Engineering hierarchical FeS2/TiO2 nanotubes on Ti mesh as a tailorable flow-through catalyst belt for all-day-active degradation of organic pollutants and pathogens.

The increasing organic and microbiological pollutions in fresh water caused by human activities and industrial development have become a global concern nowadays. In this study, three-dimensional (3D) hierarchical FeS2/TiO2 structures with nanotube geometries were grown on a Ti mesh (M-TNTAs-FeS2). Benefitting from the abundant available reactive sites on the open 3D micro/nanoporous structures, excellent photocatalytic activity of FeS2/TiO2 heterostructure in solar light, and satisfactory Fenton activity of FeS2, the obtained M-TNTAs-FeS2 exhibits outstanding performance as an all-day-active catalyst. Importantly, flexible meshes can be easily tailored and enveloped into fluorinated ethylene propylene (FEP) pockets in a series as a flow-through belt for large-capacitance applications (998 L m-2 at a flow rate of 417 L m-2 h-1 for a four-pockets belt), as indicated by the degradation of azo dyes, antibiotics, pesticides, and pathogens. This study may inspire a new tailorable catalyst design for a promising point-of-use purification device.

Asymmetric coupling of Au nanospheres on TiO2 nanochannel membranes for NIR-gated artificial ionic nanochannels.

Au nanoparticles were asymmetrically fabricated at one tip of TiO2 nanochannels by combining a photocatalytic reaction and limited penetration of light. Using the asymmetrical nanochannel-based membrane as a plasma absorber, near-infrared-gated artificial ionic nanochannels were designed.

An anion exchange reaction: an effective approach to prepare alloyed Co-Fe bimetallic disulfide for improving the electrocatalytic activity.

A mild anion exchange approach is proposed for the synthesis of alloyed Co-Fe bimetallic disulfide. Abundant structural disorders and tunable compositions are effectively induced by the anion exchange process. The alloyed Co-Fe bimetallic disulfide exhibits a low overpotential of 205 mV to reach a current density of 100 mA cm-2 in an acidic electrolyte, which is significantly improved compared to the performance of individual disulfide. It is believed that this work paves a new strategy for the synthesis of bimetallic compounds and highlights the importance of tuning the catalyst composition for achieving high catalytic performance.

Boosting the oxygen evolution reaction performance of CoS2 microspheres by subtle ionic liquid modification.

Hierarchical CoS2 microspheres were prepared and modified with a cationic ionic liquid (IL). The composite shows enhanced oxygen evolution reaction (OER) performances attributed to the fact that the OER equilibrium is driven forward by the IL, according to Le Chatelier's principle, and by the electrostatic affinity generated at the CoS2/electrolyte interface.

Pt-Decorated g-C3N4/TiO2 Nanotube Arrays with Enhanced Visible-Light Photocatalytic Activity for H2 Evolution.

Aligned TiO2 nanotube layers (TiNTs) grown by self-organizing anodization of a Ti-substrate in a fluoride-based electrolyte were decorated with graphitic-phase C3N4 (g-C3N4) via a facile chemical vapor deposition approach. In comparison with classical TiO2 nanotubes (anatase), the g-C3N4/TiNTs show an onset of the photocurrent at 2.4 eV (vs. 3.2 eV for anatase) with a considerably high photocurrent magnitude in the visible range. After further decoration with Pt nanoparticles, we obtained a visible-light responsive platform that showed, compared with g-C3N4-free TiNTs, a strong enhancement for photoelectrochemical and bias-free H2 evolution (15.62 µLh-1 cm-2), which was almost a 98-fold increase in the H2 production rate of TiNTs (0.16 µLh-1 cm-2). In a wider context, the g-C3N4-combined 3 D nanoporous/nanotubular structure thus provides a platform with significant visible-light response in photocatalytic applications.

Graphitic C3 N4 -Sensitized TiO2 Nanotube Layers: A Visible-Light Activated Efficient Metal-Free Antimicrobial Platform.

Herein, we use a facile procedure to graft a thin graphitic C3N4 (g-C3N4) layer on aligned TiO2 nanotube arrays (TiNT) by a one-step chemical vapor deposition (CVD) approach. This provides a platform to enhance the visible-light response of TiO2 nanotubes for antimicrobial applications. The formed g-C3N4/TiNT binary nanocomposite exhibits excellent bactericidal efficiency against Escherichia coli (E. coli) as a visible-light activated antibacterial coating, without the use of additional bactericides.

Nitrogen-doped carbon nanospheres derived from cocoon silk as metal-free electrocatalyst for glucose sensing.

