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A copper/polydimethylsiloxane (Cu/PDMS) microfluidic chip was designed to synthesize SERS substrates through a displacement reaction between silver and copper in microfluidic channels to form a microfluidic SERS nanoparticles (AgNPs)/Cu chip. This SERS substrate fabrication method doesn't require complex manufacturing processes or expensive equipment, and it can be achieved at room temperature in just 4 min. Meanwhile, the AgNPs grown on copper foil could offer ample hot spots, effectively boosting Raman signals of target molecules, and the enhancement factor (EF) was 5.12 × 107 for methylene blue, 4.08 × 107 for crystal violet, and 4.81 × 105 for sulfadiazine. The chip could be reused at least 9 times with consistent signal performance. Combined with the concentration gradient microchannel network design, we could establish the standard curve for samples through one injection on a single chip. A rapid SERS method for detecting sulfadiazine in aquatic products was developed. The linear range for sulfadiazine analysis was 75.0–1000 μg L−1 with a limit of detection of 28.4 μg L−1. Sulfadiazine was found in aquatic products (43.8 μg kg−1), with recovery rates ranging from 82.7% to 110%. The result was validated using high-performance liquid chromatography, showing a relative error of 9.3%. The entire detection procedure could be completed in just 20 min to detect sulfadiazine. These results demonstrate that the developed SERS method is fast, accurate, and reliable for analysis of sulfadiazine in aquatic products. [ABSTRACT FROM AUTHOR]

Iron-modified Ni(OH)2/NiSe2 enhances oxygen vacancies, expanding the electrochemically active surface area, which exhibiting superior selectivity and stability in urea oxidation reaction, outperforming pristine Ni(OH)2@NiSe2. It also demonstrates superior catalytic performance in the oxidation reactions of other small molecules. [ABSTRACT FROM AUTHOR]

Hydrogel-based conductive materials for smart wearable devices have attracted increasing attention due to their excellent flexibility, versatility, and outstanding biocompatibility. This review presents the recent advances in multifunctional conductive hydrogels for electronic devices. First, conductive hydrogels with different components are discussed, including pure single network hydrogels based on conductive polymers, single network hydrogels with additional conductive additives (i.e., nanoparticles, nanowires, and nanosheets), double network hydrogels based on conductive polymers, and double network hydrogels with additional conductive additives. Second, conductive hydrogels with a variety of functionalities, including self-healing, super toughness, self-growing, adhesive, anti-swelling, antibacterial, structural color, hydrophobic, anti-freezing, shape memory and external stimulus responsiveness are introduced in detail. Third, the applications of hydrogels in flexible devices are illustrated (i.e., strain sensors, supercapacitors, touch panels, triboelectric nanogenerator, bioelectronic devices, and robot). Next, the current challenges facing hydrogels are summarized. Finally, an imaginative but reasonable outlook is given, which aims to drive further development in the future. [ABSTRACT FROM AUTHOR]

Medical research reveals that keeping the skin surface dry can effectively prevent a variety of fungal skin diseases. Therefore, it is of great practical significance to develop a light, thin, comfortable and breathable functional garment fabric with efficient one-way water transmission for people's requirements. Here, we successfully prepared a three-layer stacking sandwich coating to construct a Janus nonwoven material with efficient unidirectional water transport function, viz. PDMS-ormosil-PDMS@nonwoven fabric (PDMS-ormosil-PDMS@NF). Theoretical analysis showed that the loading of ormosil particles could enhance the surface roughness, while PDMS could strengthen the hydrophobic properties and bondability between the ormosil particles and fabric, thus acting as an environmentally friendly fluorine-free treating agent. The results revealed that the hydrophilic–hydrophobic PDMS-ormosil-PDMS@nonwoven fabric maintained excellent hydrophobic stability and good air permeability even after abrasion, which solved the existing problems of aerogel poor deposition and PDMS poor permeability, benefiting the application of textiles with unidirectional water transport performance. [ABSTRACT FROM AUTHOR]

Condensation of an (S)- or (R)-BINOL-derived dialdehyde and tris(2-aminoethyl)amine produced chiral [2+3] imine cages, which were further reduced to furnish more stable chiral amine cages and applied in the enantioselective recognition of (1R,2R)- and (1S,2S)-1,2-diaminocyclohexane. [ABSTRACT FROM AUTHOR]

