One-pot hydrothermal synthesis of FeNbO4 microspheres for effective sonocatalysis.

FeNbO4 sonocatalysts were successfully synthesized by a simple hydrothermal route at pH values of 3, 5, 7, 9 and 11. The catalysts were characterized by XRD, XPS, TEM, SEM, N2 adsorption and DRS to analyse the effect of pH parameters on the physicochemical properties of the materials during hydrothermal synthesis. The sonocatalytic activity of FeNbO4 microspheres was evaluated by using acid orange 7 (AO7) as the simulated contaminant. The experimental results showed that the best sonocatalytic degradation ratio (97.45%) of organic dyes could be obtained under the conditions of an initial AO7 concentration of 10 mg L-1, an ultrasonic power of 200 W, a catalyst dosage of 1.0 g L-1, and a pH of 3. Moreover, the sonocatalysts demonstrated consistent durability and stability across multiple test cycles. After active species capture experiments and calculation of the energy band, a possible mechanism was proposed based on the special Fenton-like mechanism and the dissociation of H2O2. This research shows that FeNbO4 microspheres can be used as sonocatalysts for the purification of organic wastewater, which has a promising application prospect.

A facile synthesis of K3PMo12O40/WO3 crystals for effective sonocatalytic performance.

Proper treatment of hazardous contaminants in the air, land, and water is crucial to environmental remediation. Sonocatalysis, by using ultrasound and suitable catalysts, has shown its potential in organic pollutant removal. In this work, K3PMo12O40/WO3 sonocatalysts were fabricated via a facile solution method at room temperature. Techniques such as powder X-ray diffraction, scanning electron microscopy (SEM), transmission electron microscopy, and X-ray photoelectron spectroscopy were used to characterize the structure and morphology of the products. By using the K3PMo12O40/WO3 sonocatalyst, an ultrasound-assisted advanced oxidation process has been developed for the catalytic degradation of methyl orange and acid red 88. Almost all dyes were degraded within 120 min of ultrasound baths, proving that the K3PMo12O40/WO3 sonocatalyst has the advantage of speeding up the decomposition of contaminants. The impacts of key parameters, including catalyst dosage, dye concentration, dye pH, and ultrasonic power were evaluated to understand and reach optimized conditions in sonocatalysis. The remarkable performance of K3PMo12O40/WO3 in the sonocatalytic degradation of pollutants provides a new strategy for the application of K3PMo12O40 in sonocatalysis.

High-performance ZnIn2S4/Ni(dmgH)2 for photocatalytic hydrogen evolution: Ion exchange construction, photocorrosion mitigation, and efficiency enhancement by photochromic effect.

In this work, a novel photocatalyst of ZnIn2S4/Ni(dmgH)2 was designed by a simple chemical precipitation method and used to enhance hydrogen evolution under visible light irradiation. Along with vigorous discharges of hydrogen bubbles, an optimal rate of 36.3 mmol/g/h was reached under UV-Vis light for hydrogen evolution, nearly 4.9 times of the one from pure ZnIn2S4. The heterojunction exhibits steady hydrogen evolution capability and owns a high apparent quantum efficiency (AQE) of 20.45% under the monochromatic light at 420 nm. By coupling ZnIn2S4 with Ni(dmgH)2, an extraordinary photochromic phenomenon was detected and attributed to the active Ni-S component in situ formed between the nickel and sulfur composites under light irradiation. The emerging sulfide benefits light absorption of the system and separation of photogenerated electron and hole pairs. Besides providing a promising photocatalyst for visible light hydrogen production, the present work is hoped to inspire new trends of catalytic medium designs and investigations.

Nickel nanoparticle-activated MoS2 for efficient visible light photocatalytic hydrogen evolution.

