Facile Preparation Research Articles

Facile preparation of SiC/ZrB2-SiC-Si coatings on Cf/SiC composites for ultrahigh temperature ablation resistance

A slurry method combined with silicon infiltration has good prospects in preparing ZrB2-SiC coatings yet remains a great challenge due to the unevenly distributed ZrB2 and heavily damaged substrate. Here we develop a SiC/ZrB2-SiC-Si bilayer coating on Cf/SiC by the slurry method and low-temperature silicon infiltration. The dense SiC inner layer promotes the interfacial bonding and inhibits the inward infiltration of Si; meanwhile, the liquid-gas co-existing siliconization restrains the ZrB2 aggregation and growth. The resultant coating presents high interfacial bonding of 15.6MPa, can endure 5 ablation cycles for 600s at 1900 °C. Especially, the coated Cf/SiC has high strength retention of 97.3%.

A Green Synthesis of Au-Ag Alloy Nanoparticles using Polydopamine Chemistry: Evaluation of their Anticancer Potency Towards Both MCF-7 Cells and their Cancer Stem Cells Subgroup.

Limited chemotherapy efficacy and cancer stem cells (CSCs)-induced therapeutic resistance are major difficulties for tumour treatment. Adopting more efficient therapies to eliminate bulk-sensitive cancer cells and resistant CSCs is urgently needed. Based on the potential and functional complementarity of gold and silver nanoparticles (AuNPs or AgNPs) on tumour treatment, bimetallic NPs (alloy) have been synthesized to obtain improved or even newly emerging bioactivity from a combination effect. This study reported a facile, green and economical preparation of Au-Ag alloy NPs using biocompatible polydopamine (PDA) as a reductant, capping, stabilizing and hydrophilic agent. These alloy NPs were quasi-spherical with rough surfaces and recorded in diameters of 80 nm. In addition, these alloy NPs showed good water dispersity, stability and photothermal effect. Compared with monometallic counterparts, these alloy NPs demonstrated a dramatically enhanced cytotoxic/pro-apoptotic/necrotic effect towards bulk-sensitive MCF-7 and MDA-MB-231 cells. The underlying mechanism regarding the apoptotic action was associated with a mitochondria-mediated pathway, as evidenced by Au3+/Ag+ mediated Mitochondria damage, ROS generation, DNA fragmentation and upregulation of certain apoptotic-related genes (Bax, P53 and Caspase 3). Attractively, these Au-Ag alloy NPs showed a remarkably improved inhibitory effect on the mammosphere formation capacity of MCF-7 CSCs. All the positive results were attributed to incorporated properties from Au, Ag and PDA, the combination effect of chemotherapy and photothermal therapy and the nano-scaled structure of Au-Ag alloy NPs. In addition, the high biocompatibility of Au-Ag alloy NPs supported them as a good candidate in cancer therapy.

Facile fabrication of amorphous Al/Fe based metal-organic framework as effective heterogeneous fenton catalyst for environmental remediation.

This study presents a facile preparation and durable amorphous Fe and Al-based MOF nanoplate (AlFe-BTC MOFs) catalyst with notable stability in Fenton reactions. Rigorous characterization using XRD, HR-TEM, and BET confirms the amorphous nature of the synthesized AlFe-BTC MOFs, revealing mesopores (3.4nm diameter), a substantial surface area (232 m2/g), and a pore volume of 0.69cc/g. XPS analysis delineates distinct Al2p and Fe2p binding energy values, signifying specific chemical bonding. FE-SEM elemental mapping elucidates the distinctive distribution of Fe and Al within the framework of AlFe-BTC MOFs. In catalytic activity testing, the amorphous AlFe-BTC MOFs exhibited outstanding performance, achieving complete degradation of Methylene blue (MB) dye and 78% TOC removal over 45min of treatment under mild reaction conditions. The catalyst's durability was assessed, revealing about 75% TOC removal and complete dye decomposition over five successive recycles, with less than 1mg/L of Fe and Al leaching. UV-Vis spectra revealed the destruction of MB dye over multiple recycling studies. Based on this finding, the amorphous AlFe-BTC MOF nanoplates emerge as a promising solution for efficient dye removal from industrial wastewater, underscoring their potential in advanced environmental remediation processes.

