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A new type of composite photocatalyst, BiVO 4 /α-Fe 2 O 3 , was successfully prepared by using hydrothermal-calcinations method and the catalysts were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), UV–Vis reflection spectrometer (DRS), X-ray photoelectron spectroscopy (XPS), and N 2 adsorption–desorption measurement (BET), respectively. It was displayed that the α-Fe 2 O 3 had no effect on the crystal phases of BiVO 4 but obviously enhanced the photocatalytic activity of the BiVO 4 . The composite α-FeOOH/BiVO 4 with the mass ratio of 5:5 and the calcinations of 350 °C had the highest photocatalytic activity. The degradation rate of benzene was up to 66.87% when initial benzene concentration was 100 mg/m 3 and after 365 nm UV irradiation 210 min O 2 − and h + played a key role in the photo-degradation of benzene, and the enhanced performance of BiVO 4 /α-Fe 2 O 3 composite could be attributed to the synergistic effect between α-Fe 2 O 3 and BiVO 4 . [ABSTRACT FROM AUTHOR]

[Display omitted] • Benzene has larger adsorption energies on Ni-X (X = Y, Cd, Sc, Lu, Ag, Ti, Hg, Pd, Zn, V, Cu, and Au) than the undoped case. • The SCE ML models suggest that the size, electronegativity, and valence are critical to adsorption. • The adsorption energies of a C 2 H 2 on the M-X surfaces exhibit the parabolic relationship with electronegativity of the doping elements. • An "add and dehydrogenate" mechanism was proposed to describe the initial growth of nanocarbon with hydrocarbon precursors. To understand the effects of H of hydrocarbon precursors and alloying elements of catalysts on the initial growth of carbon nanomaterials, this work combined first-principles (FP) calculation and machine learning (ML) methods to study the adsorption of complete hydrocarbon molecules on various alloy surfaces. Specifically, we calculated the energetics and geometries of the adsorption of acetylene (C 2 H 2) molecules on the pristine Ni, Co, and Fe metal and a benzene molecule on Ni-X [X = thirty 3d, 4d, and 5d transition metal (TM) elements] alloy surfaces. The results suggest that benzene has larger adsorption energies on Ni-X (X = Y, Cd, Sc, Lu, Ag, Ti, Hg, Pd, Zn, V, Cu, and Au) than that on the pristine Ni surface. Furthermore, the ML models were constructed using the surface "Center-Environment" (SCE) features to predict the FP results. The ML models suggest that the features critical to adsorption energies include the size, electronegativity, and valence of the doping element. We proposed an "add and dehydrogenate" mechanism underlying the initial growth of nanocarbon with hydrocarbon precursors. These results provide a theoretical basis in the design of alloy catalysts including in-plane single atom catalysts. [ABSTRACT FROM AUTHOR]

Highlights: [•] Switchable superoleophilicity and high oleophobicity surfaces were prepared. [•] The tunable wettability was realized by reversing the feeding order of the perfluorinated monomer. [•] Distribution of low surface energy groups played a key role in determining surface oleophobicity. [•] The switchable surfaces can be used to control over oil permeation without any stimulation. [ABSTRACT FROM AUTHOR]

Abstract A layer of platinum was fabricated through electroplating on the surface of NiCoCrAl model alloy. Diffusion characteristics and oxidation behaviour of Pt-coated NiCoCrAl compared to uncoated was investigated at 1050 °C. The platinum inter-diffusion layer within the alloy was obtained through the heat treatment. For microstructural characterization results of scanning electron microscopy were combined with X-ray diffraction data. Due to different covalent bonding calculated by first principle calculation, the platinum presented different diffusion abilities in β-NiAl and γ′-Ni 3 Al phases during the heat treatment. The calculated elastic constant and elastic moduli revealed that Pt-doped β-NiAl and γ′-Ni 3 Al possess better elastic and mechanical properties than β-NiAl and γ′-Ni 3 Al. The platinum addition restrained the spallation of Ni-rich oxide on Pt-coated NiCoCrAl alloy compared to uncoated, hence the adhesion between the oxide layer and NiCoCrAl alloy was improved. Highlights • Pt obviously increases Al 2 O 3 scale adhesion at early stage of the oxidation. • Pt increases the elastic stability and mechanical strength of β-NiAl and γ′-Ni 3 Al. • Pt has different diffusion ability in β-NiAl/γ′-Ni 3 Al phases within the alloy. • Weak covalent bonding confirms easier Pt diffusion within β-NiAl than γ′-Ni 3 Al. [ABSTRACT FROM AUTHOR]

