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With the increasing demand for nuclear energy, uranium extraction from seawater and nuclear waste is becoming increasingly important due to the limitations of conventional uranium. Herein, sol-gel and hydrothermal methods prepared almond Na2TiOSiO4 with controllable crystallization. The growth mechanism was that almond Na2TiOSiO4 crystallizes along the {00 l} face parallel to the interlayer sodium ions plane and bottom surface of the TiO5 tetragonal pyramids, growing in all directions while stacking layer by layer, forming almond-shaped crystals composed of densely packed single crystals. Three different morphologic products (Almond, Almond-b, and Walnut) were obtained as uranium adsorbents by changing the acid-base ratio. Due to the higher specific surface area and surface potential, the adsorption capacity of Walnut was 2 times that of Almond, and the equilibrium time was half that of Almond-b. The adsorption mechanism of the adsorbent was proposed and confirmed. At low concentrations, electrostatic adsorption was dominant, and sodium ion exchange was present; at high concentrations, in addition to electrostatic adsorption and sodium ion exchange mechanisms, uranium crystallization was also observed. In addition, adsorbents have great promise for practical applications such as the recovery of uranium from seawater and nuclear wastewater, as well as recycling.

Uranyl ion pollution is a serious environmental problem, and developing novel adsorption materials is essential for uranyl ion removal. V-doped Na2TiOSiO4 multiwalled nanotubes (Vx-Na2TiOSiO4 MWNTs) were prepared by an effective hydrothermal process and their uranyl ion adsorption properties were investigated. The special morphology, high specific surface area, and surface potential made MWNTs an excellent adsorbent. Appropriate doping can further improve the adsorption performance of nanotubes. The saturated adsorption capacities of nanotubes in aqueous solution and simulated seawater were 593.2 and 236.9 mg/g, respectively, and can reach 684.6 and 287.0 mg/g after appropriate doping. Proposed and proved the adsorption mechanism of nanotubes was the surface electrostatic adsorption mechanism, the Na+ replacement, and uranyl ion crystallization. In addition, nanotubes have excellent selectivity and recyclability. The finding in this work provides a fundamental understanding of the efficient usage of Vx-Na2TiOSiO4 MWNTs in practical applications.

V-doped Na2TiOSiO4 multiwalled nanotubes (Vx-Na2TiOSiO4 MWNTs) were prepared by an effective hydrothermal process and were characterized by SEM, XRD, FT-IR, Raman, TEM, 51V-ssNMR, 29Si-ssNMR and XPS methods. The results showed that the change of V5+ to V4+ was attributed to the reduction of the electronegative oxygen derived from the dehydration of the absorbed hydroxyl, and in this process, new oxygen vacancies resulting from electronegative oxygen were generated. Different from traditional structures, doped vanadium (V4+) replaced partly the position of titanium (Ti4+), which made Si4+ exist in two chemical coordination environments, Ti-O-Si and V-O-Si. The formation of Vx-Na2TiOSiO4 MWNTs was attributed to a curling process, and the unique morphology makes them have large pore volume and surface area to adsorb hydrogen. It adsorbed 0.388 wt% hydrogen even at the temperature of 77 K and hydrogen pressure of 1 bar, such a result provides a promising strategy for designing practical hydrogen storage materials. (c) 2021 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

VOX/TiO2–Ce0.9Zr0.1O2 catalyst exhibits high activity and selectivity in a wide temperature window.

Al-0.05Ga-0.05Sn-0.05Pb-xMg alloys with different Mg content have been prepared. Electrochemical tests including constant current discharge test, current polarization test, electrochemical impedance spectroscopy (EIS) test, and Tafel test are performed. The surface states of the alloys after constant current discharge were analyzed by scanning electron microscopy (SEM) and energy disperse spectroscopy (EDS). X-ray diffraction (XRD) analysis was carried out. We find that different Mg contents have great influence on discharge performance of aluminum alloy anodes by changing the corrosion behavior. The SEM and XRD show that Mg can influence the distribution of corrosion and change the grain size to improve the discharge performance of aluminum anodes. Al-0.05Ga-0.05Sn-0.05Pb-0.1Mg shows the best electrochemical performance due to uniform corrosion and proper grain size. At 800 mA cm−2 constant current discharge, the potential of the aluminum anode can reach − 1.54 V (vs Hg/HgO), and the utilization ratio is over 98%.

The adhesion of mussel foot proteins (Mfps) to a variety of surfaces has been widely investigated, but the mechanisms behind the mussel adhesion to surfaces with different properties are far from being understood.

