•Polyacrylonitrile paper was functionalized with polydopamine and Ag nanoparticles.•Polydopamine coating layer played both reductive and adhesive roles.•The composite material displayed good catalytic activity for 4-nitrophenol reduction.•The process was environmentally benign and facile.The study reports on the preparation of polyacrylonitrile fiber paper (PANFP) functionalized with polydopamine (PD) and silver nanoparticles (Ag NPs), named as Ag NPs/PD/PANFP. The composite material was obtained via a simple two-step chemical process. First, a thin polydopamine layer was coated onto the PANFP surface through immersion into an alkaline dopamine (pH 8.5) aqueous solution at room temperature. The reductive properties of polydopamine were further exploited for the deposition of Ag NPs. The morphology and chemical composition of the composite material were characterized using scanning electron microscopy (SEM), X-ray diffraction pattern (XRD) and X-ray photoelectron spectroscopy (XPS). The catalytic activity of the nanocomposite was evaluated for the reduction of 4-nitrophenol using sodium borohydride (NaBH4) at room temperature. The Ag NPs/PD/PANFP displayed good catalytic performance with a full reduction of 4-nitrophenol into the corresponding 4-aminophenol within 30 min. Moreover, the composite material exhibited a good stability up to 4 cycles without a significant loss of its catalytic activity.Illustration of the preparation of Ag nanoparticles coated paper and its catalytic application for 4-nitrophenol reduction into the corresponding 4-aminophenol.Download high-res image (89KB)Download full-size image

•Superhydrophobic Au surface was fabricated on iron substrate.•The growth process of the surface didn't use any organic modification.•Corrosion resistance, self-cleaning and mechanical durability were studied.Well-defined gold nanoflower superhydrophobic surface (SHS) was constructed on iron foil by chemical deposition and anneal. The as-fabricated sample exerts excellent superhydrophobicity with water contact angle (WCA) up to 169°, a sliding angle of about 3°. The samples were characterized via scanning electron microscopy (SEM), X-ray diffraction pattern (XRD) and energy dispersive analysis of X-ray (EDX) to determine the morphology, structure and composition. The electrochemical measurements showed that the resultant surface displayed good corrosion resistance in 3.5 wt% sodium chloride aqueous solution. The effect of pH on the SHS and corrosion resistance ability of the samples at pH = 2, 7 and 9 were explored. The self-cleaning property of the SHS was analyzed. Also, the surface withstood abrasion by 400 grid SiC sandpaper for 2.0 m under 30 kPa, or water impacting for 120 min without losing its superhydrophobicity, indicating prominent mechanical durability. This successful manufacture of the gold SHS with anti-corrosion, self-cleaning, and mechanical durability can pave a prospective way for a variety of practical situations.Download high-res image (124KB)Download full-size image

•The method did not need to introduce any organic reagent as the modifier.•Contact angle of 169° and a sliding angle of less than 1°.•The superhydrophobic surface exhibited good catalytic activity.•The super buoyancy force is 6.14 times of the ordinary buoyancy.A textured ice edge-like Ir-ZnO/Zn superhydrophobic surface (SHS) with a water contact angle of 169° and a sliding angle of less than 1° was fabricated on zinc substrates via immersing the processed zinc sheet perpendicularly into iridium (III) chloride aqueous solution and annealing treatment. The morphology and chemical composition of the resulted SHS were characterized using scanning electron microscopy (SEM), X-ray diffraction pattern (XRD) and X-ray photoelectron spectrometry (XPS). The Ir-ZnO/Zn SHS exhibited properties of lasting stability, excellent self-cleaning ability, superior corrosion resistance, super buoyancy force as well as catalyzer. The super buoyancy force of the resulted sample is 6.14 times that of zinc sheet. The Ir-ZnO/Zn SHS exhibited good catalytic activity with a full degradation of methyl orange within 80 min under an ultraviolet (UV) lamp with a light intensity of 8 W. Moreover, the Ir-ZnO/Zn SHS exhibited a good stability up to 3 recycles without a significant loss of its catalytic activity.Download high-res image (185KB)Download full-size image