Metal–organic frameworks (MOFs) are a special class of porous materials and have been widely explored for applications in supercapacitors, catalysts, and adsorbents, because of their large specific surface areas and tunable structure and composition. However, traditional MOFs suffer from poor conductivity and low stability, which limit their efficiency in catalysis and other applications that require good electrical conduction. To overcome this limitation, a composite made of electrically conducting graphene and MOFs is conceptually a viable solution. This review summarizes the latest preparation methods for MOF/graphene materials with a focus on applications in electrocatalysis and photocatalysis. We aim to assist existing researchers to obtain a fast and holistic overview of MOF and their derivatives with graphene composites in catalysis, and also the new comers to quickly catch up with the latest development in this field. [ABSTRACT FROM AUTHOR]

The design of advanced supercapacitors requires electrode materials that combine high surface area with a developed hierarchical porous structure to facilitate ion transport and electrolyte permeability. Herein, we report a cross-linking and in situ sulfuration strategy for synthesizing nickel sulfide (Ni3S2) nanocrystal-attached cobalt sulfide (Co9S8) encapsulated on three-dimensional (3D) N-doped hierarchical porous carbon (Ni3S2@Co9S8/N-HPC). The Ni3S2@Co9S8/N-HPC composite was extensively studied using different characterization technologies. The results revealed that the obtained material integrated the advantages of a developed N-doped carbon framework (fast ion transport and excellent electrical conductivity) and transition metal sulfide species (high theoretical specific capacitance). Benefiting from the synergistic effect of a strawberry-like Ni3S2@Co9S8 structure and 3D interconnected hierarchical porous carbon, the resulting Ni3S2@Co9S8/N-HPC composite exhibited an ultrahigh attractive specific capacitance of 1970.5 F g−1 at a current density of 0.5 A g−1 and excellent cycling stability with a capacitance retention of 89.5% after 5000 cycles at 10 A g−1. In addition, an asymmetric supercapacitor (ASC) of Ni3S2@Co9S8/N-HPC//HPC was assembled in a 6 M KOH electrolyte. It delivered an energy density of 77.1 W h kg−1 at a power density of 263.3 W kg−1, and it remained as high as 36.1 W h kg−1 even at 25.9 kW kg−1. It is believed that the presented work opens up a new strategy to fabricate high-performance supercapacitor electrodes. [ABSTRACT FROM AUTHOR]

Traditional superhydrophobic coatings prepared from non-degradable materials tend to do harm to the environment throughout the fabrication process as well as after being discarded. Great efforts have been devoted to exploring more environmentally friendly approaches and materials to settle this problem. Here we report an eco-friendly strategy based on aqueous systems to construct superhydrophobic coatings on various fabrics. Fabrics were first coated with polydopamine (PDA) and then modified with the stearic acid emulsion to introduce the desired surface morphology and energy. The as-prepared fabrics achieved robust superhydrophobicity with a contact angle (CA) about 162.0° and sliding angle (SA) about 7.8°. Moreover, due to the UV-absorbing and the photo-thermal conversion ability of PDA, the modified fabrics exhibited excellent UV shielding and solar-induced self-healing properties. The as-prepared fabrics also possessed high efficiency oil–water separation properties. Without the usage of harmful organic solvents and the addition of micro/nano-particles, this biodegradable superhydrophobic fabric exhibited a clear advantage of being environmentally friendly over conventional coatings. Furthermore, the facile and low-cost fabrication process makes its large-scale production easy. [ABSTRACT FROM AUTHOR]

Liquid mobility on super-wettable materials is of interest for enhanced heat transfer, self-cleaning, anti-fouling, anti-icing, water-harvesting, and oil–water separation. Here, we review different mechanisms related to liquid mobility on super-wettable materials, encompassing some classical wetting theories and liquid transport behaviors observed on biological surfaces with special textures. Then, the different categories of liquid behaviors on super-wettability materials are summarized, focusing on recent progress on vertical motion (droplet self-propelling and bouncing), horizontal transportation (transportation on one-dimensional (1D) and two-dimensional (2D) materials), and interfacial penetration (oil–water penetration and water penetration). Along these lines, we also review the latest applications in energy and the environment, followed by presenting the outlook and key challenges. [ABSTRACT FROM AUTHOR]

