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Ag/PW10V2/am-TiO2−x was designed by decorating OVs-enriched am-TiO2−x with Ag NPs and PW10V2. The formed Z-scheme heterojunction, Ag–am-TiO2−x interface and plentiful surface OVs account for its high photocatalytic efficiency in nitrogen fixation.

Sustainable solar-to-ammonia conversion under ambient conditions using air and water as feedstocks is a promising approach to supply low-concentrated ammonia (fertilizer) for farms. In the present work, the semiconductor-like polyoxometalate, tricobalt substituted silicotungstate [α-SiW9O37Co3(H2O)3]10− (SiW9Co3), is stabilized on a Bi2WO6 (BWO) substrate via a poly-dopamine (PDA) adhesive to construct a ternary SiW9Co3/PDA/BWO composite. In the Z-scheme SiW9Co3/PDA/BWO composite, the migration of photo-generated charger carriers between SiW9Co3 and BWO, with a narrow band gap, is facilitated by π–π* electronic delocalization of PDA. The catalytic efficiency of ternary SiW9Co3/PDA/BWO is 6.0 times higher than that of pristine BWO, owing to multiple chemisorptions of molecular nitrogen, the presence of oxygen vacancies, and efficient separation and migration of photo-generated electron–hole pairs. A quantitative reactivity–structure relationship is established according to the correlation between transient photocurrent response and catalytic efficiency. The enhancement factor of the Z-scheme mechanism is estimated to be 1.7–2.5. Essentially, the photo-driven nitrogen reduction reaction is carried out in pure water under both pure nitrogen and air atmospheres with visible light (and simulated sunlight) irradiation. Direct utilization of air and water as feedstocks highlights its promising prospects in marching towards a “solar ammonia refinery”, where the photo-driven nitrogen reduction devices are built near a farm to produce fertilizer as needed.

In this study, magnetically-recoverable core–shell catalysts with different amount of H3PW12O40 loading [Fe3O4@C@mTa2O5-NH2-PW12 (w%)] were prepared by the application of phosphotungstic acid supported on amino group functionalized magnetic core–shell mesoporous tantalum pentoxide microspheres. The prepared samples were characterized by FT-IR, N2-adsorption–desorption isotherms, TEM, SEM, Pyridine-IR analysis, XRD and magnetism. Fe3O4@C@mTa2O5-NH2-PW12 samples present both Bronsted and Lewis acidity, large BET surface area and high magnetization. The catalytic activity was evaluated by the acetalization of different aldehydes with diols, and the results show that Fe3O4@C@mTa2O5-NH2-PW12 (14.47%) catalyst exhibits the highest catalytic activity for acetalization of aldehydes with glycols with 94.5% conversion of benzaldehyde and 99% selectivity to benzaldehyde glycol acetal at 80 °C. The catalytic activity of the catalyst for acetalization is related to its total acidity and Bronsted–Lewis acid synergy. The catalyst Fe3O4@C@mTa2O5-NH2-PW12 can be easily recovered and reused for at least 5 times without obvious decrease of catalytic activity.

Herein, the mesoporous composite materials, mTiO2–ZrO2/PTAy-x (PTA = phosphotungstic acid, x represents the molar ratio of Ti to Zr, y represents the weight percent of PTA in mTiO2–ZrO2/PTA samples), have been prepared by the surfactant-assisted sol–gel method combined with a subsequent hydrothermal treatment. The as-prepared catalysts were fully characterized by FT-IR, XRD, SEM, TEM, XPS, DRS, PLs and nitrogen adsorption–desorption techniques. The results indicated that mTiO2–ZrO2 sample with the TiO2 and ZrO2 molar ratio of 3 exhibits good crystallinity, large internal surface areas and narrow-sized pores. The PTA clusters incorporated in mTiO2–ZrO2 frameworks preserve intact Keggin structure according to EDX, FT-IR and diffuse reflectance UV/vis/NIR spectroscopy. The band gap energy of as-prepared composites is reduced compared with single components. The PL experiments revealed that the obtained mTiO2–ZrO2 can strongly retard the recombination of photogenerated electrons and holes compared with a single oxide, and the introduction of PTA species can further improve the light adsorption and the photochemical stability, therefore efficiently promoting photocatalytic activity of the ternary composite materials. Photocatalytic experiments confirmed that mTiO2–ZrO2/PTA10-3 displayed highly efficient and durable activity for the photodegradation of methyl orange under simulated sunlight and photoreduction of Cr(VI) under visible light. The study of the photocatalytic mechanism revealed that superoxide radicals (∙O2−) and holes (h+) are the main active species. These materials are very stable in the photocatalytic reactions, and therefore, they are promising and efficient catalysts for practical applications.

Two new 2D frameworks of inorganic-organic hybrids, CuI4(bimb)4GeW12O40·2H2O (1) and CuII3Cl2(bimb)3(H2O)4GeW12O40·5H2O (2) were successfully synthesized under hydrothermal conditions by adjusting the stoichiometry of starting materials and pH values with the same starting materials. They were characterized by single crystal X-ray diffraction analysis, IR spectrum and magnetic measurements. Both of them are constructed by coordination polymer chains {CuI(CuII)-bimb}n and {GeW12O40} anions as building blocks. Compound 1 crystallizes in P-1 space group and exhibits a two-dimensional (2D) (3,4)-binodal layer, composed of wavelike {CuI-bimb}n polymer chains bridged by tetradentate [GeW12O40]4− polyanions, with a Schlafli symbol of (83)·(62·84). Compound 2 crystallizes in noncentrosymmetric space group P1 and exhibits a 2D (4,4) layer composed of one-dimensional (1D) tri-chains {CuII3(bimb)3Cl2(H2O)4}∞ constructed by unique three-nuclearity cluster {CuII3Cl2(H2O)4}4+ and bib molecules, bridged by bidentate [GeW12O40]4− anions. Magnetic measurements reveal that ferromagnetic interactions exist among the three-nuclearity cluster {Cu3Cl2O2(H2O)4} in 2.