Wettability-patterned PDMS surface with high adhesion for multifunctional droplet transferring manipulation

Surface adhesion is vital to the capability of precise manipulation of open droplets. However, it is still a great challenge to achieve efficient, large-scale, and cost-effective construction of highly adhesive surface for large-volume droplets manipulation. In this paper, a facile methodology for fabricating a superhydrophobic and highly adhesive polydimethylsiloxane (PDMS) surface is presented for multifunctional droplet transferring. The proposed features can be easily fabricated by PDMS replicating and vapor-phase silanization. The 1500-grit sandpaper was chosen as the optimal template, owing to its superior hydrophobic attributes with an approximate contact angle of 155.1°, a maximum adhesion volume of 38.6 μL, and a minimal residual volume of 0.124 μL. Remarkable stability was also validated with exposure to air for more than 9 weeks or to reagents with pH ranging from 1 to 13. Visually colorimetric detection of Cu2+ is successfully demonstrated on both single-droplet and droplet-array forms after a series of transporting, mixing, and reacting processes between different reagent droplets. The facile preparation and equipment-free platform highlights the potential application in point-of-care testing (POCT).

Amino- and Alkoxybenziodoxoles: Facile Preparation and Use as Arynophiles.

We report here on the facile synthesis of amino- and alkoxy-λ3-iodanes supported by a benziodoxole (BX) template and their use as arynophiles. The amino- and alkoxy-BX derivatives can be readily synthesized by reacting the respective amines or alcohols with chlorobenziodoxole in the presence of a suitable base. Unlike previously known nitrogen- and oxygen-bound iodane compounds, which have primarily been employed as electrophilic group transfer agents or oxidants, the present amino- and alkoxy-BX reagents manifest themselves as nucleophilic amino and alkoxy transfer agents toward arynes. This reactivity leads to the aryne insertion into the N-I(III) or O-I(III) bond to afford ortho-amino- and ortho-alkoxy-arylbenziodoxoles, iodane compounds nontrivial to procure by existing methods. The BX group in these insertion products exhibits excellent leaving group ability, enabling diverse downstream transformations.

Facile Preparation of Gold Nanoparticles Silica Composite Film Embedded in Anodized Aluminium Oxide-Glass Substrate

Thin film based on gold nanoparticles or AuNPs is typically used as catalyst in the industrial processes due to their high stability and good reusability. In this work, a thin AuNPs-silica composite film was fabricated firstly from sol-gel method by mixing gold pyrazolate complex to a medium comprised of ethanol, deionized water, and hydrochloric acid followed by addition of tetrabutyl orthosilicate as silica source. Next, 70 microliters of the sol-gel solution were spin-coated on several type of substrates such as glass, anodized aluminium oxide or AAO, and combination of both to yield gold complex-silica composite film. It was found that gold complex-silica composite film fabricated on combination of both AAO-glass substrate gave the best quality based on its surface thickness, layer uniformity and film brittleness. Later, the film was selected and subjected to thermal hydrogen reduction at 210 degrees Celsius for 2 hours to facilitate the formation of gold nanoparticles to give AuNPs-silica in AAO-glass film. Before the heat treatment, the light-brownish colour of the original gold complex-silica in AAO-glass film in daylight will appear as a pinkish red film under UV light, suggesting the interaction between gold atoms and supported by its luminescence spectrum at 692 nm. Upon heat treatment, the resulting AuNPs-silica in AAO-glass film gave a deep-red colour indicating the successful formation of AuNPs. The presence of AuNPs in the film was further confirmed based on the absorption peak at 545 nm, X-ray diffraction pattern at 38.20 degrees for d111 plane in wide-angle region, transmission electron microscopy images showing a small and sphere shape particles as well as its elemental composition in energy dispersive X-ray analysis. Moreover, scanning electron microscope images also suggested that the AAO pores is fully filled with the composite and is in accordance with its surface roughness study via atomic force microscopy analysis.