•A composite Co-Al alloy superhydrophobic surface was prepared.•The as-prepared surfaces exhibited excellent superhydrophobicity.•The superhydrophobic surface exhibited good corrosion resistance.•The superhydrophobic surface exhibited good catalytic activity.A textured flower-like cobalt superhydrophobic surface (SHS) with a water contact angle of 160° and a sliding angle of less than 1° was fabricated on aluminum substrate by immersing the processed aluminum sheets perpendicularly into cobalt (II) nitrate aqueous solution and followed by annealing treatment. The morphology and chemical composition of the SHS were characterized using scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray diffraction pattern (XRD), Energy-dispersive spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS). The corrosion resistance of the samples was characterized via polarization, Nyquist and bode modulus plots. The photocatalysis of samples was also studied by catalytic degradation of methyl orange under a UV lamp (λ = 365 nm) with a light intensity of 8 W. The cobalt superhydrophobic sample not only exhibited excellent catalytic properties, but also substantially improved the corrosion resistance of aluminum substrate.Download high-res image (84KB)Download full-size image

Herein, Cu–CuO–Fe2O3/Fe superhydrophobic surfaces (SHSs) were successfully fabricated on an iron substrate via chemical substitution deposition and subsequent annealing treatment. The resulting surfaces exhibit remarkable superhydrophobicity with a water CA of 165 ± 2° and an SA of approximately 0° without any organic modification. The surface morphology and chemical compositions were investigated using field emission scanning electron microscopy (FESEM), energy dispersive spectroscopy (EDS), X-ray powder diffraction (XRD), and X-ray photoelectron spectroscopy (XPS); moreover, the surface roughness was analyzed via atomic force microscopy (AFM). The thermal treatment, which caused generation of a new chemical substance and formation of micro-/nano-binary architectures, was important for superhydrophobicity and also enhanced the affinity of the iron substrate for the coatings. The annealing temperature and time were further investigated to explain the significance of the surface morphology and chemical composition in the fabrication of the optimal SH samples under appropriate conditions. The resulting SHSs exhibit roll-down, anti-abrasion, and anti-corrosion properties, which may have significant potential value for more applications.

•NiO/ZnO SHS have been fabricated on zinc substrate via deposition and anneal.•Anneal treatment is important for the combination between substrate and coatings.•Surface wettability is controlled and influenced by various conditions.•SHS exhibit exquisite roll-down, anti-corrosion and anti-abrasion properties.The paper reports on the preparation of NiO/ZnO superhydrophobic surfaces (SHS) on zinc via chemical substitution/deposition and thermal annealing. The resulting surfaces display superhydrophobic behavior with a water contact angle (WCA) of 153° and a sliding angle (SA) of ∼5° without the use of any additional organic coating. Using the Cassie-Baxter equation, it is found that about 91.6% serves as the contact area of the water droplet and air, leading to the roll down property of the water droplet on the surface. The surface superhydrophobicity is controlled and influenced by various preparation conditions: the thermal treatment, which causes the generation of NiO and ZnO layers, and the formation of polygonal honeycomb structures and disappearance of silk flower-like clusters. The resulting NiO/ZnO SHS exhibit roll down, anti-corrosion and anti-abrasion properties. The corrosion current density of the NiO/ZnO SHS (5.7 × 10−4 A cm−2) is decreased by more than 1 order of magnitude when compared to the untreated Zn surface (1.4 × 10−3 A cm−2). EIS results also indicate that the SHS possesses higher anti-corrosion performance. The superhydrophobic sample, after annealing treatment, can sustain a collapsing force of about 7.8 N, which is better than the superhydrophilic sample without annealing treatment (∼5.2 N). This controlled fabrication process may offer new avenues for designing superhydrophobic surfaces with corrosion resistance for more practical applications.Download high-res image (266KB)Download full-size image

