Size-controlled growth of ZnSe nanocrystals for high-performance photocatalytic HO production in pure water.

Semiconductor photocatalysis is deemed as a novel and promising process that can produce HO from earth-abundant water and gaseous dioxygen using sunlight as the energy supply. The searching of novel catalysts for photocatalytic HO production has received increasing attention in the last few years. Herein, size-controlled growth of ZnSe nanocrystals was realized a solvothermal method by varying the amount of Se and KBH.

Effects of Additives on Electrochromic Properties of Nanocrystalline Tungsten Oxide Films Prepared by Complexation-Assisted Sol-Gel Method.

To improve the electrochromic (EC) properties of sol-gel-derived WO films, a series of organic small molecules, such as dopamine (DA), catechol, tyramine, phenol and 2-phenylethylamine, were added into peroxotungstic acid precursor sols as structure-directing additives, and five modified WO films were prepared by a simple and low-cost complexation-assisted sol-gel method. The effects of the above additives on the EC properties of the modified WO films have been studied in detail. Compared with the pure WO polycrystalline film, all the modified films combine the advantages of nanocrystalline and amorphous phases and show higher EC properties attributed to the unique nanocrystal-embedded amorphous structure.

Oxygen-powered flower-like FeMo@CeO self-cascade nanozymes: a turn-on enhancement fluorescence sensor.

Enzyme cascade reactions in organisms have sparked tremendous interest for their coupled catalysis-facilitated efficient biochemical reactions. However, multi-enzyme cascade nanozymes remain largely unused. In the work, flower-like porous ceria-based integrated enzymes (INAzyme), FeMo@CeO (FMC-), were readily prepared using an efficient thermally induced process.

An Unprecedented FeMo @Ce-Uio-66 Nanocomposite with Cascade Enzyme-Mimic Activity as Colorimetric Sensing Platform.

Introducing the idea of integrated design and cascade activity into nanozyme, the novel integrated nanozymes (INAzymes), FeMo @Ce-Uio-66 (FC-66(n)), were designed and synthesized by encapsulating iron-based polyoxometalates (FeMo ) into the ceria-based metal-organic framework (Ce-Uio-66). Due to the oxygen-driven reversible Ce /Ce couple sites, the "Fenton-like" effect by iron centers, the "nanoscale proximity" effects by nanocages, and their synergistic effects, FC-66(n) as INAzymes exhibit elegant cascade enzyme-mimic activities (oxidase-, peroxidase-, and Fenton-like activity), which realizes INAzyme activities based on polyoxometalates based metal-organic framework (POMOFs). By employing dopamine (DA) detection as a model reaction, a high-efficient fluorescent "turning-on-enhanced" platform under near neutral conditions was established.

Seeded Growth of Au@CuO Core-Shell Mesoporous Nanospheres and Their Photocatalytic Properties.

We report a facile synthesis of Au@CuO core-shell mesoporous nanospheres with tunable size in the aqueous phase seeded growth. The success of the current work relies on the use of a halide-free copper (Cu) precursor and n-oleyl-1,3-propanediamine as a capping agent to facilitate the formation of a copperish oxide shell with a mesoporous structure and the presence of mixed oxidation states of Cu. By varying the amount of spherical Au seeds while keeping other parameters unchanged, their diameters could be readily tuned without noticeable change in morphology.

Hollow POM@MOF-derived Porous NiMo @Co O for Biothiol Colorimetric Detection.

Developing highly active and sensitive peroxidase mimics for -cysteine ( -Cys) colorimetric detection is very important for biotechnology and medical diagnosis. Herein, polyoxometalate-doped porous Co O composite (NiMo @Co O ) was designed and prepared for the first time. Compared with pure and commercial Co O , NiMo @Co O (n) composites exhibit the enhanced peroxidase-mimicking activities and stabilities due to the strong synergistic effect between porous Co O and multi-electron NiMo clusters.

Effects of Polyoxometalates on the Hydroxylation of N-Heterocyclic Ligands.

Four polyoxometalate (POM)-based Cu complexes with the hydroxylated pyridine analogue 3-(2-hydroxylpyrid-4-yl)-5-(1-1,2,4-triazol-3-yl)-1,2,4-triazolyl (btpo), H{[Cu(btpo)](PWO)}·2HO (), H{[Cu(btpo)](PMoO)}·2HO (), H{[Cu(btpo)](SiWO)·SO (), and H{[Cu(btpo)](SiWO)}·8HO (), were synthesized hydrothermally under acid conditions. Single-crystal X-ray structural analysis reveals that 3-(pyrid-4-yl)-5-(1-1,2,4-triazol-3-yl)-1,2,4-triazolyl was hydroxylated into btpo in compounds -, again providing structural evidence for the Gillard mechanism, in which HO as a weak nucleophile can attack the α-C atom of N-heterocyclic molecules at a lower pH value (ca. 1.