Development of Green and Facile Sample Preparation Method for Determination of Seven Neonicotinoids in Fresh Vegetables, and Dissipation and Risk Assessment of Imidacloprid and Dinotefuran.

A facile procedure for extracting and determining seven neonicotinoids was developed. Water was the only extraction solvent without phase separation and cleanup steps. The method was validated according to European Union standards, and the values obtained were compared with the criteria. The accuracy values were between 99.8% (thiamethoxam) and 106.8% (clothianidin) at the spiking levels of 0.01, 0.1, and 1 mg/kg in the tested matrices. The precision as pooled RSD values was ≤6.1% (intra-day) and ≤6.9% (inter-day). The limit of quantification was set and tested at 0.01 mg/kg. The matrix effect was evaluated, and all matrices had a suppressive effect. The matrix of the cucumber was the most effective, with -20.9% for dinotefuran and an average of -9.8% for all compounds, while the tomato matrix had the slightest effect. Real marketed samples were analyzed using the developed and QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) methods; the results were not significantly different. A supervised field trial was conducted in the open field to study the dissipation patterns of imidacloprid and dinotefuran in tomatoes. The dissipation of both compounds followed first-order kinetics. The half-life (T½) values were 3.4 and 2.5 days, with dissipation rates k of 0.2013 and 0.2781 days, respectively. Following the EU-MRL database, the calculated pre-harvest interval (PHI) values were 7 and 14 days for imidacloprid and dinotefuran, respectively, and 3 days for both compounds following Codex Alimentarius regulations. The risk of imidacloprid and dinotefuran residues was estimated from chronic and acute perspectives. The risk factors of dinotefuran were lower than those of imidacloprid. Nonetheless, the highest expected residues of both compounds were below the tolerance limits.

Facile preparation of thermally conductive fiber film by self‐assembling interconnected boron nitride nanosheets for effective thermal interface materials

AbstractBoron nitride (BN) has garnered significant attention for its potential in developing thermally conductive materials owing to its inherent insulating properties and high thermal conductivity. However, achieving high thermal conductivity in bulk materials or 3D structures constructed by BN sheets has remained challenging. In this study, we present a novel approach to design a high‐quality BN fiber using xanthan gum (XG) as a skeleton, aiming to facilitate heat dissipation in integrated circuits. The resulting thermally conductive film, with orderly and compactly arranged BN sheets in the XG skeleton, exhibits a remarkable in‐plane thermal conductivity of 8.26 Wm−1 K−1 and an out‐of‐plane thermal conductivity of 1.35 Wm−1 K−1. This film efficiently enables fast heat dissipation for LED chips and thermoelectric generators. Finite element simulation further supports the efficient heat transfer capacity of the BN fiber films.Highlights A high‐quality BN fiber was prepared by a facile approach. The BN fiber film exhibited high thermal conductivity. This film enables fast heat dissipation in practical applications.

Facile preparation and broadband microwave absorption of multilayered materials based on thin films of reduced graphene oxide

Microwave absorption (MA) materials have received extensive attention for their wide applications in both civil and military areas. However, many MA materials have a large thickness, high filling ratio, and narrow effective microwave absorption bandwidth (Reflection Loss, RL ≤ −10 dB) (EAB), and are prepared by complex processes. In this work, a reduced graphene oxide (RGO) film is prepared for the first time by an approach involving floating-dipping and chemical reduction. Compared with previous micrometers-thick RGO films, the present 200 nm-thick dense RGO film is critical for improving not only the impedance matching but also the capability of the material to attenuate incident microwaves. Based on such a thin RGO film, a multilayered material with a jaaumann structure is constructed with individual RGO layers alternating between low dielectric polyethylene terephthalate (PET) sheets. With the superb impedance matching, multilayer attenuation, and multi-cavity resonance, the present multilayered material can achieve a wide EAB of 13.75 GHz with a minimum reflection loss of −47.69 dB using only 3 layers of RGO films. This study provides a new and simple strategy for the development of layered materials with a thin thickness, low filling ratio, and strong absorption with a wide EAB.