Direct sunlight-induced water splitting for photocatalytic hydrogen evolution is the dream for an ultimate clean energy source. So far, typical photocatalysts require complicated synthetic processes and barely work without additives or electrolytes. Here, we report the realization of a hydrogen evolution strategy with a novel Ni-Ag-MoS2 ternary nanocatalyst under visible/sun light. Synthesized through an ultrasound-assisted wet method, the composite exhibits stable catalytic activity for long-term hydrogen production from both pure and natural water. A high efficiency of 73 µmol g-1 W-1 h-1 is achieved with only a visible light source and the (MoS2)84Ag10Ni6 catalyst, matching the values of present additive-enriched photocatalysts. Verified by experimental characterizations and first-principles calculations, the enhanced photocatalytic ability is attributed to effective charge migration through the dangling bonds at the Ni-Ag-MoS2 alloy interface and the activation of the MoS2 basal planes.

Facile synthetic routes for photocatalytic Pb3(BTC)2·H2O coordination polymers.

Herein, we report on the successful synthesis of photocatalytic Pb3(BTC)2·H2O polymers via different methods including the surfactant-assisted hydrothermal method, ultrasonic method and reflux method. As the crystal growth is subjected to preparation atmosphere, changes in reaction conditions do not alter the crystal structures of products, but vary their morphology. High ultraviolet-light-driven photocatalytic abilities are attributed to the stable Pb3(BTC)2·H2O, and the effective productions of h+ and ˙OH on the catalysts.

Effective oil-water mixture separation and photocatalytic dye decontamination through nickel-dimethylglyoxime microtubes coated superhydrophobic and superoleophilic films.

Oils and solvable organic pollutants in wastewater demand separations of the components along with efficient photocatalysis in water treatment. Herein, we report on a practical purification strategy by using the multifunctional nickel-dimethylglyoxime [Ni(DMG)2] microtubes to separate the liquid mixture and degrade organic pollutants. The self-assembled [Ni(DMG)2] tubes was synthesized by a facile co-precipitation method. The static contact angle of the film prepared by mixing [Ni(DMG)2] powder (1 : 2 wt%) into polydimethylsilicone (PDMS) to water can reach 161.3°, which can still remain superhydrophobic but oil-friendly under corrosion conditions. PDMS imparts good mechanical properties and serves as both the adhesive and hydrophobic material. PFOTS methanol solution contains a large number of low surface energy groups, which can reduce the surface free energy of [Ni(DMG)2] rough structure. The superhydrophobic rough surface prepared by hollow micron tubular [Ni(DMG)2] samples must have both low surface energy substance and hollow micron tubular morphology. Due to the unique wettability, oil and water were efficiently separated from the oil-water mixture through the films. The coated film itself is photocatalytic in degrading quinoline blue, rhodamine B, methyl orange and methylene blue. By using the film's multifunctionality, a practical wastewater treatment was realized via water-oil separation, followed by fast photocatalytic degradation of solvable dyes.

Synthesis of CdS-loaded (CuC10H26N6)3(PW12O40)2 for enhanced photocatalytic degradation of tetracycline under simulated solar light irradiation.

Largely discharged and excreted medical pollutants pose huge threats to ecosystems. However, typical photocatalysts, such as the Keggin-typed H3PW12O40, can hardly degrade these hazards under visible-light due to their broad bandgap and catalytic disability. In this work, the visible light harvesting was enabled by combining macrocyclic coordination compound CuC10H26N6Cl2O8 with H3PW12O40, and the resulting CuPW was loaded with CdS to reach robust catalytic ability to totally detoxify medicines. We prepared the CuPW-CdS composites through a facile precipitation method, and it showed excellent photocatalytic degradation for degrading tetracycline under visible-light irradiation. The (CuC10H26N6)3(PW12O40)2 with 10 wt% load of CdS shows the highest performance and is ∼6 times more efficient than the pure CuPW counterpart. The heterojunctional CuPW-CdS composites promote the separation of electrons and holes, and consequentially enhance photocatalytic activity. Thanks to migration of electrons from CdS to CuPW, the photocorrosion of CdS is prohibited, resulting in a high chemical stability during photocatalysis. In this work we design a new route to the multi-structural composite photocatalysts for practical applications in medical pollutant decontamination.

Loading AgCl@Ag on phosphotungstic acid modified macrocyclic coordination compound: Z-scheme photocatalyst for persistent pollutant degradation and hydrogen evolution.