A large X-shaped polyoxometalate, [As6Fe7Mo22O98]25− (1), has been synthesized and structurally characterized. The skeleton of 1 is composed of two monocapped hexavacant Keggin [AsMo7O27]9− units and two divacant Anderson [FeMo4O19]11− units fused together through a central Fe5O4 core and two μ4-As2O bridging units, resulting in a unique tetramer with C2h symmetry. The polyanion represents the largest iron-containing arsenomolybdate to date and it contains an unprecedented heptanuclear iron(III) cluster. The investigation of the magnetic properties shows that the Fe7 cluster exhibits an overall ferromagnetic interaction with a spin ground state of S = 7.5.

In this work, Bi2WO6 hollow microspheres containing oxygen vacancies (OVs-BWO) was synthesized by a solvothermal template-free method. Raman, EPR and XPS spectra provide sufficient evidence for the existence of OVs in the material. Its activity toward photocatalytic nitrogen fixation was evaluated. Experimental results showed that the OVs-BWO with a BET surface area of 80.5 m2·g−1 exhibited the ammonia yield of 106.4 μmol·gcat−1 under simulated sunlight for 2 h, which is ca. 18 times higher than that of equal-area nest-like Bi2WO6 without oxygen vacancies. The enhanced activity is mainly attributed to the metastable electrons within the sub-band (i.e., defect energy level) induced by oxygen vacancies to π anti-bonding orbitals of N2 with a manner of the non-radiative transfer, leading to the activation of nitrogen molecules. The activation and hydrogeneration processes of nitrogen at active site of OVs-BWO were studied by DFT calculation and the possible mechanisms were proposed. The sub-band extends the light absorption region of OVs-BWO to 700 nm. Transient photocurrent response showed that the sub-band electron excitation accelerates the transfer of charges and hinders the electron-hole recombination. It can be perfectly reused five times when air and nitrogen are used as nitrogen sources, thus the OVs-BWO hollow microspheres offer a promising alternative for efficient N2 fixation under ambient conditions.

Native human tissues possess incomparable biological performance due to their strong and viscoelastic mechanical properties, and biocompatible compositions. Herein, by a thermal polymerization and solvent hybridization method, we develop biomimetic polycitrate-gelatin hybrid polymers (PC-GT) with strong mechanical properties and tailored elastomeric behavior for tissue regeneration applications. The incorporation of gelatin significantly enhanced the mechanical properties and cellular biocompatibility of PC. PC-GT hybrids demonstrated the 135 times (from 7.5 to 1015MPa) and 11 times (from 4 to 46MPa) improvement for the elastomeric modulus and tensile strength respectively as compared with PC elastomers, while showing controlled stretchable and elastomeric behavior. In addition, PC-GT hybrids significantly improved the fibroblasts (L929) attachment and proliferation, suggesting their high biocompatibility. This study may provide a novel strategy to design biocompatible hybrid polymers with strong and elastomeric behavior for tissue regeneration and stretchable electronic devices applications.

Polyoxometalates based ionic liquids (POM-ILs) exhibit a high catalytic activity in oxidative desulfurization. In this paper, four new POM-IL hybrids based on transition metal mono-substituted Keggin-type phosphomolybdates, [Bmim]5[PMo11M(H2O)O39] (Bmim = 1-butyl 3-methyl imidazolium, M = Co2+, Ni2+, Zn2+, and Mn2+), have been synthesized and used as catalysts for the oxidation/extractive desulfurization of model oil, in which ILs are used as the extraction solvent and H2O2 as an oxidant under very mild conditions. The factors that affected the desulfurization efficiency were studied and the optimal reaction conditions were obtained. The results showed that the [Bmim]5[PMo11Co(H2O)O39] catalyst demonstrated the best catalytic activity, with sulfur-removal of 99.8%, 85%, and 63% for dibenzothiophene (DBT), 4,6-dimethyldibenzothiophene (4,6-DMDBT), and benzothiophene (BT), respectively, in the case of extraction combining with a oxidative desulfurization system under optimal reaction conditions (5 mL model oil (S content 500 ppm), n(catalyst) = 4 &mu, mol, n(H2O2)/n(Substrate) = 5, T = 50 &deg, C for 60 min with [Omim]BF4 (1 mL) as the extractant). The catalyst can be recycled at least 8 times, and still has stability and high catalytic activity for consecutive desulfurization. Probable reaction mechanisms have been proposed for catalytic oxidative/extractive desulfurization.

In this paper, hydrogen production by catalytic treatment of analgin pharmaceutical wastewater was systematically investigated in supercritical water (SCW) with a continuous reactor for the first time. The effect of sodium salts on the decomposition of analgin pharmaceutical wastewater in supercritical water was investigated in a continuous reactor. The results showed that NaHCO