A novel fiber-optic hydrogen sulfide sensor based on a thin-core Mach-Zehnder fiber modal interferometer (TMZFI) is demonstrated and fabricated. This in-line interferometer is composed of a short section of thin-core fiber sandwiched between two standard single mode fibers, and the fast response to hydrogen sulfide is achieved via the construction of tungsten sulfide film on the outside surface of the TMZFI using the dip-coating and calcination technique. The fabricated sensing nanofilm is characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), high resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS) spectrometer, Fourier transform infrared (FTIR) and spectroscopic analysis technology, etc. Experimental results showed that the WS 2 sensing film has a hexagonal structure with a compact and porous morphology. The XPS and FTIR indicate that the existence of two elements (W and S) is demonstrated. With the increasing concentration of hydrogen sulfide, the interference spectra appear blue shift. In addition, a high sensitivity of 18.37 pm/ppm and a good linear relationship are obtained within a measurement range from 0 to 80 ppm. In addition, there is an excellent selectivity for H 2 S, which has also been proved by the surface adsorption energy results of tungsten sulfide with four gases (H 2 S, N 2 , O 2 and CO 2 ) by using the density functional theory calculations. This interferometer has the advantages of simple structure, high sensitivity and easy manufacture, and could be used in the safety monitoring field of hydrogen sulfide gas. [ABSTRACT FROM AUTHOR]

Recently, considerable efforts have been made on superhydrophobic–superoleophilic filter to satisfy the requirements of the applications to oil/water separation. In this work, we obtained a superhydrophobic and superoleophilic film by coating cured fluoropolymer@silica hybrid on stainless steel mesh. Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS) and thermogravimetric-differential scanning calorimetry (TG-DSC) were used to determine the chemical composition and thermal stability of the sample. The effect of silica nanoparticles (NPs) concentration on the surface property of the hybrid film was analyzed by scanning electron microscopy (SEM), atomic force microscopy (AFM) and contact angle analyzer. The results indicate that silica NPs not only enhance the thermal stability, but also strengthen the hydrophobicity and oleophilicity of the film. When 20 wt% silica NPs was added into the thermosetting fluoropolymer, the hybrid film shows both superhydrophobicity and superoleophilicity owing to the large surface roughness factor (RMS) and porous structure. Moreover, the hybrid film could be used to separate water from different oils effectively. When the pore size of the mesh is less than 300 μm, the oil/water separation efficiency of the film reaches above 99%, which shows a great potential application to dehydrate fuel oils. [ABSTRACT FROM AUTHOR]

A new method was proposed to create a superamphiphobic surface with high and durable liquid repellency by effortlessly one-step spraying the fluorinated nanoparticles onto the polymer paper. Even 90 vol% ethanol solution could keep the Cassie state on the surface. This work opens a new avenue for accomplishing the long-sort task of efficiently fabricating flexible superamphiphobic surfaces with high comprehensive performances. [Display omitted] • Superamphiphobic papers were prepared via one-step spraying in several minutes. • Various polar, non-polar, and corrosive liquids kept the Cassie state on the papers. • The papers exhibit high robustness for resisting underwater ultrasonic shock. • The papers could be used for oil self-cleaning and droplet-based analysis platforms. Flexible superamphiphobic surfaces show significant potential in anti-fouling, flexible electronics, droplet-based microfluidics, etc. However, there is a bottleneck in quickly generating pliable superamphiphobic surfaces with high liquid repellency and practicability. Here, a new method was proposed to create a superamphiphobic surface with high and durable liquid repellency by effortlessly one-step spraying the fluorinated TiO 2 nanoparticles onto the polymer paper. Even 90 vol% ethanol solution could keep the Cassie state on the surface. The adhesion strengthening of the nanoparticles agglomerates on the paper's wires generated excellent robustness for resisting underwater ultrasonic shock, resulting in a failure time 2000-times longer than the smooth substrate. No significant degeneration of the paper was observed after storing for 90 days, bending for 1000 cycles, or heating at 200 °C. Because of the attractive figurability, the paper could quickly fit on curved surfaces or internal walls. As a proof of concept, the superamphiphobic paper was successfully used for deformable anti-corrosion shelter and droplet-based analysis platform. This work opens a new avenue for accomplishing the long-sort task of efficiently fabricating flexible superamphiphobic surfaces with high comprehensive performances. [ABSTRACT FROM AUTHOR]

