Ag/TiO2 composites exhibited higher photocatalytic activity for degradation of methyl orange aqueous solution than that of nano-TiO2 alone.
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•Ag/TiO2 nanocomposites were prepared by a ...facile method.•The photocatalytic activity of Ag/TiO2 was higher than that of nano-TiO2 alone.•Plasmonic absorption of Ag benefit the additional absorption of Ag/TiO2 in visible region.
Using a hydrothermal strategy combined with photoreduction process, Ag/TiO2 nanocomposites in which ultra-small metallic Ag anchored on nano-TiO2 were synthesized. The SEM, TEM, EDS, XRD, as well as UV–Vis-NIR spectrum were used to characterize the Ag/TiO2 nanocomposites. It can be drawn the conclusion that the TiO2 exhibited irregular cube with a diameter of 20–30 nm, and metallic Ag anchored on the surface of nano-TiO2. The addition of metallic Ag successfully broaden the photoresponse range from UV region to visible light region. Photocatalytic activity of Ag/TiO2 was evaluated by degradation of methyl orange in aqueous solution. The results showed that the degradation rate of methyl orange by Ag/TiO2 reached 65.4% in 120 min, indicating a higher photocatalytic activity of Ag/TiO2 than that of pure TiO2 nanomaterials. The additional absorption of Ag/TiO2 in visible region was attributed to the plasmonic absorption of Ag. Moreover, the kinetic behavior could be described in terms of Langmuir-Hinshelwood pseudo-first-order kinetic equation.
In this study, a multi-objective aerodynamic optimization is performed on the rotor airfoil via an improved MOPSO (multi-objective particle swarm optimization) method. A database of rotor airfoils ...containing both geometric and aerodynamic parameters is established, where the geometric parameters are obtained via the CST (class shape transformation) method and the aerodynamic parameters are obtained via CFD (computational fluid dynamics) simulations. On the basis of the database, a DBN (deep belief network) surrogate model is proposed and trained to accurately predict the aerodynamic parameters of the rotor airfoils. In order to improve the convergence rate and global searching ability of the standard MOPSO algorithm, an improved MOPSO framework is established. By embedding the DBN surrogate model into the improved MOPSO framework, multi-objective and multi-constraint aerodynamic optimization for the rotor airfoil is performed. Finally, the aerodynamic performance of the optimized rotor airfoil is validated through CFD simulations. The results indicate that the aerodynamic performance of the optimized rotor airfoil is improved dramatically compared with the baseline rotor airfoil.
In this study, MoS
2
/g-C
3
N
4
nanocomposites was prepared via an ultrasonication and calcination method and used for uranium ions removal from uranium containing solution. The optimum MoS
2
/g-C
3
...N
4
composites photocatalyst with the molar content of 3% MoS
2
had the highest photocatalytic performance (93% reduction efficiency within 60 min irradiation time), which was approximately five times faster than that of pure g-C
3
N
4
. MoS
2
plays pivotal roles in light adsorption, transfer and charge separation in photoreduction of U(VI) process.
Highlights
A nanofiber composite reinforced organohydrogel with multifunctionality is prepared.
The composite organohydrogel possesses multiple interfacial bondings and multi-level strengthening and ...toughening mechanism is proposed.
The composite organohydrogel exhibits long-term strain sensing stability and can be used for high performance electromagnetic interference shielding.
Composite organohydrogels have been widely used in wearable electronics. However, it remains a great challenge to develop mechanically robust and multifunctional composite organohydrogels with good dispersion of nanofillers and strong interfacial interactions. Here, multifunctional nanofiber composite reinforced organohydrogels (NCROs) are prepared. The NCRO with a sandwich-like structure possesses excellent multi-level interfacial bonding. Simultaneously, the synergistic strengthening and toughening mechanism at three different length scales endow the NCRO with outstanding mechanical properties with a tensile strength (up to 7.38 ± 0.24 MPa), fracture strain (up to 941 ± 17%), toughness (up to 31.59 ± 1.53 MJ m
−3
) and fracture energy (up to 5.41 ± 0.63 kJ m
−2
). Moreover, the NCRO can be used for high performance electromagnetic interference shielding and strain sensing due to its high conductivity and excellent environmental tolerance such as anti-freezing performance. Remarkably, owing to the organohydrogel stabilized conductive network, the NCRO exhibits superior long-term sensing stability and durability compared to the nanofiber composite itself. This work provides new ideas for the design of high-strength, tough, stretchable, anti-freezing and conductive organohydrogels with potential applications in multifunctional and wearable electronics.