A facile high-efficiency preparation strategy for Al-containing multi-component boride microcrystals with superior comprehensive performance

Multi-component transition group metal borides (MMB2) have become a research hotspot due to their new composition design concepts and superior properties compared with conventional ceramics. Most of the current methods, however, are complicated and time-consuming, the mass production remains a challenge. Herein, we proposed a new high-efficiency strategy for synthesis of MMB2 using molten aluminum as the medium for the first time. The prepared Al-containing multi-component borides (TiZrHfNbTa)B2 microcrystals had a homogeneous composition with a hexagonal AlB2 structure and ultra-high hardness value of ∼35.3 GPa, which was much higher than data reported in the literature and the rule of mixture estimations. Furthermore, combined with the First-principles calculation results, we found that the Poisson's ratio (v) values exhibit a clearly ascending trend from 0.17 at VEC = 3.5 to 0.18 at VEC = 3.4, then to 0.201 at VEC = 3.2 with the increasing of Al content. This indicates that the intrinsic toughness of multi-component boride microcrystals is obviously enhanced by the trace-doped Al elements. Besides, the fabricated Al-containing multi-component boride microcrystals have superior oxidation activation energy and structural stability. The enhanced oxidation resistance is mainly attributed to the formation of a protective Al2O3 oxide layer and the lattice distortion, both of which lead to sluggish diffusion of O2. These findings propose a new unexplored avenue for the fabrication of MMB2 materials with superior comprehensive performance including ultra-hardness and intrinsically improved thermo-mechanical properties.

Waste to worth: Facile preparation of CaO2 derived from oyster shells for highly efficient degradation of organic contaminants based on Fenton-like system

In recent years, CaO2 has been frequently used as a substitute for H2O2 to address the limitations of H2O2. However, commercially available CaO2 are facing the shortcomings of low purity and limited preparation conditions. Oyster shells can provide superior and abundant biomass calcium element with low cost for developing CaO2. In this work, highly purified CaO2 functional biomaterials were prepared via a facile approach derived from waste oyster shells, which were applied in a Fenton-like system to remove organic pollutants. Experimental results indicated that the oyster shells-derived CaO2 with 100% purity exhibited a greatly enhanced catalytic performance compared with other CaO2 materials in Fenton-like catalytic degradation of organic pollutants, which can be completely removed within 60 s. The high purity of CaO2 would facilitate the release of H2O2 during the Fenton-like catalytic reaction and promote the generation of more active species to oxidize pollutants. Besides, the abundant trace metal elements originated from oyster shells can further motivate the Fenton-like reaction and accelerate the degradation of pollutants, endowing oyster shells-derived CaO2 an excellent catalytic activity. Furthermore, the Fenton-like catalytic mechanism was proposed on basis of tests of radicals trapping and electron spin resonance, validating the vital roles of ⋅OH, ⋅O2– and 1O2 generated throughout the reaction process. This work not only provides a novel and low-cost approach to exploit CaO2 with highly efficient catalytic ability, but also realizes the effective resource utilization of waste shells.

Amine-Functionalized Meso-Macroporous Polymers for Efficient CO2 Capture from Ambient Air.

