•State-of-the-art development on the fabrication of various TiO2 materials is reviewed.•Heterogeneous structures are designed by various strategies for enhanced H2O splitting activity.•Challenge and perspective on TiO2 materials are stated for efficient H2 production.Hydrogen is an attractive alternative to fossil fuels that addresses several environmental and energy shortage issues. Nano-sized TiO2-based photocatalysts with unique structural and functional properties are the most extensively studied photocatalytic nanomaterials for hydrogen production and pollutant degradation. However, titania is hampered by a wide band gap, low utilization of solar light and a rapid recombination of electron/hole pairs. These issues limit its photocatalytic performance. In this review, we present the latest developments in the fabrication of different higher dimensional TiO2 nanostructured materials that aim to address these inherent limitations to an otherwise very promising material. Specifically, we will look into critical engineering strategies to enlarge the active surface area, enhance visible light absorption and suppress the recombination of electrons/holes that benefit their photo/photoelectric-catalytic water splitting activity. Finally, the current challenges and perspectives for TiO2 nanostructures are also discussed. Continuous efforts are necessary to endow TiO2-based materials with novel advanced functionality and commercialization potential in the coming years.The state-of-the-art development of fabrication method on 0D, 1D, 2D and 3D TiO2 nanostructures is reviewed first. And then we will look into some critical engineering strategies to enlarge the active surface area, enhance visible light absorption and suppress the recombination of electrons/holes that benefit their photo/photoelectro-catalytic water splitting activity.Download high-res image (286KB)Download full-size image

Superhydrophobic surfaces in nature have attracted a great deal of interest not only for fundamental understanding but also for practical applications through mimicking the nature. Fluorochemicals, due to their intrinsic low surface energy, have been widely applied as artificial superhydrophobic functionalization materials with excellent performance. However, the use of these materials for practical applications might be restricted due to the relative high cost and potential hazards to human health. In this work, a low-cost and environmentally friendly short silane chain material is developed for fabricating superhydrophobic surfaces. A transparent photoactive coating is obtained by polycondensation of trichlorovinylsilane on cotton fabrics. The coating shows excellent superhydrophobicity. After being grafted with vinyl group, the coating can be easily functionalized using a photoclick thiol-ene reaction. The thiol-ene reaction has resulted in highly uniform polymer networks, which makes it possible to realize the rapid wettability switch from superhydrophobic to superhydrophilic state. Such ability makes it potentially viable to prepare well-defined cotton patterning by printing, and realize flexible electronic devices when electrodes are printed on the fabrics.

On-demand, ultrahigh precision delivery of molecules and cells assisted by scaffold is a pivotal theme in the field of controlled release, but it remains extremely challenging for ceramic-based macroporous scaffolds that are prevalently used in regenerative medicine. Sea sponges (Phylum Porifera), whose bodies possess hierarchical pores or channels and organic/inorganic composite structures, can delicately control water intake/circulation and therefore achieve high precision mass transportation of food, oxygen, and wastes. Inspired by leuconoid sponge, in this study, the authors design and fabricate a biomimetic macroporous ceramic composite sponge (CCS) for high precision logic delivery of molecules and cells regulated by mechanical stimulus. The CCS reveals unique on-demand AND logic release behaviors in response to dual-gates of moisture and pressure (or strain) and, more importantly, 1 cm3 volume of CCS achieves unprecedentedly delivery precision of ≈100 ng per cycle for hydrophobic or hydrophilic molecules and ≈1400 cells per cycle for fibroblasts, respectively.

Correction for ‘3D Au-decorated Bi2MoO6 nanosheet/TiO2 nanotube array heterostructure with enhanced UV and visible-light photocatalytic activity’ by Jingsheng Cai et al., J. Mater. Chem. A, 2017, DOI: 10.1039/c7ta02077e.