It is a central issue to eliminate radioactive uranium (U(VI)) efficiently from water. In this manuscript, β-cyclodextrin was cross-linked with 2,3,5,6-tetrafluoro-1,4-benzenedicarbonitrile, and then ...a carboxylation reaction was used to prepare porous cross-linked polymers rich in carboxyl groups (CA-PCDPs). Subsequently, magnetic nanoparticles (MNPs) were loaded onto the CA-PCDPs via coprecipitation, and magnetic porous β-cyclodextrin polymer nanoparticles (CA-PCDP@MNPs) were successfully obtained, which were used for efficient elimination of U(VI) from nuclear wastewater solution. Moreover, SEM, FTIR, VSM, BET, and XRD were employed to investigate the CA-PCDP@MNP and found that it had a well-developed porous structure, high specific surface area, and abundant oxygen-containing functional groups (carboxyl, hydroxyl, C-O-C, Fe-O, etc.), providing sufficient active sites for chelating uranyl ions. Experiments illustrated that the CA-PCDP@MNP had efficient removal ability for U(VI), and the maximum theoretical adsorption amount for U(VI) reached 245.66 mg/g at pH 6.0 and 303 K. Moreover, the adsorption process was more suitable for the quasi second-order kinetic model and Langmuir adsorption isotherm model, indicating that the adsorption process was chemical adsorption. Meanwhile, the CA-PCDP@MNPs also exhibited fast response magnetic recovery ability and excellent regeneration and recycling ability. In addition, the data of the adsorption mechanism demonstrated that oxygen-containing functional groups, which were rich on the surface of CA-PCDP@MNPs, were the main binding active sites of U(VI). From the above results, it can be deduced that the CA-PCDP@MNP has a good application prospect in the practical application of nuclear wastewater treatment.
Hydrated V2O5 with unique physical and chemical characteristics has been widely used in various function devices, including solar cells, catalysts, electrochromic windows, supercapacitors, and ...batteries. Recently, it has attracted extensive attention because of the enormous potential for the high-performance aqueous zinc ion battery cathode. Although great progress has been made in developing applications of hydrated V2O5, little research focuses on improving current synthesis methods, which have disadvantages of massive energy consumption, tedious reaction time, and/or low efficiency. Herein, an improved synthesis method is developed for hydrated V2O5 nanoflakes according to the phenomenon that the reactions between V2O5 and peroxide can be dramatically accelerated with low-temperature heating. Porous hydrated V2O5 nanoflake gel was obtained from cheap raw materials at 40 °C in 30 min. It shows a high specific capacity, of 346.6 mAh/g, at 0.1 A/g; retains 55.2% of that at 20 A/g; and retains a specific capacity of 221.0 mAh/g after 1800 charging/discharging cycles at 1 A/g as an aqueous zinc ion battery cathode material. This work provides a highly facile and rapid synthesis method for hydrated V2O5, which may favor its applications in energy storage and other functional devices.
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•Magnetic orderly mesoporous α-Fe2O3 nanocluster has been synthesized by a simple calcination method..•Calcination time can regulate the forming pore sizes and specific surface area ...of α-Fe2O3 nanocluster..•Magnetic orderly mesoporous α-Fe2O3 nanocluster exhibits rapid and efficient adsorption for arsenic(III,V).
A calcination time regulation method has been unprecedentedly used to adjust the orderly meso-structure of novel α-Fe2O3 nanoclusters derived from MIL-100(Fe) (MIL: Materials of Institute Lavoisier). The as-synthesized magnetic orderly mesoporous α-Fe2O3 nanoclusters were characterized by XRD, SEM, TEM, TGA, N2 adsorption-desorption isotherms, VSM, Zeta potential, FTIR and XPS. The 6h calcinated α-Fe2O3 nanocluster exhibited the optimal properties, including the high specific surface area and the orderly mesoporous properties, which facilitate the arsenic(III,V) adsorption capacity. The maximum adsorption capacities of As(III) and As(V) were 109.89 and 181.82mgg−1, respectively, and adsorption equilibrium can be reached just within 30min. The kinetics intra-particle diffusion model and adsorption isotherms reveal that the adsorption rate is controlled by pore diffusion and the adsorption process belongs to Langmuir monolayer adsorption. These results indicate that the orderly mesoporous structure of α-Fe2O3 nanoclusters plays a key role in rapid and efficient adsorption for arsenic(III,V). Meanwhile, adsorption mechanism verifies that arsenic can react with active sites (Fe-OH) to form complexes by Fe-O-As bond. Moreover, α-Fe2O3 nanocluster can be separated easily due to its excellent magnetism. Above all, the magnetism orderly mesoporous α-Fe2O3 nanocluster is a promising adsorbent for emergent treatment of arsenic in practice.