Over the past decade, direct air capture (DAC) of carbon dioxide (CO2) using solid nanoadsorbents has garnered attention as a negative emission technology with high energy efficiency. Although operational, the large-scale deployment of DAC technologies has been significantly delayed due to the low performance and high cost of solid DAC nanoadsorbents. Herein, we present a novel family of meso-macroporous melamine formaldehyde (MF) materials with a facile preparation methodology, low capital cost, and unique physicochemical characteristics for DAC. The fabricated MF materials exhibit an extra-large pore volume of 5.19 cm3/g with a 24.6 nm average pore diameter. We show that the synthesized MF materials can be used as substrates and impregnated with different amounts of tetraethylenepentamine (TEPA) to act as chemical nanoadsorbents for DAC. Owing to the ultrahigh pore volume of MF, a substantial amount of 71 wt % TEPA (i.e., MF-TEPA71%) can be loaded, resulting in 2.65 mmol/g of CO2 uptake under DAC conditions. In addition, the superior physicochemical properties of MF lead to a high CO2 loading of 2.07 mmol/g with low TEPA loading in MF-TEPA33%. The prepared MF-TEPA nanoadsorbents can be successfully employed in different shapes (i.e., droplets, pellets, and coatings) and maintain their superiority across different temperatures and CO2 concentrations. This study provides a promising approach for developing meso-macroporous substrates through a straightforward and scalable synthesis method, representing a new avenue for the next generation of DAC nanoadsorbents with superior performance for practical applications.

Iridescent transparent passive radiative cooling enabled by cellulose nanocrystal assemblies

Recently, passive daytime radiative cooling (PDRC) materials that reflect sunlight and transmit heat through atmospheric transparent windows to outer space without any energy consumption have attracted broad interest. However, most PDRC materials have the complicated structures, white or mirror-like appearance with poor transparency. Here, we reported a transparent iridescent PDRC coating material constructed by the evaporation-induced self-assembly (EISA) of cellulose nanocrystals (CNCs). The iridescent PDRC coating not only shows high light transparency (75 %) because the right-handed circularly polarized light can transmit the unique left-handed chiral nematic liquid crystal structure, but also shows high solar reflection efficiency (95.2 %) and infrared emission efficiency (96.5 %) that endows the coating with high radiative cooling efficiency (119 W/m2). More importantly, the PDRC coating can apply on polymethyl methacrylate (PMMA), polyethylene terephthalate (PET) film and textiles, and the substrate color has no negative impact for cooling. With the excellent radiative cooling efficiency, high transparency, facile preparation process and general applicability, the CNCs-based PDRC coating opens a new pathway toward the potential application of PDRC for environmental sustainability purpose.

Amorphous-crystalline transition-driven synthesis of Co single-atom catalysts on MoO3 for enhanced hydrogen evolution in acidic and alkaline media

Single atom catalysts (SACs) dispersed in metal oxide supports offer not only maximized catalyst utilization but also extended modulation capabilities through interactions between the SA and its support. However, achieving facile preparation and ensuring electrochemical durability of such SACs, particularly for hydrogen evolution reaction (HER) applications, remain formidable challenges. Our study addresses these issues by employing an amorphous-to-crystalline phase transition in MoO3 to synthesize a cobalt (Co) SA catalyst. This method facilitates the production of highly selective SA catalysts at low temperatures and ensures their enhanced stability in HER applications. The Co SA MoO3 catalyst exhibits superior performance in HER, operating effectively in both acidic and alkaline environments. Significantly, it maintains stable HER activity across these diverse electrolytic conditions. Our Density Functional Theory (DFT) calculations provide insights into the exceptional HER performance of Co SA MoO3. These calculations reveal that the strong affinity for hydrogen and water, facilitated by the modulation of the p-band orbitals at specific oxygen sites adjacent to the Co SA, establishes a thermoneutral pathway for HER. This study represents a pivotal advancement, showcasing a highly practical and robust single-atom catalyst, marking a significant stride towards sustainable energy solutions.