In this work, multifunctional superamphiphobic fabrics with special wettability were constructed by a facile dip-coating or electrospraying process using easily available materials, viz. silica nanoparticles, heptadecafluorononanoic, and fluoroalkyl silane. The obtained HFA–FAS–SiO2 NPs@surface exhibited a contact angle (CA) of 166.4 ± 3.7° and 155.9 ± 2.1° to water and hexadecane, respectively. In addition, this surface also showed stable repellency toward various corrosive droplets at a wide range of pH values, including HCl (pH = 1), NaCl (pH = 7), and NaOH (pH = 14) solutions. After immersion in the strong acid and base solutions for 24 h, the cotton surface still maintained excellent anti-wetting property. The surface was durable enough to withstand 120 cycles of abrasion and 5 cycles of accelerated standard laundry and still kept a water CA higher than 140° and an oil CA higher than 120°. Another treatment method adopted in this work, electrospraying has been proved to be able to realize asymmetric wetting with one side displaying highly anti-wetting behavior and the other side retaining the inherent hydrophilic and oleophilic nature of the pristine cotton fabric. Based on this special wettability, the obtained fabric could display a one-way directional transport feature. This method can also be extended to create hydrophilically and oleophilically patterned superamphiphobic cotton fabrics using a template. This novel fabric is useful for the development of intelligent cellulose-based substrates for various applications.

•Multifunctional fabrics were fabricated via dip coating of polydimethylsiloxane, ZnO, and polydimethylsiloxane layers.•Samples exhibited excellent anti-wetting properties, good abrasion resistance, and durable laundering stability.•The fabrics displayed excellent UV-shielding ability due to the incorporation of ZnO particles.•The fabrics are superhydrophobic and self-cleaning, and can be used for oil-water separation.It remains a great challenge to prepare multi-functional fabrics using a low-cost and scalable method with fluorine-free materials. In this paper, we report a new procedure for producing fluorine-free super hydrophobic cotton fabrics, via a simple dip-coating process. Firstly, a polydimethylsiloxane (PDMS) adhesive layer is deposited onto the cotton substrate, followed by the subsequent deposition of ZnO nanoparticles to enhance the surface roughness through an oil bath process. Finally, a second PDMS dip-coating is applied to construct a multi-layered PDMS-ZnO-PDMS composite coating on the cotton fabrics. The multi-layer coated samples display superhydrophobic properties, with a water contact angle (CA) exceeding 160°. Additionally, the new PDMS-ZnO-PDMS@cotton fabric exhibits excellent multi-functions, including UV-blocking, self-cleaning and oil-water separation. The prepared superhydrophobic fabric can withstand a large number of abrasion cycles and 20 cycles of accelerated washing without obvious decline in the water contact angle. This facile preparation method is of low-cost, environmentally friendly, and suitable for large-scale production of a series of specialty fabrics including sports clothing.Download high-res image (157KB)Download full-size image

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.

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.

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.

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.

•Multifunctional fabrics were constructed via a facile one-step hot-pressing process.•Superhydrophobicity was achieved by grafting environmentally-friendly fluorine-free silane.•Excellent anti-wetting property was achieved, combined with superior abrasion and laundering stability.•UV-protection and oil-water separation ability of TiO2@fabrics were demonstrated.The superhydrophobic TiO2 coating was fabricated on cotton fabric through a facile one step hot-pressing process after being dipped in n-octyltriethoxysilane and Ti-containing precursor mixed solution. The as-prepared fabric exhibited robust superhydrophobic with a water contact angle higher than 150° and realized an optimized UV protective factor of 45. The as-constructed superhydrophobic fabric was able to withstand more than 800 cycles of abrasion. Moreover, there was not apparent decrease of superhydrophobicity after 10 cycles of accelerated machine wash and the as-constructed fabric also showed a strong ability to resist acidic and alkaline solutions. Finally, the potential applications of such value-added fabrics self-cleaning, anti-fouling, and water-oil separation were investigated as well. The results demonstrated that the combination of n-octyltriethoxysilane and Ti-containing precursor coating endowed the pristine fabrics with excellent self-cleaning for dusts and anti-fouling for methylene blue dye, as well as excellent separation efficiency for the oil-water mixtures. This facile synthesis stragegy can also be extended to quickly construct multifunctional fabrics with speical wettability in a large scale and utilized in some promising fields.Download high-res image (138KB)Download full-size image

This work presents a novel approach for preparing photocatalysts based on TiO2 nanotube arrays (TiO2 NTAs) anchored with carbon dots (CDs) by a facile two-step method which includes an electrochemical anodization technique followed by electrochemical deposition. The synthesized high quality graphitic carbon dots can act as sensitizers to extend the spectral range of light absorption towards the full solar spectrum. It is confirmed that TiO2 NTAs anchored with CDs (CDs/TiO2 NTAs) display greatly improved photocatalytic activity and excellent photocatalytic stability. By tuning the light absorption of the TiO2 NTAs, the utilization of light in charge generation and separation is well synergized with the CDs for enhanced photocatalytic pollutant degradation and water splitting, achieving significantly improved rates of photocatalytic degradation and H2 production in the visible and full spectra, respectively.