[Display omitted] • TMA prefers to insert between the amine ligands and PeQDs rather than kick the ligands out. • The adsorption and demethylation of TMA induce obvious trap states on the PeQDs surface. • MADI suppresses the over-dissociation of the precursor and obtains trap-free electronic structure on ligands-capped PeQDs. Water and oxygen stability has been one of the major bottlenecks in practical application of perovskite quantum dots (PeQDs). Recently, ultra-thin alumina via atomic layer deposition (ALD) has been used as protective coating to improve the stability of PeQDs. However, the use of organo-metallic trimethylaluminum (TMA) precursor is typically accompanied by undesirable photoluminescence quenching of PeQDs. We investigate in detail the interaction mechanism between TMA and amine ligands-capped PeQDs to shed light on the origin of such quenching. First-principles calculations reveal that TMA is highly reactive to insert into amine ligands and PeQDs, which disrupts the bonding between ligand and the PeQDs surface. The demethylation of the insertion product would induce substantial trap states on the PeQDs surface, resulting in the degradation of photoluminescence. Methyl aluminum diisopropoxide (MADI) with asymmetric structure is proposed as an ALD precursor for the treatment of PeQDs. Due to the tight binding of the isopropyl groups to the Al atom, MADI can effectively avoid successive dissociation after reaction with surface ligands, avoiding the formation of trap states. This work highlights the importance of precursor engineering for ligand passivation and provides guidance to the design of precursors with minimal trap-states for highly efficient and stable PeQDs. [ABSTRACT FROM AUTHOR]

[Display omitted] • First principles calculation and microkinetic analysis are performed to study NO oxidation properties of pristine and 3d transition metal doped ZnMn 2 O 4. • The catalytic mechanisms of NO oxidation on pristine and B-site doped ZnMn 2 O 4 are proposed. • Cu, Fe, Zn, Ti, Cr and Ni doping can effectively promote the reaction rates of NO oxidation and especially Cu and Fe doped ZnMn 2 O 4 outperform than others. • A general relation between NO oxidation reactivity and NO adsorption energies is proposed and the suitable first and second NO adsorption energies are −2.4 ∼ −2.0 eV and −1.50 ∼ −0.25 eV, respectively. A highly-efficient NO oxidation catalyst is urgently needed due to serious NO pollution. Herein, we perform first principles calculations and microkinetic analysis to investigate NO oxidation properties of pristine and 3 d transition metal doped ZnMn 2 O 4 that exhibits similar Mn-Mn dimer features to SmMn 2 O 5. It is found that two different categories of NO oxidation mechanism with different O 2 adsorption and dissociation behaviors occur on pristine and B-site doped ZnMn 2 O 4. The microkinetic analysis shows that Cu, Fe, Zn, Ti, Cr and Ni doping can effectively promote the reaction rates of NO oxidation, with Cu and Fe doped ZnMn 2 O 4 showing the best low-temperature NO oxidation performance. Sc, V, and Co doping are predicted not to be beneficial to performance enhancement. A general relation between NO oxidation reactivity and NO adsorption energies is proposed to quantitatively depict the key factors influencing NO oxidation performance. The relation provides a specific strategy for the optimization of NO oxidation that ZnMn 1.5 TM 0.5 O 4 (TM = 3 d transition metal) with first and second NO adsorption energies (E ad) in the ranges of −2.40 ∼ −2.00 eV and −1.50 ∼ −0.25 eV respectively have good NO oxidation performance, respectively. Our paper paves a feasible road for the applications of ZnMn 1.5 TM 0.5 O 4 as the NO oxidation catalyst. [ABSTRACT FROM AUTHOR]