Facile Heck coupling synthesis and characterization of a novel tris(4-(pyridine-4-vinyl)phenyl)methylsilane tridentate core

Aromatic rigid ligands with carboxylate, phosphate, or pyridyl terminals are highly important today for application in the manufacturing of metal-organic frameworks (MOFs), covalent organic frameworks (COFs), and other supramolecular structures. Aromatic rigid ligands give rigidity to MOFs and COFs materials. In addition, building units are important in that their judicious selection can result in a 2-D or 3-D framework with moderate or high surface area. Most aromatic linkers are based on carbon centres which are associated with a negative impact on the environment. However, in contrast, silicon-based centres are scarce and benign to the environment, even though they can be prepared facilely via metathesis. Here, we report the facile preparation of a new tris (4-(pyridine-4-vinyl)phenyl) methylsilane using the classical Heck coupling reaction. The bridging ligand was synthesized via the standard Heck coupling of 4-vinylpyridine with tris(4-bromophenyl)(methyl)silane.

Core‐shell TiO2@Au Nanofibers Derived from a Unique Physical Coating Strategy for Excellent Capacitive Energy Storage Nanocomposites

AbstractPolymer dielectrics have been widely employed in pulsed power systems, but their applications are severely restricted by the low energy density. Incorporating core‐shell nanofillers is one promising strategy to enhance the energy density of polymer dielectrics. Nowadays, core‐shell nanofillers are mainly prepared via chemical coating strategies, which always involve complex chemical synthesis procedures. Herein, a unique physical coating strategy is developed to prepare core‐shell TiO2@Au nanofibers consisting of monodispersed Au nanoparticles homogeneously anchored on the TiO2 nanofibers. Interestingly, the TiO2@Au nanofibers show outstanding dielectric energy storage boosting capability. Specifically, with merely introducing 0.1 wt.% TiO2@Au nanofillers, the TiO2@Au/PVDF composite exhibits a substantially enhanced breakdown strength of 749 MV m−1, which reaches 152.8% of PVDF. Meanwhile, a high dielectric constant of 10.2 (114.1% of PVDF) is obtained. Consequently, an ultrahigh energy density of 18.6 J cm−3, which is 250.1% of PVDF, is achieved. It is further revealed that the significant energy storage boosting effect is originated from the Coulomb blockade and micro‐capacitor effects of the TiO2@Au nanofibers. This work establishes a unique paradigm for the facile preparation of core‐shell nanomaterials, which have huge potential for both dielectric energy storage and other functional nanocomposites.

Hollow-structured cobalt sulfide electrocatalyst for alkaline oxygen evolution reaction: Rational tuning of electronic structure using iron and fluorine dual-doping strategy

Utilizing renewable electricity for water electrolysis offers a promising way for generating high-purity hydrogen gases while mitigating the emission of environmental pollutants. To realize the water electrolysis, it is necessary to develop highly active and precious metal-free electrocatalyst for oxygen evolution reaction (OER) which incurs significant overpotential due to its complicated four-electron transfer mechanism. Hence, we propose a facile preparation method for hollow-structured Fe and F dual-doped CoS2 nanosphere (Fe-CoS2-F) as an efficient OER electrocatalyst. The uniform hollow and porous structure of Fe-CoS2-F enlarge the specific surface area and increase the number of exposed active sites. Furthermore, the Fe and F dual-dopants synergistically contributed to the adjustment of electronic structure, thereby promoting the adsorption/desorption of oxygen-containing reaction intermediates on active sites during the alkaline OER procedure. As a result, the prepared Fe-CoS2-F exhibits outstanding OER activity, characterized by a low overpotential of 298 mV to achieve a current density of 10 mA cm−2 and a Tafel slope as small as 46.0 mV dec−1. Based on computational theoretical calculations, the introduction of the dual-dopants into CoS2 structure reduce the excessively strong adsorption energy of reaction intermediate in the rate determining step, leading to effectively promoted electrocatalytic cycle for OER in alkaline environment. This study presents an effective strategy for preparing noble metal-free OER electrocatalysts with promising potential for large-scale industrial water electrolysis.