A pH and salt dually responsive emulsion has been designed on the basis of a novel amphiphilic macromolecule. It was found that the water separation of an oil-in-water emulsion reached up to ∼60% after standing for 10 min at low pH. 2-(Diethylamino)ethyl methacrylate (DEA) residues were found to induce the macromolecules to protonate and to be hydrophilic at pH values between 2 and 6, resulting in dewetting from oil droplet surfaces in water. Besides, the macromolecules form aggregates with different structures at the water/oil interface, depending on the pH value or salt concentration of the emulsion system, enabling the system to be demulsified in response to the pH or salt stimulus. The experimental results also showed that with the addition of aluminium chloride at 100 mg L-1, the water separation was about 70% after 20 min. A possible mechanism with respect to demulsifying was proposed on the basis of an "ion bridge" among sodium acrylate (SA) residues, inducing the macromolecules to "cross-link" and become insoluble, and leading to oil/water separation. Furthermore, at a fixed pH of 5, addition of salt to the aqueous dispersion increased the degree of oil-water interfacial activity and batch emulsions were significantly unstable to coalesce at a low salinity of 25-50 mg L-1. This finding presents a new manipulation on emulsion stability and potential applications in the fields of oil recovery, wastewater treatment, sludge removal, and so on.

Nanostructured surfaces similar to those found in nasturtium leaf waxes were prepared by organic vapor deposition on a silicon wafer, with a range of crystal densities. The nanostructured surface consisting of 200 nm thick nonacosane showed the lowest adhesion. Bionic shark skin-like surfaces with different heights were prepared by reactive ion etching. Surfaces with a hierarchical structure were prepared by organic vapor deposition on the bionic shark skin with a thickness of 200 nm. 3,4-dihydroxyphenylalanine (DOPA) showed lower adhesion on the hierarchical structures as compared to the nanostructured surfaces, indicating that the surfaces with a hierarchical structure were strongly anti-adhesive and hydrophobic, with excellent resistance to water adhesion.

The preparation of FeOx-VOx-WOx-MnOx-CeOx/TiO2 catalyst by the ultrasound-substep-wet impregnation method for removing NOx from diesel engine exhausts has been demonstrated along with the excellent low-temperature selective catalytic reduction activity over a broad temperature window of 150-300 degrees C. The specific surface area, catalyst structure, composition and SCR reactivity tests of NO with NH3 at low temperatures have been investigated by nitrogen adsorption, X-ray diffraction, X-ray photoelectron spectroscopy, H-2 temperature programmed reduction, NH3 temperature programmed desorption and in situ DRIFTS measurements. The results show that the excellent activity is due to the well dispersed active components, the moderate ratio of V4+/W5+ and (Mn2++Mn3+)/Mn4+, the excellent redox property and the abundant acid sites. Iron plays the important role of inhibiting the agglomeration of metal oxide during the catalyst sintering and converting V and Mn to their higher oxidation states.

A new solid base, mesoporous K 2 O-MgO/ZrO 2 -La 2 O 3 , was prepared by hydrothermal and immersion process using a cationic surfactant C 16 H 33 (CH 3 ) 3 NBr (CTAB) as template．The samples were characterized by N 2 adsorption-desorption, X-ray diffraction(XRD), Raman spectroscope and CO 2 temperature programmed desorption(CO 2 -TPD). XRD and Raman spectra indicated that the catalyst calcined at 600°C and 700 °C remained surface and bulk tetragonal phase and good mesoporous characteristics when the content of K 2 O is less than 0.5. While the monoclinic phase is appeared on catalyst surface when the content of K 2 O is more than 0.5 calcined at 700 °C. CO 2 -TPD proves that there are two adsorption states at high temperature corresponding to super alkaline sites of K 2 O and undecomposed KNO 3 . The catalyst with 0.4 mol ratio of K 2 O to ZrO 2 calcined at 700 °C showed higher activity in the synthesis of di-2-ethylhexyl carbonate (DEHC) from dimethyl carbonate (DMC) and 2-ethylhexanol (EHOH).

MgO/ZrO2-La2O3-y solid base catalyst was prepared by precipitation immersion process. Raman spectroscope and X-ray powder diffraction (XRD) were used to determinate the surface phase and bulk phase of solid base catalyst. Temperature programmed desorption of CO2 (CO2-TPD) was employed to study the surface basicity of the catalyst. The results reveal that Mg2+ ion plays a key role in the stabilization of tetragonal phase ZrO2 not only in the bulk but also on the surface of catalyst when the Mg/Zr molar ratio is 0.4. The doping of La2O3 has the role of improving the dispersion of the active component MgO on ZrO2 surface, consequently resulting in the improvement of the catalytic activity of the catalyst rather than stabilizing tetragonal phase ZrO2.

K 2 O/ZrO 2 K 2 O/ZrO 2- La 2 O 3-x (x=0.4%, 0.5%, 0.6%, 0.7% and 0.8%) catalysts for the synthesis of di-2 ethylhexyl carbonate from dimethyl carbonate and 2-ethyl hexanol were prepared by impregnation method calcinated at 773K, 873K and 973K. The activity of K 2 O/ZrO 2- La 2 O 3- 0.6% catalyst reached the yield of 81.18% for di-2-ethylhexyl carbonate when the calcination temperature was 973K. XRD and Raman measurements of catalysts revealed that the tetragonal and monoclinic zirconia phase were observed in the catalysts. It was benefited to increase the basicity of catalysts that K 2 O dispersed on the surface of the carrier. The monoclinic zirconia phase decreased when the content of La increased.