Special wettability such as superhydrophobicity and superhydrophilicity has aroused considerable attention in recent years, especially for the surface that can be switched between superhydrophobicity and superhydrophilicity. In this work, hierarchical bismuth nanostructures with hyperbranched dendritic architectures were synthesized via the galvanic replacement reaction between zinc plate and BiCl 3 in ethylene glycol solution, which was composed of a trunk, branches (secondary branch), and leaves (tertiary branch). After being modified by stearic acid, the as-prepared bismuth coating shows superhydrophobicity with a high water contact angle of 164.8° and a low sliding angle of 3°. More importantly, a remarkable surface wettability transition between superhydrophobicity and superhydrophilicity could be easily realized by the alternation of UV–vis irradiation and modification with stearic acid. The tunable wetting behavior of bismuth coating could be used as smart materials to make a great application in practice. [ABSTRACT FROM AUTHOR]

[Display omitted] • An L-SAH surface was fabricated for the high-throughput supraparticle synthesis. • The unique wetting state of droplets on the L-SAH surface was revealed. • The prevention of supraparticle adhesion and droplet slide was perfectly attained. • Various supraparticles with high replicability were acquired via the L-SAH surface. • The catalytic activity of photocatalytic supraparticles was proven. Self-assembly of supraparticles consisting of diverse nanoparticles by evaporating the suspension droplets on a surface have high potential in many applications. However, simultaneously preventing adhesion-induced damage during removal of the supraparticles from the surface and the high-throughput synthesis of supraparticles is challenging. Herein, to break through the bottleneck, we proposed an ingenious method that employs a biomimetic lubricated-superamphiphobic patterned surface (L-SAH surface) inspired by the synergism of a 'nepenthes cage', 'springtail skin', and 'Namib beetle skin'. On the L-SAH surface, discrete lubricant-infused areas were integrated on a superamphiphobic background. The lubricant-controlled contact angle hysteresis trap (L-CAHT) not only precisely anchored the droplets to eliminate the barely-controllable droplet slide, but also distinctly decreased the adhesion of the droplet or inner material to the solid surface because of lubricant separation. Moreover, heterogeneous supraparticles with high replicability and flexibility were acquired via the L-SAH surface. As a proof of concept, the magnet-controlled maneuverability of magnetic supraparticles and the catalytic activity of photocatalytic supraparticles were proven. With the surprising merits of flexibility, simplicity, and high precision, our promising work would open a new and significant avenue for synthesizing functional supraparticles used in environics, chromatography, catalysis, pharmacy, and energy science. [ABSTRACT FROM AUTHOR]

Highlights: [•] Sb2S3 micro-/nanorods were prepared by facile and rapid microwave irradiation method. [•] Sb2S3 films were prepared by spin-coating with different sized Sb2S3 micro-/nanorods. [•] Sb2S3 films showed size-dependent surface wettability and roughness. [•] Sb2S3 nanorods film exhibited superhydrophobic and high water adhesive property. [•] Stearic acid modified Sb2S3 nanorods film displayed excellent self-cleaning property. [Copyright &y& Elsevier]

Abstract: The (103)-oriented aluminum nitride (AlN) thin film is an attractive piezoelectric material for the applications in surface acoustic wave and film bulk acoustic wave resonator devices. In this work, we repot structural and mechanical characteristics of (103) AlN thin films deposited onto (100) Si substrates with radio frequency magnetron sputtering at different sputtering powers at 150, 250, and 350W. Comparisons were made on their crystalline structures with X-ray diffraction, surface morphologies with atomic force microscopy, mechanical properties with nanoindentation, and tribological responses with nanoscratch. Results indicate that for the sputtering power of 350W, a high-quality (103) AlN thin film, whose hardness is 18.91±1.03GPa and Young''s modulus is 242.26±8.92GPa, was obtained with the most compact surface condition. [Copyright &y& Elsevier]