Exploiting dual-functional photocatalysts to reduce U(VI) and oxidize Sb(III) is a challenging but efficient way of achieving simultaneous purification. Herein, Fe3O4/TiO2/g-C3N4 (FTC) ...double-heterostructures with customized stacking order were designed as a dual-functional photocatalyst to collaborative remove U(VI) and Sb(III). When introducing TiO2/g-C3N4 heterojunction and bridging it with Fe3O4/TiO2 using TiO2 as the intermediate layer, FTC showed outstanding photocatalytic activity and can simultaneously achieve 96.5% U(VI) reduction and 88.5% Sb(III) oxidation under sunlight, achieving 90.9% and 85.8% in natural wastewater. The constructed FTC architecture of an S-scheme framework can achieve efficient co-removals of U(VI) and Sb(III) by enhancing the separation and transferal of photoexcited charge carriers with outstanding redox ability employing different reaction sites. TiO2 and g-C3N4 accumulated electrons and holes, respectively, and completed concurrent redox reactions, following the path determined by N(g−C3N4) and O(TiO2), which enhanced the separation of photoexcited carriers. The two-way effect of O2• ⁻ activated by FTC supported positive feedback coupling relationships between the reduction of U(VI) and Sb(III) oxidation. This study not only fulfills the co-removal of U(VI) and Sb (III) for the first time with a capacity of 170.6 and 15.9 mg/g in engineering applications, but also proposes the reaction mechanism of a two-step continuous concerted redox reaction causing high removal determined by the electronic structure, so it lays a foundation for further development of highly efficient and stable heterojunction photocatalysts with concerted effects applied in complex wastewater treatment.
Hydrogels are widely used in tissue engineering, soft robots, wearable electronics, etc. However, it remains a great challenge to develop hydrogels possessing simultaneously high strength, large ...stretchability, great fracture energy, and good fatigue threshold to suit different applications. Herein, a novel solvent‐exchange‐assisted wet‐annealing strategy is proposed to prepare high performance poly(vinyl alcohol) hydrogels by extensively tuning the macromolecular chain movement and optimizing the polymer network. The reinforcing and toughening mechanisms are found to be “macromolecule crystallization and entanglement”. These hydrogels have large tensile strengths up to 11.19 ± 0.27 MPa and extremely high fracture strains of 1879 ± 10%. In addition, the fracture energy and fatigue threshold can reach as high as 25.39 ± 6.64 kJ m−2 and ≈1233 J m−2, respectively. These superb mechanical properties compare favorably to those of other tough hydrogels, organogels, and even natural tendons and synthetic rubbers. This work provides a new and effective method to fabricate superstrong, tough, stretchable, and anti‐fatigue hydrogels with potential applications in artificial tendons and ligaments.
A novel solvent‐exchange‐assisted wet‐annealing strategy is first proposed to develop superstrong and tough hydrogels with extremely high stretchability and excellent fatigue resistance. The hydrogels have extremely high tensile strength of 11.19 ± 0.27 MPa, a fracture toughness of 82.28 ± 2.89 MJ m−3 with stretchability up to 1879 ± 10%, and a fatigue threshold of ≈1233 J m−2.
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•This plate photocatalyst is easy to recycle and does not pollute the salt lake.•This photocatalyst can efficiently extract and recover U from real salt lakes.•This photocatalyst ...amplifies the benefits of anoxic conditions in salt lake.•Coordination, environmental regulation, and steric effects lead to high selectivity.
Photocatalysis has attracted intensive interest in uranium (U) extraction and recovery from salt lakes which play a critical role in guaranteeing a sustainable nuclear energy supply. However, some severe working conditions such as the intricate environment, low concentration, and powder materials limit the process's effectiveness and application popularize value in salt lakes. To address this, we meticulously designed an amidoxime-functionalized titanium dioxide nanoarrays plate photocatalyst (TNTPAO). TNTPAO can accumulate 94.5 % of U through extraction and recover 93.6 % over 3 cycles of adsorption/desorption in salt lakes. Bench-scale experiments also achieved a cumulative recovery rate of 85.5 % and a capacity exceeding 30 μg/cm2 following 96 h of treatment with a 15 L solution of salt lake, thus proving its reliability and practicality. The study discovered that hydrogen bonds, N atoms with uranium affinity, and steric effects ensure high selectivity. The variances in binding sites between TNTPAO with U(VI) and U(IV) guaranteed high efficiency and sustainability. Additionally, the oxygen-depleted environment regulated O2 to generate O2• –, which enhances the reduction of U(VI). The theoretical calculation introduced a novel adsorption and reduction mechanism of amidoxime-functionalized materials, offering guidance for resource recovery materials.