Nitrogen-doped carbon materials have attracted tremendous attention because of their high activity in electrocatalysis. In the present work, cocoon silk -- a biomass material is used to prepare porous carbon fibers due to its abundant nitrogen content. The as-prepared carbon microfibers have been activated and disintegrated into carbon nanospheres (CNS) with a diameter of 20--60 nm by a simple nitric acid refluxing process. Considering their excellent electrocatalytic activity towards the reduction of oxygen, the CNS modified electrodes are further applied in the construction of glucose amperometric biosensor using glucose oxidase as a model. The proposed biosensor exhibits fast response, high sensitivity, good stability and selectivity for glucose detection with a wide linear range from 79.7 to 2038.9 µM, and a detection limit of 39.1 µM. The performance is comparable to leading literature results indicating a great potential for electrochemical sensing application.

Carbon cladded TiO2 nanotubes: fabrication and use in 3D-RuO2 based supercapacitors.

In this work we introduce a facile procedure that allows a highly conformal coating of self-organized TiO2 nanotubes (NTs) with a graphite-like thin carbon layer. This provides a platform to enhance the functionality of TiO2 nanotubes for a wide range of applications. Here we show that such modified nanotubes can serve as a 3D scaffold for an ideal decoration with RuO2 nanoparticles. Used as 3D pseudocapacitor electrode, capacitance values of up to 80 times higher than plain TiO2 NTs, and a very high yield of utilization of RuO2 (872 F g(-1)) and excellent long-term cycling stability can be reached.

Development of amperometric glucose biosensor based on Prussian Blue functionlized TiO2 nanotube arrays.

Amperometric biosensors consisting of oxidase and peroxidase have attracted great attention because of their wide application. The current work demonstrates a novel approach to construct an enzymatic biosensor based on TiO2 nanotube arrays (TiNTs) as a supporting electrode on which Prussian Blue (PB)-an "artificial enzyme peroxidase" and enzyme glucose oxidase (GOx) have been immobilized. For this, PB nanocrystals are deposited onto the nanotube wall photocatalytically using the intrinsic photocatalytical property of TiO2, and the GOx/AuNPs nanobiocomposites are subsequently immobilized into the nanotubes via the electrodeposition of polymer. The resulting electrode exhibits a fast response, wide linear range, and good stability for glucose sensing. The sensitivity of the sensor is as high as 248 mA M(-1) cm(-2), and the detection limit is about 3.2 µM. These findings demonstrate a promising strategy to integrate enzymes and TiNTs, which could provide an analytical access to a large group of enzymes for bioelectrochemical applications including biosensors and biofuel cells.

Synthesis of magnetically separable Ag3PO4/TiO2/Fe3O4 heterostructure with enhanced photocatalytic performance under visible light for photoinactivation of bacteria.

Silver orthophosphate (Ag3PO4) is a low-band-gap photocatalyst that has received considerable research interest in recent years. In this work, the magnetic Ag3PO4/TiO2/Fe3O4 heterostructured nanocomposite was synthesized. The nanocomposite was found to exhibit markedly enhanced photocatalytic activity, cycling stability, and long-term durability in the photodegradation of acid orange 7 (AO7) under visible light. Moreover, the antibacterial film prepared from Ag3PO4/TiO2/Fe3O4 nanocomposite presented excellent bactericidal activity and recyclability toward Escherichia coli (E. coli) cells under visible-light irradiation. In addition to the intrinsic cytotoxicity of silver ions, the elevated bactericidal efficiency of Ag3PO4/TiO2/Fe3O4 can be largely attributed to its highly enhanced photocatalytic activity. The photogenerated hydroxyl radicals and superoxide ions on the formed Ag/Ag3PO4/TiO2 interfaces cause considerable morphological changes in the microorganism's cells and lead to the death of the bacteria.

One-step to prepare self-organized nanoporous NiO/TiO2 layers and its use in non-enzymatic glucose sensing.

A highly ordered nanoporous NiTi oxide layers were fabricated on Ti alloys with high Ni contents (50.6 at.%) by a combination of self-organizing anodization at 0°C and subsequent selective etching in H2O2. The key for successful formation of such layers is to sufficiently suppress the dissolve of NiO by applying lower temperature during anodization. The resulting nanoporous structure is connected and well-adhered, which exhibits a much higher electrochemical cycling stability in 0.1 M NaOH. Without further surface modification or the use of polymer binders, the layers can be behave as a low-cost, stable and sensitive platform in non-enzymatic glucose sensing.

Nickel hydroxide nanoparticle activated semi-metallic TiO(2) nanotube arrays for non-enzymatic glucose sensing.

Semi-metallic TiO2 nanotube arrays (TiOx Cy NTs) have been decorated uniformly with Ni(OH)2 nanoparticles without the aid of a polymer binder. The resulting hybrid nanotube arrays exhibit excellent catalytic activity towards non-enzymatic glucose electro-oxidation. The anodic current density of the glucose oxidation is significantly improved compared with traditional TiO2 nanotubes decorated with Ni(OH)2 . Moreover, the Ni(OH)2 /TiOx Cy NT-based electrode shows a fast response, high sensitivity, wide linear range, good selectivity and stability towards glucose electro-oxidation, and thus provides a promising and cost-effective sensing platform for non-enzymatic glucose detection.