•Superhydrophobic Pt3Fe/Fe composed was fabricated on iron sheet.•The growth process is without using any seed and organic solvent.•Superhydrophobic Pt3Fe/Fe composed show superior oil/water separation capacity.•Superhydrophobic Pt3Fe/Fe composed show high photocatalytic activity.Well-defined Pt3Fe/Fe superhydrophobic materials on iron sheet with special properties, such as corrosion resistance, superhydrophobicity and superoleophilicity, was fabricated. The fabrication process involved etching in hydrochloric acid aqueous solution and simple replacement deposition process without using any seed and organic solvent, and then annealing. The electrochemical measurements show that the resultant surface in 3.5% sodium chloride solution displays good corrosion resistance. Also, it is proved that the obtained surface has better mechanical abrasion resistance via scratch test. The superoleophilicity and low water adhesion force of the obtained surface endow it high oil/water separation capacity. The as-prepared nanocomposites display enhanced catalytic activity and kinetics toward degradation of methyl orange. In particular, it possesses the most efficient degradation capacity (95%) towards methyl orange at a high concentration (17.5 mg/L) in 80 min. The improved stability and excellent catalytic activity of the Pt3Fe/Fe nanocomposites promise new opportunities for the development of waste water treatment.The illustration of application of superhydrophobic Pt3Fe/Fe surfaceDownload high-res image (160KB)Download full-size image

A durable superhydrophobic tin surface with a water contact angle of 170° and a sliding angle of < 1° was fabricated on copper substrate via electrodeposition under magnetic stirring and followed by annealing treatment at 180 °C for 60 min. The resulting superhydrophobic tin surfaces shows a porous tremella-like morphology and the water drop can fully bounce as a balloon on such a surface, exhibiting excellent non-sticking property. The as-prepared superhydrophobic tin surfaces also display excellent properties of anticorrosion, self-cleaning, long-term stability and durability. The influences of magnetic stirring and electrodeposition time on the wetting properties were also investigated to understand the formation mechanism of the superhydrophobic tin surfaces. This sufficiently simple and inexpensive method may offer an effective strategy for fabricating superhydrophobic surfaces on various conductive engineering materials.

Superhydrophobic Au–Zn alloy surfaces have been fabricated successfully on a zinc substrate via chemical substitution deposition and subsequent annealing treatment. The resulting surfaces exhibited remarkable superhydrophobicity with a WCA of 170 ± 2° and a WSA smaller than 1° without any organic modification. The surface morphologies and chemical compositions were investigated using field emission scanning electron microscopy (FESEM), energy-dispersive spectroscopy (EDS), X-ray powder diffraction (XRD) and X-ray photoelectron spectroscopy (XPS), and the surface roughness was analyzed by atomic force microscopy (AFM). The theoretical mechanism for superhydrophobicity and wettability were also analyzed. The surface wettability changed from superhydrophilicity to superhydrophobicity with a stable Cassie–Baxter state via thermal treatment, which caused the generation of Au–Zn alloys (including AuZn3 and AuZn) and ZnO, and the formation of micro-/nano-binary architectures. The resulting superhydrophobic Au–Zn alloy surfaces exhibited exquisite roll-down, self-cleaning, and excellent anti-corrosion properties, and also had a firm mechanical property about 10 N, and this might have important values for more potential applications. The corrosion current density was reduced by more than 2 orders of magnitude for the resulting superhydrophobic surface in comparison with the untreated zinc surface and this should be ascribed to the contribution of Au–Zn alloys on the surface.

Superhydrophobic coatings on a copper substrate are grown via electrodeposition followed by thermal annealing. The influence of the deposition potential, zinc ion concentration, deposition time, annealing temperature and annealing time on the wetting properties was systematically investigated. The coating electrodeposited at −1.35 V for 25 min and annealed at 190 °C for 60 min exhibited excellent superhydrophobicity with a contact angle as high as 170 ± 2° and a sliding angle of almost 0°. The water drop can fully bounce as a balloon when impinging such a solid surface, exhibiting excellent non-sticking properties. By adopting various characterization methods, it was demonstrated that the as-prepared superhydrophobic surfaces also exhibited properties of anticorrosion, antiabrasion, long-term stability and durability and large buoyancy force, which offer an effective strategy and promising industrial applications for fabricating superhydrophobic surfaces on various metallic materials.