In this work, Z-scheme photocatalysts of (CuC10H26N6)3(PW12O40)2/AgCl@Ag were designed and realized for effective removal of solvable and insolvable persistent organic pollutants and hydrogen evolution under simulated sunlight. The catalysts were synthesized via a simple hydrothermal-chemical co-precipitation method. Excellent photocatalytic abilities are demonstrated in degradations of persistent pollutant 2,4-Dinitrophenol (DNP) and tetracycline (TC) under simulated sunlight, as well as a high H2 production rate of 19.28 µâ€¯mol g-1 h-1. Through structural, morphological, radical, and electrochemical determinations, the photocatalytic mechanism was studied, and attributed to effective separations of charge carriers between the heterojunctional counterparts of (CuC10H26N6)3(PW12O40)2 and AgCl@Ag.

Preparation of Graphene Oxide-Based Ink for Inkjet Printing.

Fabrication of graphene-based conductive circuits via inkjet printing processes would be very significant, but preparation of graphene inks which can be used in ordinary household inkjet printer is still a challenge. Graphene oxide (GO) is an important graphene derivative with good dispersion properties in water, because it has a lot of oxygen-containing functional groups. In this paper, the relationship between the concentration of GO and the viscosity and surface tension of its dispersion were studied first, GO were prepared by modified Hummers' method. Moreover, the influence of two surfactants-sodium dodecyl sulfate (SDS) and Triton-X100 (TX-100) on viscosity and surface tension of inks were also investigated. It was found that the concentration of GO was 3.9 mg/mL, and the amount of the addition of SDS and TX-100 were 1 mg/mL and 2.5 mg/mL respectively, which can form stable GO-based inks. Finally, the resultant GO-based inks can be printed by home inkjet printer HP-1010 on normal printing paper, flexible polyimide film and thin aluminum foil. It is expected that the development of inkjet printable GO-based inks will decrease the cost of the preparation of graphene electrode/circuits and open up new ways for the application of GO-based thin film and patterns.

MnWO4 nanoparticles as advanced anodes for lithium-ion batteries: F-doped enhanced lithiation/delithiation reversibility and Li-storage properties.

F-Doped MnWO4 nano-particles were synthesized by a one-pot hydrothermal reaction. When evaluated as an electrode material for a Li ion battery, the F-doped nano-MnWO4 delivers a theoretical capacity of 708 mA h g-1 and a long cycle life, as demonstrated by more than 85% capacity retention when cycled for 150 cycles.

Metallic Contact between MoS2 and Ni via Au Nanoglue.

A critical factor for electronics based on inorganic layered crystals stems from the electrical contact mode between the semiconducting crystals and the metal counterparts in the electric circuit. Here, a materials tailoring strategy via nanocomposite decoration is carried out to reach metallic contact between MoS2 matrix and transition metal nanoparticles. Nickel nanoparticles (NiNPs) are successfully joined to the sides of a layered MoS2 crystal through gold nanobuffers, forming semiconducting and magnetic NiNPs@MoS2 complexes. The intrinsic semiconducting property of MoS2 remains unchanged, and it can be lowered to only few layers. Chemical bonding of the Ni to the MoS2 host is verified by synchrotron radiation based photoemission electron microscopy, and further proved by first-principles calculations. Following the system's band alignment, new electron migration channels between metal and the semiconducting side contribute to the metallic contact mechanism, while semiconductor-metal heterojunctions enhance the photocatalytic ability.

Enhanced Li Storage Stability Induced by Locating Sn in Metal-Organic Frameworks.

By locating elemental Sn in an open anionic framework, the particle cracking arising from huge volume expansion of Sn-based anode materials during lithiation/delithiation is alleviated, and the cycling stability is greatly improved. The Sn-based metal-organic framework anode material shows superior cyclic stability, with a capacity retention >92 % (after 200 cycles) and high lithium storage capacity (610 mAh g-1 ).

SbVO4 nanoparticles synthesized via three facile one-pot methods: controllable morphologies and superhydrophobic coatings.