Signal-amplified platform for electrochemical immunosensor based on TiO2 nanotube arrays using a HRP tagged antibody-Au nanoparticles as probe.

In this study, a novel signal-amplified electrochemical immunosensor was proposed by using TiO(2) nanotube (TiNT) arrays as the platform. Due to the distinct tubular features-large surface area, high pore volume and good electrochemical conductivity, the TiNT based electrodes exhibited excellent signal-amplified effects. gold nanoparticle (AuNP) was further utilized to bind horseradish peroxidase (HRP) tagged antibodies as recognition elements. Compared to the immunosensor based on either flat electrode, the immunosensors using TiNT layer as electrode showed higher amplified electrochemical signals from the catalytic reaction of HRP relative to hydrogen peroxide (H(2)O(2)). Under optimal conditions, the proposed immunosensor exhibited a good electrochemical behavior to antigen in a concentration range from 0.1 ng mL(-1) to 10(5) ng mL(-1) with a detection limit of 0.01 ng mL(-1). The results showed that the TiNT-based electrochemical immunosensing platform could provide a great potential in clinical application for detection of low-abundant proteins.

Biotemplated synthesis of Au nanoparticles-TiO2 nanotube junctions for enhanced direct electrochemistry of heme proteins.

Au nanoparticles (AuNPs) are assembled on TiO(2) nanotube (TiNT) arrays by combining a biotemplating method with the unique photocatalytic properties of TiO(2). The formed AuNPs-TiNT junctions show highly improved electrochemical conductivity and act as electrode materials to achieve the enhanced direct electrochemistry of heme proteins.

Signal Amplification Strategy Based on TiO2-Nanotube Layers and Nanobeads Carrying Quantum Dots for Electrochemiluminescent Immunosensors.

Self-organized TiO2-nanotube layers can be used for immunoassay-type sensing in combination with amplifying CdTe labels in a direct and very sensitive electrochemiluminescent (ECL) configuration. Key properties for this method are the conductivity of the TiO2 nanotubes, and their transparency for light emitted from the CdTe labels at approximately 2.4 eV. To demonstrate the potential of this platform, we constructed a sandwich-type immunoassay onto the TiO2-nanotube wall with a layer of (3-aminopropyl)triethoxysilane as the cross-linker for antibody immobilization. For the counter part of the sandwich, we created an amplification system consisting of TiO2 nanobeads carrying the secondary antibody and multiple CdTe quantum dots (multiQD). For antigen (IgG) detection, we find that this combination of 3D transparent electrode with multiQD labels allows for an ECL detection limit of 0.05 pg mL(-1) and a linearity of the signal in the range of 0.1-10(8) pg mL(-1).

Curcumin improves bone microarchitecture and enhances mineral density in APP/PS1 transgenic mice.

Alzheimer's disease and osteoporosis are often observed to co-occur in clinical practice. The present study aimed to evaluate the bone microarchitecture and bone mineral density (BMD) of the proximal tibia in APP/PS1 transgenic mice by micro-computed tomography (micro-CT), and to search for evidence that curcumin can be used to reduce bone mineral losses and treat osteoporosis after senile dementia in these transgenic mice. Three-month-old female mice were divided into the following groups (n=9 per group): wild-type mice (WT group); APP/PS1 transgenic mice (APP group); and APP/PS1 transgenic mice with curcumin treatment (APP+Cur group). Between 9 and 12 months of age, the APP+Cur group were administered curcumin orally (600ppm). CT scans of the proximal tibia were taken at 6, 9 and 12 months. At 6 months, there were little differences in the structural parameters. At 9 months, the APP groups displayed loss of bone volume ratio (BV/TV), trabecular thickness (Tb.Th), trabecular number (Tb.N) and connectivity density (Conn.D) and increases in trabecular separation (Tb.Sp) and geometric degree of anisotropy (DA) (P<0.05 or P<0.01), with significant changes in the BMD parameters. At 12 months, curcumin treatment led to constant increases in the trabecular bone mass of the metaphysis and clearly improved the BMD. By the same time, we measured the TNF-α and IL-6 in the serum among the different groups at 6, 9 and 12 months by enzyme-linked immunoassay(ELISA). These results suggest that APP/PS1 transgenic mice are susceptible to osteoporosis, and that curcumin can prevent further deterioration of the bone structure and produce beneficial changes in bone turnover. The change of inflammation cytokine, including TNF-α and IL-6, may play an important role in the mechanisms of action of curcumin, but the detail mechanism remains unknown.