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.

An ultrasonication-assisted in situ deposition strategy was utilised to uniformly decorate plasmonic Ag nanoparticles on vertically aligned TiO2 nanotube arrays (NTAs) to construct a Ag@TiO2 NTA composite. The Ag nanoparticles act as efficient surface plasmon resonance (SPR) photosensitizers to drive photocatalytic water splitting under visible light irradiation. The Ag nanoparticles were uniformly deposited on the surface and inside the highly oriented TiO2 nanotubes. The visible-light-driven hydrogen production activities of silver nanoparticle anchored TiO2 nanotube array photocatalysts were evaluated using methanol as a sacrificial reagent in water under a 500 W Xe lamp with a UV light cutoff filter (λ ≥ 420 nm). It was found that the hydrogen production rate of the Ag@TiO2 NTAs prepared with ultrasonication-assisted deposition for 5 min was approximately 15 times higher than that of its pristine TiO2 NTAs counterpart. The highly efficient photocatalytic hydrogen evolution is attributed to the SPR effect of Ag for enhanced visible light absorption and boosting the photogenerated electron–hole separation/transfer. This strategy is promising for the design and construction of high efficiency TiO2 based photocatalysts for solar energy conversion.

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.

Highly flexible and porous films with the ability to load various nanoscale adsorbents are of particular importance in the purification field. Herein, we report the sustainable and large-scale fabrication of a porous and flexible hybrid film based on the graphene oxide/hyphae interaction at a relatively low temperature of 130 °C. Under identical conditions, such films cannot be constructed with solely graphene oxide or hyphae. Moreover, through the addition of nanoscale building blocks [e.g., nanoscale poly(m-phenylenediamine) (PmPD) adsorbents] in the interaction process, the nanoparticles can be in situ loaded into the film. According to FTIR and XPS analyses, the film formation mechanisms mainly involve redox and cross-linking reactions between graphene oxide and fungus hyphae. In a proof-of-concept study, a PmPD nanoparticle-loaded hybrid film was used as a superior key component to build a flow-through adsorption device that displayed a promising adsorption performance toward dye pollutants.Keywords: adsorption; film; fungus; graphene oxide; nanoparticles;

An ultrasonication-assisted successive ionic layer adsorption and reaction (SILAR) strategy was developed for uniform deposition of high density p-type Bi2O3 quantum dots on n-type TiO2 nanotube arrays (Bi2O3@TiO2 NTAs), which were constructed by electrochemical anodization in ethylene glycol containing the electrolyte. Compared with pristine TiO2 NTAs, the Bi2O3 quantum dots sensitized TiO2 NTAs exhibited highly efficient photocatalytic degradation of methyl orange (MO). The kinetic constant of Bi2O3@TiO2 NTAs prepared by an ultrasonication-assisted SILAR process of 4 cycles was 1.95 times higher than that of the pristine TiO2 NTA counterpart. The highly efficient photocatalytic activity is attributed to the synergistic effect between the formation of a uniform p–n heterojunction with high-density for enhancing light absorption and facilitating photogenerated electron–hole separation/transfer. The results suggest that Bi2O3@TiO2 p–n heterojunction nanotube arrays are very promising for enhancing the photocatalytic activity and open up a promising strategy for designing and constructing high efficiency heterogeneous semiconductor photocatalysts.

A novel femtosecond laser patterning technique is reported to construct a three-dimensional (3D) wettability pattern on a superhydrophobic TiO2 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.