A superhydrophilic surface with a static water contact angle of 4° ± 2° via two-step immersion process and a superhydrophobic surface with a static water contact angle of 169° ± 2° and a sliding angle of almost 0° via successive thermal treatment have been successfully fabricated on aluminum substrates. Surface morphologies and chemical compositions were investigated using field emission scanning electron microscopy, X-ray powder diffraction and X-ray photoelectron spectroscopy, and the formation mechanism was also analyzed. The thermal treatment, which causes the generation of oxides and the appearance of nano-sized particles, is very important for the surface characteristic transformation from superhydrophilicity to superhydrophobicity. The effects of various experimental parameters on wettability, corrosion resistance, anti-icing and deicing properties, stability and large-area preparation were also studied. The corrosion rate of the as-prepared superhydrophobic surface decreases by about 57.6 times compared with that of the untreated aluminum surface and about 34.8 times compared with that of the pure copper surface. These excellent properties of the superhydrophobic surface may be favorable for its potential applications and industrialization.

Superhydrophobic Au–AlAu4–Al2O3 surfaces have been successfully fabricated on aluminum substrate via immersion in chloroauric acid (HAuCl4) aqueous solution and subsequent annealing treatment. The morphologies of the surfaces exhibit dendritic structures. The surface with remarkable superhydrophobic properties has a water contact angle of 171 ± 2° and a sliding angle of approximately 0°. The effects of the immersion time, immersion concentration, annealing time and annealing temperature on surface wettability were investigated in detail. The corrosion resistance of the untreated aluminum surface and the resulting Au–AlAu4–Al2O3 surface were also investigated via the Tafel extrapolation method. The corrosion current densities are reduced by more than 1 order of magnitude for the resulting surface in comparison with the untreated aluminum surface. The anticorrosion properties of the surfaces get better over the immersion time and this may be due to the generation of corrosion products, which can prevent the corrosion process and protect the substrates. Moreover, the low current density of the resulting superhydrophobic surface demonstrates its excellent corrosion resistance.

A superhydrophobic surface with a water contact angle of 159 ± 2° and a sliding angle of 2 ± 2° on a zinc substrate is reported in this article. The process is composed of etching, replacement deposition and annealing treatment. The surface morphologies, chemical compositions and hydrophobicity of the as-prepared surfaces were investigated using a scanning electron microscope, powder X-ray diffraction analysis, X-ray photoelectron spectroscopy and contact angle measurements. The superhydrophobicity of the fabricated surface results from composite structures which consist of densely packed nanoscale particles composed of tin on microscale cavities. The optimal conditions and the formation mechanism of the superhydrophobic surfaces were also studied. Moreover, the potentiodynamic polarization shows that the as-prepared superhydrophobic surface has excellent corrosion resistance, indicating promising industrial applications.

A facile, simple and novel method for controllable fabrication of a superhydrophobic surface was developed by spontaneous deposition and subsequent annealing on a copper substrate. The surface morphologies, chemical compositions and hydrophobicity of the as-prepared surfaces were investigated using field emission scanning electron microscopy, X-ray diffractometry, X-ray photoelectron spectroscopy and contact angle measurements. The superhydrophobic surface was composed of a hierarchical structure of CuO–Cu3Pt/Cu. At the optimal conditions, the surface showed good superhydrophobicity with a water contact angle of about 170 ± 2° and a sliding angle of approximately 0 ± 2°. Additionally, the formation mechanism of the superhydrophobic surface was studied. The as-prepared superhydrophobic surface exhibited good nonsticking behavior, long-term stability, and a large buoyancy force, which offers possibilities for potential applications.