Inert colloidal SbVO4 with special morphologies is promising for practical superhydrophobic coatings. However, its conventional synthesis suffers from harsh preparation conditions, limiting the material applications. Herein, by using K6V10O28·9H2O as a novel vanadium source, SbVO4 nanoparticles were prepared through three different facile methods: hydrothermal method, reflux method and ultrasonic method. The pH values of the reaction environment were tuned as the only variable to shape the final products. Colloidal morphologies can be engineered to microflakes, or amalgamations of nanoparticles. Drop-casting glasses with the as-synthesized samples will lead to surface superhydrophobicity under basic, neutral, and acidic conditions. Static contact angle of as-coated film can reach above 160° and be durable even under salt solution of different pH values. Besides creating anticorrosive and hydrophobic coating materials, these facile synthesis routes may also facilitate large-scale manufacture of similar chemicals for practical applications.

Nanosecond laser coloration on stainless steel surface.

In this work, we present laser coloration on 304 stainless steel using nanosecond laser. Surface modifications are tuned by adjusting laser parameters of scanning speed, repetition rate, and pulse width. A comprehensive study of the physical mechanism leading to the appearance is presented. Microscopic patterns are measured and employed as input to simulate light-matter interferences, while chemical states and crystal structures of composites to figure out intrinsic colors. Quantitative analysis clarifies the final colors and RGB values are the combinations of structural colors and intrinsic colors from the oxidized pigments, with the latter dominating. Therefore, the engineering and scientific insights of nanosecond laser coloration highlight large-scale utilization of the present route for colorful and resistant steels.

Transition Metal Adsorbed-Doped ZnO Monolayer: 2D Dilute Magnetic Semiconductor, Magnetic Mechanism, and Beyond 2D.

As an improvement over organic or inorganic layered crystals, the synthetic monolayer ZnO(M) inherits semiconductivity and hostability from its bulk, yet it acts as a promising host for dilute magnetic semiconductors. Here, we report the electronic and magnetic properties of ZnO(M) doped with one 3d transition metal ion and simultaneously adsorbed with another 3d transition metal ion. Two sequences are studied, one where the dopant is fixed to Mn and the adsorbate is varied from Sc to Zn and another where the dopant and adsorbate are reversed. First-principles results show that the stable adsorbed-doped systems possess a lower bandgap energy than that of the host. System magnetic moments can be tuned to |5 - x|µB, where x refers to the magnetic moment of the individual 3d atom. An interplay between superexchange and direct exchange yields a ferromagnetic system dually adsorbed-doped with Mn. In addition to a novel material design route, the magnetic interaction mechanism is found beyond two dimensions, having been identified for its three-dimensional bulk and zero-dimensional cluster counterparts.

Magnetic MoS2 pizzas and sandwiches with Mnn (n = 1-4) cluster toppings and fillings: A first-principles investigation.

The inorganic layered crystal (ILC) MoS2 in low dimensions is considered as one of the most promising and efficient semiconductors. To enable the magnetism and keep intrinsic crystal structures, we carried out a first-principles study of the magnetic and semiconductive monolayer MoS2 adsorbed with the Mnn (n = 1-4) clusters, and bilayer MoS2 intercalated with the same clusters. Geometric optimizations of the Mnn@MoS2 systems show the complexes prefer to have Mnn@MoS2(M) pizza and Mnn@MoS2(B) sandwich forms in the mono- and bi-layered cases, respectively. Introductions of the clusters will enhance complex stabilities, while bonds and charge transfers are found between external Mn clusters and the S atoms in the hosts. The pizzas have medium magnetic moments of 3, 6, 9, 4 µB and sandwiches of 3, 2, 3, 2 µB following the manganese numbers. The pizzas and sandwiches are semiconductors, but with narrower bandgaps compared to their corresponding pristine hosts. Direct bandgaps were found in the Mnn@MoS2(M) (n = 1,4) pizzas, and excitingly in the Mn1@MoS2(B) sandwich. Combining functional clusters to the layered hosts, the present work shows a novel material manipulation strategy to boost semiconductive ILCs applications in magnetics.

High catalytic active palladium nanoparticles gradually discharged from multilayer films to promote Suzuki, Heck and Sonogashira cross coupling reactions.