A combination of electrodeposition and carbonation techniques was adopted to deposit reduced graphene oxide films on TiO2 nanotube arrays (RGO-TiO2 NTAs), which were prepared by two-step electrochemical anodization in ethylene glycol system. The RGO-TiO2 NTAs exhibit a significantly enhanced photocatalytic degradation ability for methyl orange (MO) than pristine TiO2 NTAs and annealed TiO2 NTAs under the same conditions. The kinetic constant for the photocatalytic degradation of MO using RGO-TiO2 NTAs prepared by annealing in an Ar atmosphere at 550 °C was 2.9 times higher than that using the pristine TiO2 NTAs. The highly efficient photocatalytic activity is attributed to the enhanced separation efficiency of photoinduced electrons and holes, the red shift of the absorption band in the UV region as well as the strong adsorption ability of RGO towards MO molecules. This proposed facile strategy provides a promising avenue to synthesize novel TiO2 NTAs-based hybrid materials for efficient photocatalysis in the future.

Inspired by the surface geometry and composition of the lotus leaf with its self-cleaning behavior, in this work, a TiO2@fabric composite was prepared via a facile strategy for preparing marigold flower-like hierarchical TiO2 particles through a one-pot hydrothermal reaction on a cotton fabric surface. In addition, a robust superhydrophobic TiO2@fabric was further constructed by fluoroalkylsilane modification as a versatile platform for UV shielding, self-cleaning and oil–water separation. The results showed TiO2 particles were uniformly distributed on the fibre surface with a high coating density. In comparison with hydrophobic cotton fabric, the TiO2@fabric exhibited a high superhydrophobic activity with a contact angle of ∼160° and a sliding angle lower than 10°. The robust superhydrophobic fabric had high stability against repeated abrasion without an apparent reduction in contact angle. The as-prepared composite TiO2@fabric demonstrated good anti-UV ability. Moreover, the composite fabric demonstrated highly efficient oil–water separation due to its extreme wettability contrast (superhydrophobicity/superoleophilicity). We expect that this facile process can be readily and widely adopted for the design of multifunctional fabrics for excellent anti-UV, effective self-cleaning, efficient oil–water separation, and microfluidic management applications.

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.

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.

Inspired by the surface geometry and composition of the lotus leaf with its self-cleaning behavior, in this work, a TiO2@fabric composite was prepared via a facile strategy for preparing marigold flower-like hierarchical TiO2 particles through a one-pot hydrothermal reaction on a cotton fabric surface. In addition, a robust superhydrophobic TiO2@fabric was further constructed by fluoroalkylsilane modification as a versatile platform for UV shielding, self-cleaning and oil–water separation. The results showed TiO2 particles were uniformly distributed on the fibre surface with a high coating density. In comparison with hydrophobic cotton fabric, the TiO2@fabric exhibited a high superhydrophobic activity with a contact angle of ∼160° and a sliding angle lower than 10°. The robust superhydrophobic fabric had high stability against repeated abrasion without an apparent reduction in contact angle. The as-prepared composite TiO2@fabric demonstrated good anti-UV ability. Moreover, the composite fabric demonstrated highly efficient oil–water separation due to its extreme wettability contrast (superhydrophobicity/superoleophilicity). We expect that this facile process can be readily and widely adopted for the design of multifunctional fabrics for excellent anti-UV, effective self-cleaning, efficient oil–water separation, and microfluidic management applications.

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.

A novel femtosecond laser patterning technique is reported to construct a three-dimensional (3D) wettability pattern on a superhydrophobic TiO2 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.

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.

A combination of electrodeposition and carbonation techniques was adopted to deposit reduced graphene oxide films on TiO2 nanotube arrays (RGO-TiO2 NTAs), which were prepared by two-step electrochemical anodization in ethylene glycol system. The RGO-TiO2 NTAs exhibit a significantly enhanced photocatalytic degradation ability for methyl orange (MO) than pristine TiO2 NTAs and annealed TiO2 NTAs under the same conditions. The kinetic constant for the photocatalytic degradation of MO using RGO-TiO2 NTAs prepared by annealing in an Ar atmosphere at 550 °C was 2.9 times higher than that using the pristine TiO2 NTAs. The highly efficient photocatalytic activity is attributed to the enhanced separation efficiency of photoinduced electrons and holes, the red shift of the absorption band in the UV region as well as the strong adsorption ability of RGO towards MO molecules. This proposed facile strategy provides a promising avenue to synthesize novel TiO2 NTAs-based hybrid materials for efficient photocatalysis in the future.

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.

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.

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.