Medium-entropy alloy MoCoCu-P as an efficient bifunctional catalyst for water splitting

Medium/high-entropy alloy (MEA/HEA) catalysts have emerged as ideal candidates as multi-functional catalysts owing to their synergistic effects of multiple metal components on the boosted catalytic activity. However, the facile preparation and screening of suitable MEAs element to achieve high catalytic performance still remain challenging. In this work, we successfully synthesized a MoCoCu-P MEA electrocatalyst for water splitting electrocatalysis through a feasible electrodeposition method. The as-prepared MEA demonstrated an overpotential of 276.1 mV (j=10 mA/cm²) for OER with a Tafel slope of 38.3 mV/dec, coupled with an overpotential of 64.7 mV for HER (j=10 mA/cm²) with a Tafel slope of 87.7 mV/dec. Employed in an overall water electrolysis cell, MEA achieved a nearly 100% Faradaic efficiency and superior stability over than 50 hours at a high current density of 50 mA/cm2. X-ray photoelectron spectroscopy (XPS) analysis verify that high-valence Co and Mo are the most active sites for OER, while electron-rich Cu at the presence of P is responsible for the boosted HER in the MoCoCu-P MEA. This study not only provides a feasible electrodeposition strategy to obtain MEA catalysts with high activity and excellent stability, but also sheds fundamental lights on the identification of the active sites in MEA catalysis.

Facile green preparation of Y2O3 decorated with ZnFe2O4 using citrus limon (L.) osbeck leaf extract for photocatalytic degradation of malachite green

The Y2O3 decorated with ZnFe2O4 was successfully synthesized using Citrus limon (L.) Osbeck leaf extract for the first time. A modification of Y2O3 with ZnFe2O4 nanoparticles was carried out because Y2O3 is stable but has a wide band gap, making it less active in visible light. On the other hand, ZnFe2O4 has a small band gap and is cheap. The synthesized ZnFe2O4/Y2O3 nanocomposites, ZnFe2O4, and Y2O3 nanoparticles were characterized using FTIR, XRD, TEM, SEM, and DRS UV–Vis. TEM and DRS UV–Vis results show that the ZnFe2O4/Y2O3 nanocomposite particle has a size of 49,61 nm with a unique shape and an optical band gap of 2.08 eV. The photocatalytic activity of Y2O3, ZnFe2O4, and ZnFe2O4/Y2O3 was observed based on the photodegradation of malachite green (MG) dye under visible light. The results demonstrate that ZnFe2O4/Y2O3 can degrade MG with a photodegradation percentage of 95 % within 120 min, which is better than pure ZnFe2O4 and Y2O3. After the fourth cycle, the photodegradation percentage of MG by ZnFe2O4/Y2O3 remained at 88 %, demonstrating good reusability of ZnFe2O4/Y2O3 for photocatalytic degradation. These findings demonstrate that the use of ZnFe2O4 as a modifier may increase the photocatalytic performance of Y2O3.

Preparation of robust superhydrophobic surface on PET substrate using Box-Behnken design and facile sanding method with PTFE powder

Superhydrophobic surfaces have attracted increasing interests due to their excellent features, while achieving facile preparation of superhydrophobic surface with good mechanical stability is still a challenging work. In this paper, we prepared a superhydrophobic surface by sanding polytetrafluoroethylene powder directly onto the surface of a polyethylene terephthalate (PET) film by means of a simple sanding method with sandpaper. The fabrication parameters were firstly optimized using response surface methodology. Surface morphology and chemical composition of the fabricated surface were characterized by field emission scanning electron microscopy, Fourier transform infrared and x-ray photoelectron spectroscopy. The mechanical performance of the superhydrophobic PET surfaces was evaluated by tape peeling test, and potential applications of this surface in self-cleaning and anti-icing were finally carried out. The results showed that the water contact angle up to 153.5° and sliding angle less than ∼3° on PET surface could be prepared under the optimum conditions, and its superhydrophobicity of surfaces was attributed to the synergistically effect of low surface energy and surface roughness. The fabricated superhydrophobic surfaces also exhibited good resistance to abrasion, and they have great potential for application in the fields of self-cleaning and anti-icing.