To improve the catalytic activity and reduce the dosage of noble metal catalysts has attracted much more attention for organic synthetic chemists. We facilely fabricated multilayer films of PEI-(PdCl2/1)n through layer-by-layer (LBL) self-assembly method (PEI=polyethylenmine, 1=2,2',7,7'-tetra(4-pyridyl)-9,9'-spirobifluorene, psf). UV-vis spectroscopy, atomic force microscopy (AFM) and scanning electron microscopy (SEM) were used to monitor the growth of multilayer films. X-ray photoelectron spectroscopy (XPS) proved the palladium and ligand 1 were deposited on the film. The PEI-(PdCl2/1)n multilayer films were used as the cisterns of catalysts to gradually discharge high active catalytic moieties in the Suzuki-Miyaura, Heck and Sonogashira cross-coupling reactions. The Pd-loading was as low as 12.1×10(-6)mol% measured by inductively coupled plasma OES spectrometer (ICP), and gave high yields in the typical reactions of bromobenzenes with phenylboronic acids. The LbL catalyst featured the simplicity of fabrication, high efficiency, reusability, convenient control and no sensitive to air in the reactions.

Surfactant-Free and Controlled Synthesis of Hexagonal CeVO4 Nanoplates: Photocatalytic Activity and Superhydrophobic Property.

Nanomaterials with both superhydrophobic surface properties as well as photocatalytic activities could have important industrial applications. Herein, we synthesized CeVO4 nanocrystals with hexagonal nanoplate structures from the reaction of decavanadate (K6V10O28⋅9 H2O) and CeCl3⋅H2O precursors via a hydrothermal method. This synthetic route has four advantages: 1) the reaction condition is relatively mild, 2) it doesn't need surfactants or templates, 3) it requires no expensive equipment, and 4) products are of higher purity. During synthesis, solution pH, and reaction temperature were found to play important roles in determining the growth process and final morphologies of the CeVO4 products. These products were characterized spectrophotometrically and via scanning and transmission electron microscopy. Furthermore, the wettability of the as-synthesized film CeVO4 nanoplates was studied by measuring water contact angle (CA). The largest CA measured was at 169.5 ° for a glass substrate treated with 0.06 g mL(-1) CeVO4 followed by 2 % 1 H, 1 H, 2 H, 2 H-perfluorodecyltriethoxysilane. Finally, the CeVO4 nanoplates exhibited excellent photocatalytic activity in degradation of rhodamine B (RhB) under UV irradiation and was stable even after repeated cycles of use.

Trace amount Pd(ppm)-catalyzed Sonogashira, Heck and Suzuki cross-coupling reactions based on synergistic interaction with an asymmetric conjugated pyridinespirofluorene.

A multilayer film of (Pd(2+)/)10 was simply fabricated by Pd(ii) and 2-Br-2',7,7'-tri(4-pyridyl)-9,9'-spirobifluorene (, Br-tpsf) through a layer-by-layer self-assembly method. The film loaded on a quartz slide as a catalyst reservoir could gradually release high active catalytic species to promote Sonogashira, Heck and Suzuki cross-coupling reactions, with extremely low Pd-loading of 11.0 × 10(-6) mol% and high catalytic efficiency in EtOH-H2O system.

Photocatalytic degradation of organic dyes by La³âº/Ce³âº-H3PW12O40 under different light irradiation.

New photocatalysts (La(3+)-H3PW12O40 and Ce(3+)-H3PW12O40) were prepared, and the degradation activity of these products was evaluated. These photocatalysts were synthesized by the hydrothermal method assisted by PEG-1000 from the reactions of LaCl3 or CeCl3 and phosphotungstic acid. The prepared catalysts were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), ultraviolet-visible diffuse reflection spectroscopy (UV-vis) and thermal gravimetric analysis (TGA). The catalytic activity of La(3+)-H3PW12O40 and Ce(3+)-H3PW12O40 was evaluated by adopting methyl orange (MO) and Rhodamine B (RhB) as model dyes, and the reaction was carried out under UV- and visible light irradiation.