•H adsorption and O vacancy on the TiO2(011) surface have been investigated.•Only the O vacancy at the side O site gives rise to a Ti-3d like band gap state.•H adsorption or O vacancy enhances the optical absorptions in the areas of infrared.The hydroxylated and reduced rutile TiO2(011)-2 × 1 surfaces have been investigated by means of first-principles density functional theory calculations. For the H adsorption and O vacancy on the rutile TiO2(011)-2 × 1 surface, we investigated three different surface O sites. Based on the adsorption and formation energy calculations, we find that the top O is an energetically preferential site for the adsorption of H atom or the formation of O vacancy. The calculated electronic structures indicate that the energetically preferential O site cannot create a band gap state; only the O vacancy at the side O site gives rise to a Ti-3d like defect level at the edge of the conduction band. It is worth mentioning that all considered configurations of the H adsorption and O vacancy on the rutile TiO2(011)-2 × 1 surface obviously enhance the optical absorptions in the areas of infrared, not just the rutile TiO2(011)-2 × 1 surface only has a good absorption edge in the visible light region.

•H3-22 is the most stable structure in all the considered Si/ZnO (0001) system.•For H3-33 and T4-33, Si3 clusters are formed. It changes to Si4 cluster for T4-44.•The absorbed Si atoms decrease the band gaps of the Si/ZnO (0001) system.•H3-11 has the most significant utilization of sunlight, and then is H3-22.Si atoms adsorbed on ZnO (0001) surface have been investigated by first principles calculations. In the considered Si/ZnO (0001) system, H3-22 is the most stable structure and then is T4-11. The adsorbed Si atoms show many interesting behaviors. For H3-22, the adsorbed Si atoms migrate from two fixed H3 sites to one T4 site and one H3 site. For T4-33 and H3-33, the adsorbed three Si atoms form triangles. For T4-44, one more adsorbed Si atom leads the triangles to change to quadrangle. The triangular or quadrilateral Si structures just belong to S3 and S4 clusters. The electronic properties indicate that the absorbed Si atoms decrease the band gaps of the Si/ZnO (0001) system. The width and position of the band gaps are influenced by the adsorption models. From the optical properties analysis of T4-11 and H3-11, it indicates that H3 sites play a critical role in the red shift of absorption edge and T4 sites almost have little contribution. For H3-33, H3-44 and T4-44, the result indicates that the formed Si clusters lead to a slightly blue shift phenomenon and prevent the absorption of sunlight in the lower energy range.

•A theoretical simulation for the surface reconstruction was carried out.•The calculated band gap of 2.08 eV reproduces the experimental value ~ 2.10 eV.•The calculated optical absorption edge shifts to the visible light range.This work investigates surface reconstruction, electronic structure, and optical properties of the rutile TiO2(011)-2 × 1 surface using means of density functional theory calculations. For the surface reconstruction of the rutile TiO2(011) surface, a theoretical simulation with forming from bulk truncation to the 2 × 1 reconstruction was carried out. The calculated band structure shows a direct band gap at Г point, and the band gap of 2.08 eV reproduces the experimental measurement value ~ 2.10 eV very well. Analysis of the density of states reveals that no surface state was introduced into the forbidden gap. Not coincidentally, the calculated optical absorption edge at about 2.01 eV further clarifies the band gap narrowing and such an intrinsic band gap nature effectively pushes the optical absorption edge into the visible light. Hence, our theoretical calculations provide evidence that the rutile TiO2(011)-2 × 1 surface possesses high photocatalytic activity.

Electronic structure, optical properties and photocatalytic activity of S-doped ZnO are investigated by density functional theory (DFT). The configurations with the substitution of O by one and two S atoms in different positions (SO, far-2SO and near-2SO) are considered, and zinc and oxygen vacancies introduced by SO doping (SO–VZn and SO–VO) are also considered. For SO-doped ZnO, S3p states locate above the top of the valence band and mix with O2p states, leading to band gap narrowing, but the influence is slight with the increase of doping concentration. The imaginary parts of dielectric functions and absorption coefficients display that S atoms doping is not the critical factor for improving the photocatalytic activity. The absorption coefficient of introduced native defect (VO and VZn) shows different features in low energy range. The existence of VO in SO-doped ZnO leads to a strong absorption in UV-light range and VZn plays a critical role in visible-light absorption, which may improve the photocatalytic activity of ZnO in the UV-visible light range, corporately.Graphical abstractThe first absorption peak of SO–VZn doped ZnO is located at 2.73 eV, indicating the VZn enhances the utilization rate of sunlight. The existence of VO leads to a strong absorption in UV-light range. Zn and O vacancy introduced by S dopants play a critical role in the photocatalytic application of ZnO..Highlights► S3p states localizing above the top of the valence band lead to band gap narrowing. ► S3p states hybridization with O2p states also lead to band gap narrowing. ► S dopants have a little contribution to photocatalytic activity. ► Defects (VO and VZn) realize photocatalytic application in UV-visible light range.

