and the spherical cavities with a diameter of ~300 nm confine migration of the adsorbed lithium atoms during electrocrystallization to diminish overpotential of lithium. These systematic effects cover and essentially change the whole process of electrodeposition of lithium metal and eliminate the possibility of lithium dendrite formation. The as-obtained lithium metal electrode delivers a Coulombic efficiency of 99.86% in the 100th cycle, and maintains a low deposition overpotential of 0.01 V for 800 h.
