37 research outputs found
A facile synthesis of K₃PMo₁₂O₄₀/WO₃ crystals for effective sonocatalytic performance
Abstract
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
Abstract
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
Excellent photo- and sono- catalytic BiOF/Bi₂O₃ heterojunction nanoflakes synthesized via pH-dependent and ionic liquid assisted solvothermal method
Abstract
Herein, a series of BiOF/Bi₂O₃ heterojunction nanoflakes were designed. The XRD and TEM confirm that the phase structure and morphology of BiOF/Bi₂O₃ were affected by the pH value of the precursors. The catalytic activities were investigated in different catalytic ways including photocatalytic activity under ultraviolet light, photocatalytic activity under visible light and sonocatalytic activity under ultrasonic irradiation. It concluded that the catalytic performances of BiOF/Bi₂O₃ are substantially affected by laboratorial pH values. The BiOF/Bi₂O₃ prepared at lower pH values exhibited enhanced catalytic activity attributed to the favorable morphology and band gap energy. Meanwhile, it shows excellent sonocatalytic performances due to the synergistic effect of BiOF/Bi₂O₃ and H₂O₂ in sonocatalytic process. The sonodegradation efficiencies of rhodamine B reaches 95.28 % in the presence of three drops of H₂O₂ within 10 min of ultrasonic irradiation. The catalytic mechanism reveals that ·OH as the dominant active specie plays a key role in degrading the dyes both under UV light illumination and ultrasonic irradiation
Coating polyurethane sponge with Dy-MOF for efficient oil–water separation in complex environments
Abstract
Leakage of industrial oil and organic solvents seriously harms environment and ecology yet demanding highly efficient and durable materials for oil–water separations. In this work, ultra-light and highly flexible polyurethane (PU) sponges were engineered to 3D oil–water separators by coating the dysprosium metal organic framework (Dy-MOF) onto the surfaces of the PU frames. Through a facile impregnation, the Dy-MOF was attached to the full frames of the sponges. Consequently, liquid contact surfaces were extended from these on top layers to the whole rack. Superhydrophobicity with water contact angles up to 152.08° and lipophilicity enable continuous separations of dichloromethane from water through the resulted Dy-MOF@PU sponges in a continuous mode. The modified sponges own high gravimetric absorption capacities for oil and organic solvents, and high resistances to temperature variations, corrosive solutions, and mechanical abrasions, thanks to the well-connected and stable superhydrophobic/supportive interfaces. An efficient separation was successfully piloted for oily wastewater consisting of water-in-oil emulsions stabilized by surfactants, demonstrating the potential of practical water treatment of Dy-MOF@PU in complex environments. Mechanism leading to superior oil–water separation capability was studied and inferred as the combined effects of the physical and chemical properties arisen from the stable Dy-MOF and flexible but porous matrix
Loading AgCl@Ag on phosphotungstic acid modified macrocyclic coordination compound:Z-scheme photocatalyst for persistent pollutant degradation and hydrogen evolution
Abstract
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 μ 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
Formation of BaF₂ microcrystals as superhydrophobic materials via a hydrothermal method
Abstract
Controllable BaF₂ microcrystals with super-hydrophobic property have been successfully synthesized via a facile hydrothermal process. XRD, SEM and CA were used to study the structure, morphology and the hydrophobic properties of the BaF₂ materials. The effects of reaction time, surfactants and pH were investigated in order to get a series of accurate reaction conditions for the preparation of BaF₂ material. The results showed that uniform BaF₂ cubic phase structure was fabricated when the reaction temperature was controlled at 160 °C for 24 h. In addition, the BaF₂ materials showed excellent super-hydrophobic properties. The results of the influence of time and substrates exhibited that the sample could maintain the stable super-hydrophobic property for over 10 days. As a promising superhydrophobic material, the studies of BaF₂ reported in this paper have potential application prospect and have a certain guiding meaning for the future study about superhydrophobic materials
Shape-controlled hydrothermal synthesis of superhydrophobic and superoleophilic BaMnF₄ micro/nanostructures
Abstract
In this paper, we focus on the controllable synthesis of BaMnF₄ micro/nanostructures via a facile one-step hydrothermal method assisted by different surfactants. The chemical structure, morphology and superhydrophobic properties have been studied by XRD, SEM, TEM, EDS and CA. The results show that the pH of the starting solution, temperature, reaction time, and surfactant affect the crystallinity, morphology and superhydrophobic properties of the products. The preliminary reaction path and formation mechanisms of the BaMnF₄ with different shapes are also investigated. To the best of our knowledge, the present synthesis route is novel. Furthermore, the as-prepared BaMnF₄ surface shows superhydrophobicity and superoleophilicity
Impacts of ionic liquid capping on the morphology and photocatalytic performance of SbPO₄ crystals
Abstract
By using [BMIM][PO₄] as a coupling agent, a novel hydrothermal method is developed to prepare microspherical SbPO₄ with different morphologies and photocatalytic abilities. An evolution from flower- to sphere-shaped products was observed. Regular SbPO₄ microspheres with diameters of 10–35 μm were found to exhibit excellent photocatalytic properties to degrade rhodamine B (45 min, 99%) and methylene blue (60 min, 99%) under UV light irradiation. The impacts of the ionic liquid type, capping abilities and reaction conditions on final products were revealed. It is found that by tuning the reaction time and temperature, [BMIM][PO₄] can gradually react with SbCl₃, forming SbPO₄ products with a controllable morphology and a tailored bandgap. The distinguished photocatalytic abilities are attributed to the large surface area and low bandgap energy of the semiconductor
A facile hydrothermal preparation of O-deficient BiNbO₄ nanorods for effective sonocatalytic decontamination
Abstract
Niobium oxalate was employed to obtain BiNbO₄ for the first time and the BiNbO₄ nanorods were successfully synthesized through a hydrothermal method at a low temperature. Oxygen vacancies were introduced into the BiNbO₄ nanorods, lowering the BiNbO₄ bandgap. The O-deficient BiNbO₄ exhibited excellent sonocatalytic performance
One-pot hydrothermal synthesis of ZnC₄O₄ concave microspheres with superhydrophobic and superoleophilic properties
Abstract
In this study, we report a facile solution route to prepare superhydrophobic and superoleophilic ZnC₄O₄ concave microspheres. The surface morphologies and chemical compositions were determined through scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDX), X-ray powder diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The wettability of the as-synthesized ZnC₄O₄ coordination compound surface was studied by measuring the contact angle (CA). A static CA for water over 160° was observed, which was closely related to both the structure and chemical modification of ZnC₄O₄, and a 0° static CA for octane was observed, which showed that the as-prepared ZnC₄O₄ surface had superoleophilic properties. Furthermore, the as-prepared ZnC₄O₄ surface showed superhydrophobicity for some corrosive liquids, such as acidic and basic aqueous solutions