Polyelectrolyte-functionalized reduced graphene oxide wrapped helical POMOF nanocomposites for bioenzyme-free colorimetric biosensing.

For the sake of effective colorimetric sensing-pattern, a sensitive colorimetric sensor was conceived based on polyoxometalates based metal-organic frameworks (POMOFs) and polydiallyldimethylammonium chloride functionalized reduced graphene oxide (PDDA-rGO) for the first time, in which PDDA as a "glue" molecule turns rGO nanosheets into general platforms for bonding POMOFs nanoparticles. Herein, a new POMOF compound with fascinating helices-on-helices feature, [Ni(Trz)(HO)][SiWO]4HO (Trz = 1,2,4-triazole) (abbreviated as NiSiW), was synthesized and characterized, then PDDA-rGO sheet as dispersive and conductive material was successfully introduced to NiSiW fabricating new PDDA-rGO/NiSiW-n nanocomposites, (abbreviated as PMPG-n). The resulting PMPG-n nanocomposites as peroxidase mimetic show excellent catalytic activities under extreme condition (pH value 2.

Iron reduction and diopside-based glass ceramic preparation based on mineral carbonation of steel slag.

In this article, a new process for treating steel slag and CO simultaneously and preparing calcium carbonate, metallic iron, and glass ceramics without wastewater or gas production is proposed. The reduction of iron and preparation of diopside glass ceramics are studied in this paper, and the results show that the carbon thermal reduction product of the original slag does not reach its melting point, and the slag and iron are well separated in the samples containing the leached steel slag and added silica. Part of the parent glass is converted into a glass ceramic after heat treatment, and the crystalline phases of samples are melilite, diopside, and partial melilite, and diopside and anorthite, respectively.

Assembly of 12-Tungstovanadate-Templated Nanocage and Nanocomposites with Single-Walled Carbon Nanotubes as Anodes in Lithium-Ion Batteries.

A new 12-tungstovanadate-templated 3D nanocage framework, Ag(μ-ttz)(HO)(VWO) (VW@MOCF), was designed based on a "molecular library", hydrothermally synthesized, structurally characterized, and explored as anode material for lithium-ion batteries (LIBs). Combination of the structural superiority of VW@MOCF with the good electrical conductivity of the single-walled carbon nanotubes (SWNTs) renders the VW@MOCF/SWNT-2 nanocomposite reasonable electrochemical performance and stability as anode materials of LIBs. The successful cooperative fabrication of nanocages and polyoxometalate (POMs) must initiate extensive research interests.

Heightened Integration of POM-based Metal-Organic Frameworks with Functionalized Single-Walled Carbon Nanotubes for Superior Energy Storage.

To increase the conductivity of polyoxometalate-based metal-organic frameworks (POMOFs) and promote their applications in the field of energy storage, herein, a simple approach was employed to improve their overall electrochemical performances by introducing a functionalized single-walled carbon nanotubes (SWNT-COOH). A new POMOF compound, [Cu (trz) Cl (H O) ][PW O ] (CuPW), was successfully synthesized, then the size-matched functionalized SWNT-COOH was introduced to fabricate CuPW/SWNT-COOH composite (PMNT-COOH) by employing a simple sonication-driven periodic functionalization strategy. When the PMNT-COOH nanocomposite was used as the anode material for Lithium-ion batteries (LIBs), PMNT-COOH(3) (CuPWNC:SWNT-COOH=3:1) showed superior behavior of energy storage, a high reversible capacity of 885 mA h g up to a cycle life of 170 cycles.

The Indirect Mineral Carbonation of Electric Arc Furnace Slag Under Microwave Irradiation.

The indirect mineral carbonation of industrial residues is one of the potential technologies for CO sequestration. In this paper, the leaching and carbonation of electric arc furnace (EAF) slag under microwave irradiation was investigated. The experimental results show that the main reactive calcium-containing phase in the EAF slag carbonation process is calcium silicate, and the final leaching ratio of larger particles is lower than that of smaller particles due to the silica layer produced on the surface of the calcium silicate.

Enhancing the colorimetric detection of HO and ascorbic acid on polypyrrole coated fluconazole-functionalized POMOFs.

A new fluconazole-functionalized polyoxometalate-based metal-organic framework (POMOF) [Ag(FKZ)(HO)][HSiWO] (AgFKZSiW) was successfully constructed, and its polypyrrole (PPy) coated composite AgFKZSiW@PPy was also obtained via a facile 'in situ' oxidation polymerization process. The peroxidase-like activity evaluation indicates that the maximized synergistic effect from the integration of PPy, SiW clusters, HFKZ drug molecules, and Ag ions deeply enhanced the overall performance. More importantly, AgFKZSiW@PPy exhibits the fastest response time (30 s) among all the reported peroxidase mimics to date, including the pristine AgFKZSiW (2 min).