Titanium dioxide nanotubes (TNTs) have drawn wide attention and been extensively applied in the field of biomedicine, due to their large specific surface area, good corrosion resistance, excellent biocompatibility, and enhanced bioactivity. This review describes the preparation of TNTs and the surface modification that entrust the nanotubes with better antibacterial property and enhanced osteoblast adhesion, proliferation, and differentiation. Considering the contact between TNTs’ surface and surrounding tissues after implantation, the interactions between TNTs (with properties including their diameter, length, wettability, and crystalline phase) and proteins, platelets, bacteria, and cells are illustrated. The state of the art in the applications of TNTs in dentistry, orthopedic implants, and cardiovascular stents are introduced. In particular, the application of TNTs in biosensing has attracted much attention due to its ability for the rapid diagnosis of diseases. Finally, the difficulties and challenges in the practical application of TNTs are also discussed. [ABSTRACT FROM AUTHOR]

To develop an efficient visible-light-driven photocatalyst electrode for environmental remediation, a novel ternary nanocomposite of an Au-decorated Bi2MoO6 nanosheet/TiO2 nanotube array (NTA) heterojunction was successfully fabricated for the first time via a facile solvothermal method combined with mussel-inspired functional modification of electrochemical polymerization of dopamine. In this strategy, the Au3+ ions were in situ reduced to metallic Au nanoparticles (NPs) due to the abundant catechol and amine groups from the polydopamine layer. The resulting Au/Bi2MoO6@TiO2 NTAs heterostructural electrode greatly exhibits enhanced electrochemical properties and excellent photocatalytic performance for the photo-degradation of organic dyes (methylene blue) and benzene series compounds (BSCs) under UV and visible-light irradiation. The improved photocatalytic performance is mainly ascribed to the surface plasmon resonance (SPR) effect induced by Au NPs and the cooperative electronic capture properties of Au NPs, Bi2MoO6 nanosheets and TiO2 NTAs, resulting in the extended absorption in the visible-light region and effectively preventing the recombination of electron–hole pairs and transfer of the electrons which participate in the photo-degradation process. Moreover, the stability of the photocatalysts and mechanisms for the sustainable photocatalysis are discussed. [ABSTRACT FROM AUTHOR]

The development of scalable and reliable three-dimensional macroscopic functional aerogels is of remarkable significance because of their wide applications in the energy and environmental fields. Although the metal–organic frameworks (MOFs) have shown promising applications in water remediation, the construction of MOFs-based aerogels is highly challenging. Herein, for the first time, we report a general strategy for one-step fabrication of a ZIF-8 MOF/reduced graphene-oxide hydrogel in a short period via self-assembly, with the synergistic effects of chemical reduction and cross-linking by metal ions; upon drying, the hydrogel yields the ZIF-8/reduced graphene-oxide aerogel. The highly porous ZIF-8 hybrid aerogel displays high absorption capacity and cycling stability for oils and organic solvents, due to its superhydrophobic properties and high specific surface areas. In addition, the corresponding hydrogel demonstrates photocatalytic dye degradation ability, as well as excellent water purification performance for removing toxic dyes, heavy metal ions and benzo pollutants. Our synthetic strategy is proven to be versatile for constructing a variety of functional nanocomposite hydro-/aerogels towards customized water remediation. [ABSTRACT FROM AUTHOR]

Inspired by the superhydrophobic lotus surface in nature, special wettability has attracted a lot of interest and attention in both academia and industry. In this review, theoretical models and fabrication strategies of superhydrophobic textiles have been discussed in detail. The strategies for constructing fabric surfaces with an anti-wetting property are categorized and discussed based on the morphology of particles coated on the textile fibre. Such special wettability textile surfaces are demonstrated with self-cleaning, oil/water separation, self-healing, UV-blocking, photocatalytic, anti-bacterial, and flame-retardant performances. Correspondingly, potential applications have been illustrated for self-cleaning, oil/water separation, asymmetric/anisotropic wetting janus fabric, microfluidic manipulation, and micro-templates for patterning. In each section, representative studies are highlighted with emphasis on the special wetting ability and other relevant properties. Finally, the difficulties and challenges for practical application were briefly discussed. [ABSTRACT FROM AUTHOR]