Abstract: An efficient method to functionalize single-walled carbon nanotubes (SWNTs) with alcohols under microwave irradiation was reported. An electrophilic addition reaction took place between a series of alcohols and SWNTs, resulting in the attachment of various alkyl or alcoholic groups, as well as hydroxyl groups, to the surface of the nanotubes. The modified SWNTs show better dispersibility in common organic solvents (such as N, N-dimethylformamide and ethanol) than the pristine nanotubes, which is important to improve their processability. These results illustrate a direct pathway to abundantly functionalize SWNTs for building nanostructures. [Copyright &y& Elsevier]

Abstract: The thermal stability of silver films in air has been studied. Pure Ag films, 250nm in thickness, were prepared on glass substrates by thermal evaporation process, and subsequently annealed in air for 1h at temperatures between 200 and 400°C. The structure and morphology of the samples were investigated by X-ray diffraction, Raman spectra and atomic force microscopy. It is found that the crystallization enhances for the annealed films, and film surface becomes oxidized when annealing temperature is higher than 350°C. The electrical and optical properties of the films were studied by van der Pauw method and spectrophotometer, respectively. Reflectance drops sharply as Ag films are annealed at temperatures above 250°C. Film annealed at 250°C has the maximum surface roughness and the minimum reflectance at 600nm optical wavelength. Film annealed at 200°C has the minimum resistivity, and resistivity increases with the increasing of the annealing temperature when temperature is above 200°C. The results show that both oxidization on film surface and agglomeration of silver film result in infinite of electrical resistivity as the annealing temperature is above 350°C. [Copyright &y& Elsevier]

• -SH and -COOH are prone to dissociate on ZnS (10 1 ¯ 0) with binding strength order of -SH > -COOH > -NH 2. • Branched ligands bind stronger than linear ones, while chain length has less effect on the binding energy. • These ligands can passivate the surface states, however they fail to eliminate trap states of vacancies. Ligand design is an important aspect of the surface engineering on the quantum dots. Organic ligands with three types of widely used function groups (-SH, -NH 2 , -COOH) are chosen to investigate the bonding behavior and electronic properties modification on ZnS (10 1 ¯ 0) based on first-principles calculations. The thermodynamic studies of (10 1 ¯ 0) ligands suggest that -SH and -COOH are prone to undergo a proton dissociation when binding on the surface, while -NH 2 remains molecular adsorption on the 2-coordinated Zn atom. The binding strengths of these ligands exhibits the order of -SH > -COOH > -NH 2 , which is consistent with their ligand exchange ability in experiments. The gap states of ZnS (10 1 ¯ 0) mainly come from 2-coordinated S/Zn, and the passivation effect of -NH 2 ligand is inferior to the other two due to the absence of dissociated H which covers the 2-coordinated S. The change of ligand structures shows that ligand length has slight influence on the binding energies, while branched ligands bind more strongly on the surface than those linear ones with the same number of carbon atoms. As for the surface vacancies that cause severe trap states, the ligands tend to be located at bridge sites between two 2-coordinated Zn rather than filling the vacancies. Our study provides an insight into the bonding behavior and passivation mechanism of typical ligands on II-VI QDs at the atomic level and gives helpful guidance for surface engineering aimed at improving QD performance. [ABSTRACT FROM AUTHOR]

• HiPIMS was used to produce NiO film with enhanced p-type optoelectronic performance. • The high ionization rate of HiPIMS holds promise to elevate Ni3+ content. • The optimal conductivity of 50 S·cm−1 with a high hole concentration is realized. High power impulse magnetron sputtering (HiPIMS) technology has attracted lots of attention due to its high target ionization rate. This characteristic is desirable in preparing metal compounds with complex valence states. In the current work, NiO films were deposited by HiPIMS and direct current magnetron sputtering (DCMS) at various oxygen flow ratios. The films' structural and optoelectronic properties were investigated. The results show that, thanks to the enhanced Ni3+ ion density formed during the HiPIMS deposition process, more nickel vacancies are formed in the film leading to the film's carrier concentration improving significantly. NiO films deposited by HiPIMS possess much better p-type conductivity than the films deposited by DCMS. Additionally, with oxygen flow ratio increase, more interstitial oxygen can be introduced, which can also enhance the film's p-type electrical conductivity. However, these defects reduce the film's transmittance. [ABSTRACT FROM AUTHOR]