Superhydrophobic surfaces were prepared via immersing the clean perpendicular zinc substrates into aqueous copper chloride (CuCl2) solution and followed by annealing in dry air. Two Superhydrophobic models were obtained by controlling the concentration of CuCl2 aqueous solution. One had a high water contact angle (CA) of 162 ± 2° with a small sliding angle SA of less than 2 ± 1°, which was identified with Cassie–Baxter model, the other had a high CA of larger than 150° with a high adhesion, which was identified with Gecko model. CuZn5–ZnO–CuO micro–nano binary structure leads to superhydrophobicity of the surface. Wettability and durability of surfaces were investigated and a theoretical explanation on superhydrophobic surfaces is presented. Durability test was carried out to study properties of the surface. Formation mechanism of the surface was also explained.Graphical abstractThe zinc substrate was modified by chemical displacement at a perpendicular position and annealed to form the micro–nano binary structure with CuZn5–ZnO–CuO/zinc of Cassie–Baxter model and Gecko model, controlled by CuCl2 aqueous solution concentrations.Highlights► Micro–nano binary structure of Cassie–Baxter model and Gecko model are obtained. ► CuZn5–ZnO–CuO/zinc micro–nano binary structure leads to superhydrophobicity. ► The annealing plays an important role in superhydrophobicity of metallic materials. ► The superhydrophobic surface with Cassie–Baxter model shows a good durability.

Superhydrophobic surface was prepared via immersing the clean perpendicular zinc substrate into aqueous copper (II) chloride (CuCl2) solution and followed by anneal under the humid condition. The prepared samples were characterized by powder X-ray diffraction analysis, X-ray photoelectron spectroscopy, energy-dispersive X-ray spectroscopy (XPS), and scanning electron microscopy (SEM), and energy-dispersive X-ray spectrometry analysis (EDX). SEM images of the films showed that the resulted surfaces exhibit micro–nano binary structures. The resulting surfaces had a high water contact angle (CA) of larger than 150° as well as a small sliding angle (SA) of less than 6°. Cu–Zn alloy formed by chemical displacement. Crystal CuZn5 formed via crystal transition via anneal treatment. Crystal ZnO formed in air or under the humid condition. The CuZn5–ZnO micro–nano binary structures leads to the surface superhydrophobicity.Graphical abstractThe nano-grains on the micro-pillars are formed at the most thermodynamically active sites for saturation, precipitation of the zinc atoms and the surface effect of the micro structure in the process of heat treatment. The micro sized pillars and the nano sized grain composed a micro–nano binary structure, which is analogous to that of the lotus leaf.Highlights► Cu–Zn alloy formed via chemical displacement at a perpendicular way. ► Crystal CuZn5 and ZnO formed via anneal treatment in humidity. ► Micro-pillars and nano-grain composed a micro–nano binary structure. ► Micro–nano surfaces prepared exhibited good superhydrophobicity.