Superhydrophobic cotton fabrics were prepared via a facile and environmentally friendly strategy to deposit an organically modified silica aerogel (ormosil) thin film onto the fabrics first, followed by polydimethylsiloxane (PDMS) topcoating. The PDMS–ormosil coating displayed a uniform 3D fractal-like structure with numerous loose micro-scale pores, while the PDMS layer increased the binding strength of the hierarchical ormosil film to form a highly robust porous network on the fibers. In comparison with hydrophilic cotton fabrics, the modified cotton fabric exhibited a highly superhydrophobic activity with a water contact angle higher than 160° and a sliding angle lower than 10°. The as-constructed PDMS–ormosil@fabrics are able to withstand 100 cycles of abrasion and 5 cycles of accelerated machine wash without an apparent decrease of superhydrophobicity. In addition, the superhydrophobic cotton fabrics are very stable in strongly acidic and alkaline solutions. Furthermore, the superhydrophobic coating has no or negligible adverse effect on the important textile physical properties of the cotton fabric, such as the strength, air permeability, and flexibility. The composite super-antiwetting fabrics have demonstrated excellent anti-fouling, self-cleaning ability and are highly efficient in oil–water separation for various oil–water mixtures. This facile synthesis technique has the advantages of scalable fabrication of multifunctional fabrics for potential applications in self-cleaning and versatile water–oil separation. [ABSTRACT FROM AUTHOR]

One-dimensional TiO2 (1D TiO2) nanomaterials with unique structural and functional properties have been extensively used in various fields including photocatalytic degradation of pollutants, photocatalytic CO2 reduction into energy fuels, water splitting, solar cells, supercapacitors and lithium-ion batteries. In the past few decades, 1D TiO2 nanostructured materials with a well-controlled size and morphology have been designed and synthesized. Compared to 0D and 2D nanostructures, more attention has been paid to 1D TiO2 nanostructures due to their high aspect ratio, large specific surface area, and excellent electronic or ionic charge transport properties. In this review, we present the crystal structure of TiO2 and the latest development on the fabrication of 1D TiO2 nanostructured materials. Besides, we will look into some critical engineering strategies that give rise to the excellent properties of 1D TiO2 nanostructures such as improved enlargement of the surface area, light absorption and efficient separation of electrons/holes that benefit their potential applications. Moreover, their corresponding environmental and energy applications are described and discussed. With the fast development of the current economy and technology, more and more effort will be put into endowing TiO2-based materials with advanced functionalities and other promising applications. [ABSTRACT FROM AUTHOR]

A novel femtosecond laser patterning technique is reported to construct a three-dimensional (3D) wettability pattern on a superhydrophobic TiO[sub 2] nanotube array (TNA) surface in one-step. A 3D binary TNA pattern with extremely high contrast for microfluidic manipulators and biomedical scaffolds is used to guide droplet transportation and human mesenchymal stem cell site-selective growth, respectively. [ABSTRACT FROM AUTHOR]

Hierarchical surfaces with specific topographical morphology and chemical components can be found on many living creatures in nature. They offer special wettability and adhesion (sliding, sticky or patterned superhydrophobic surfaces), a functional platform for microfluidic management and other biological functions. Inspired by their precise arrangement of structures and surface components, we described a facile one-step electrochemical technique to create dual-scale hierarchical anatase TiO2 structures with the combination of pinecone-like micro-particle upper layers and dense-stacked nanoparticle bottom layers in a large scale. The as-prepared TiO2 films display environment-responsive wettability with good dynamical stability. Extremely high contrast of adhesion (2.5–170 μN) can be realized by simply adjusting the physical structures (anodizing voltage and electrolyte concentration dependent) to control the solid–liquid contact state (from “Rose” to “Lotus” state). In addition, erasable and rewritable patterned superhydrophobic TiO2 films were constructed for a versatile platform for microfluidic management. In a proof-of-concept study, robust super-antiwetting films for on-demand droplet separation, mixing and transportation under an ambient atmosphere or an underwater environment, and patterned superhydrophobic surfaces for liquid self-assembling or anti-counterfeiting marks were demonstrated. [ABSTRACT FROM AUTHOR]

Exploring eco-friendly and cost-effective strategies for structure engineering at the nanoscale is important for boosting heterogeneous catalysis but still under a long-standing challenge. Herein, multifunctional polyphenol tannic acid, a low-cost natural biomass containing catechol and galloyl species, was employed as a green reducing agent, chelating agent, and stabilizer to prepare Au nanoparticles, which were dispersed on different-shaped CeO 2 supports ( e.g. , rod, flower, cube, and octahedral). Systematic characterizations revealed that Au/CeO 2 -rod had the highest oxygen vacancy density and Ce(III) proportion, favoring the dispersion and stabilization of the metal active sites. Using isopropanol as a hydrogen-transfer reagent, deep insights into the structure-activity relationship of the Au/CeO 2 catalysts with various morphologies of CeO 2 in the catalytic nitrobenzene transfer hydrogenation reaction were gained. Notably, the catalytic performance followed the order: Au/CeO 2 -rod (110), (100), (111) > Au/CeO 2 -flower (100), (111) > Au/CeO 2 -cube (100) > Au/CeO 2 -octa (111). Au/CeO 2 -rod displayed the highest conversion of 100% nitrobenzene and excellent stability under optimal conditions. Moreover, DFT calculations indicated that nitrobenzene molecules had a suitable adsorption energy and better isopropanol dehydrogenation capacity on the Au/CeO 2 (110) surface. A reaction pathway and the synergistic catalytic mechanism for catalytic nitrobenzene transfer hydrogenation are proposed based on the results. This work demonstrates that CeO 2 structure engineering is an efficient strategy for fabricating advanced and environmentally benign materials for nitrobenzene hydrogenation.

In this work, the treatment of textile wastewater by a facile and high-efficiency technology using eco-friendly Aspergillus niger as a biosorbent was investigated. We measured physical changes (weight, size) during the formation and growth of fungus pellets and the pH values that influence the adsorption performance and biosorption mechanism. Three acid anionic dyes containing Acid Orange 56, Acid Blue 40 and Methyl Blue were chosen as model dyes to investigate batch adsorption efficiency. Two adsorption models ( in vivo and in vitro ) were adopted to decolorize the acid dyes. The results show that fungus pellets have excellent decoloration abilities with a high adsorption efficiency of 98% for 200 mg L -1 of acid dye. The pH value of the dye solution varied with the adsorption time and the dye removal efficiency greatly depended on the pH. The bioadsorption mechanism of nano-scale hyphae was revealed to be mainly due to electrostatic interactions caused by the pH change. Furthermore, the surface morphologies of the fungus after adsorption indicated that the dyes had been adsorbed on the surface of the fungus mycelia. Moreover, prepared 3D fungus/GO aerogels demonstrated superior dye removal abilities compared with fungus aerogels., Competing Interests: The authors declare that they have no conflicts of interest., (This journal is © The Royal Society of Chemistry.)

Oil-water separation is critical for the water treatment of oily wastewater or oil-spill accidents. The oil contamination in water not only induces severe water pollution but also threatens human beings' health and all living species in the ecological system. To address this challenge, different nanoscale fabrication methods have been applied for endowing biomimetic porous materials, which provide a promising solution for oily-water remediation. In this review, we present the state-of-the-art developments in the rational design of materials interface with special wettability for the intelligent separation of immiscible/emulsified oil-water mixtures. A mechanistic understanding of oil-water separation is firstly described, followed by a summary of separation solutions for traditional oil-water mixtures and special oil-water emulsions enabled by self-amplified wettability due to nanostructures. Guided by the basic theory, the rational design of interfaces of various porous materials at nanoscale with special wettability towards superhydrophobicity-superoleophilicity, superhydrophilicity-superoleophobicity, and superhydrophilicity-underwater superoleophobicity is discussed in detail. Although the above nanoscale fabrication strategies are able to address most of the current challenges, intelligent superwetting materials developed to meet special oil-water separation demands and to further promote the separation efficiency are also reviewed for various special application demands. Finally, challenges and future perspectives in the development of more efficient oil-water separation materials and devices by nanoscale control are provided. It is expected that the biomimetic porous materials with nanoscale interface engineering will overcome the current challenges of oil-water emulsion separation, realizing their practical applications in the near future with continuous efforts in this field.

Titanium dioxide nanotubes (TNTs) have drawn wide attention and been extensively applied in the field of biomedicine, due to their large specific surface area, good corrosion resistance, excellent biocompatibility, and enhanced bioactivity. This review describes the preparation of TNTs and the surface modification that entrust the nanotubes with better antibacterial property and enhanced osteoblast adhesion, proliferation, and differentiation. Considering the contact between TNTs' surface and surrounding tissues after implantation, the interactions between TNTs (with properties including their diameter, length, wettability, and crystalline phase) and proteins, platelets, bacteria, and cells are illustrated. The state of the art in the applications of TNTs in dentistry, orthopedic implants, and cardiovascular stents are introduced. In particular, the application of TNTs in biosensing has attracted much attention due to its ability for the rapid diagnosis of diseases. Finally, the difficulties and challenges in the practical application of TNTs are also discussed.

A novel femtosecond laser patterning technique is reported to construct a three-dimensional (3D) wettability pattern on a superhydrophobic TiO 2 nanotube array (TNA) surface in one-step. A 3D binary TNA pattern with extremely high contrast for microfluidic manipulators and biomedical scaffolds is used to guide droplet transportation and human mesenchymal stem cell site-selective growth, respectively.