Quantum-sized ZnO particles supported on sepiolite (ZnO/sepiolite) was prepared by sol–gel method using the sepiolite of acid activation as carrier, zinc acetate dihydrate (Zn(CH3COO)2·2H2O) and lithium hydroxide monohydrate (LiOH·H2O) as raw material. The size of ZnO which supported on fibrous sepiolite is about 5 nm when calcined at 200 °C. The behavior of ZnO/sepiolite composites in the degradation of C.I. Reactive Blue 4 was investigated. Under the optimal preparation conditions, when the content of ZnO was about 70 wt.% in the nanocomposites, the photocatalytic property of the ZnO/sepiolite was excellent. The degradation rate of 20 mg/L C.I. Reactive Blue 4 could get to 98% in 120 min at room temperature when the concentration of catalyst was 0.2 g/L. The photocatalytic decomposition of organic pollutants accords with a pseudo first-order kinetic. The pH and H2O2 influence the degradation rate of the ZnO/sepiolite. The experiment indicated that after the catalyst had been used 5 times repeatedly, the degradation rate had been still above 80%.Graphical abstractQuantum-sized ZnO particles supported on sepiolite was prepared by sol–gel method. The photocatalytic property of the ZnO/sepiolite composites was investigated.Research highlights► ZnO supported on sepiolite improve the photocatalytic performance. ► The size of ZnO supported on sepiolite was small. ► The ZnO/sepiolite can be used as adsorbents and photocatalysts. ► The ZnO/sepiolite system was easy to be gathered and recycled.

The precursor of Fe2O3 was prepared by chemical precipitation method with sodium hydroxide (NaOH) and iron chloride hexahydrate (FeCl3 · 6H2O). The samples annealed at different temperature were characterized by means of X-ray diffraction (XRD) and infrared absorption spectroscopy (IR). Degradation of reactive dye in aqueous solution was used to evaluate the catalytic performance of the Fe2O3. The experiments of degradation had been done in dark place. The experimental results indicated that the catalytic property of the precursor of α-Fe2O3 was excellent. The mechanism of the degradation of reactive dye in aqueous solution was investigated by comparing the data in the absence and presence of oxygen. The precursor of α-Fe2O3 annealed at 300 °C was the best. The degradation rate of reactive brilliant blue X-BR could exceed 95% in 8 min at 25 °C when the concentration of the precursor of α-Fe2O3 was 0.1 g/L. The mechanism of the catalytic oxidation reaction was investigated by comparing the X-BR catalytic oxidation data in the absence and presence of oxygen.

Superhydrophobic Au–Zn alloy surfaces have been fabricated successfully on a zinc substrate via chemical substitution deposition and subsequent annealing treatment. The resulting surfaces exhibited remarkable superhydrophobicity with a WCA of 170 ± 2° and a WSA smaller than 1° without any organic modification. The surface morphologies and chemical compositions were investigated using field emission scanning electron microscopy (FESEM), energy-dispersive spectroscopy (EDS), X-ray powder diffraction (XRD) and X-ray photoelectron spectroscopy (XPS), and the surface roughness was analyzed by atomic force microscopy (AFM). The theoretical mechanism for superhydrophobicity and wettability were also analyzed. The surface wettability changed from superhydrophilicity to superhydrophobicity with a stable Cassie–Baxter state via thermal treatment, which caused the generation of Au–Zn alloys (including AuZn3 and AuZn) and ZnO, and the formation of micro-/nano-binary architectures. The resulting superhydrophobic Au–Zn alloy surfaces exhibited exquisite roll-down, self-cleaning, and excellent anti-corrosion properties, and also had a firm mechanical property about 10 N, and this might have important values for more potential applications. The corrosion current density was reduced by more than 2 orders of magnitude for the resulting superhydrophobic surface in comparison with the untreated zinc surface and this should be ascribed to the contribution of Au–Zn alloys on the surface.

Superhydrophobic coatings on a copper substrate are grown via electrodeposition followed by thermal annealing. The influence of the deposition potential, zinc ion concentration, deposition time, annealing temperature and annealing time on the wetting properties was systematically investigated. The coating electrodeposited at −1.35 V for 25 min and annealed at 190 °C for 60 min exhibited excellent superhydrophobicity with a contact angle as high as 170 ± 2° and a sliding angle of almost 0°. The water drop can fully bounce as a balloon when impinging such a solid surface, exhibiting excellent non-sticking properties. By adopting various characterization methods, it was demonstrated that the as-prepared superhydrophobic surfaces also exhibited properties of anticorrosion, antiabrasion, long-term stability and durability and large buoyancy force, which offer an effective strategy and promising industrial applications for fabricating superhydrophobic surfaces on various metallic materials.