Highly customized porous TiO2-PANI nanoparticles with excellent photocatalytic efficiency for dye degradation.

The present work encompasses a simple strategy to synthesize highly porous TiO2 by incorporating PANI polymer into the sol-gel chemistry of Titanium dioxide/Titanium (IV)-iso-propoxide (TiO2/TTIP). A series of TiO2 samples by varying wt.% of PANI, have been synthesized. A probable growth mechanism has been presented for the formation of a porous ginger-like nanostructure of TiO2-PANI (TP). HRTEM images reveal that the particle size range is 6-16 nm for pristine TiO2 and 5-13 nm for TP samples. XPS analysis confirms the presence of the hydrogen bonds in-between surface hydroxyl groups (Ti-OH) of TiO2 and the protonated nitrogen of PANI. UV-visible absorption study reveals a small shift towards longer wavelength for TP8 sample than that of pristine TiO2 (λmax = 314 nm) as well as reduction in Eg value from 3.02 eV to 2.89 eV. FTIR results confirm the successful interaction of PANI and TiO2. BJH and BET analysis confirms an increase of porosity in TP8 sample with an average pore volume of 0.36 cm3 g-1. High photocatalytic activity (98.77%) towards Methylene blue dye degradation is observed for TP8 sample having 8 wt% of PANI and it is explained through the combined effect of structural porosity of TiO2 and synergic effect of PANI. The Kappa value at pH 11 (0.01372 min-1) is found to be 7.84-folds higher than that of the photocatalytic reaction at pH 3 (Kappa = 0.00175 min-1). While pristine TiO2 exhibits the minimum removal efficiency (89.57%) with Kappa of 0.00756 min-1. Kappa value of catalysis reaction for TP8 is found to be almost 2-fold higher than pristine TiO2. Quantum Yield value for TP8 is found to be 3.59 × 10-4 molecules photon-1. This high Quantum Yield value of present photocatalytic system explicates the low energy consumption for the treatment of textile dye pollutant. Additionally, STY value (1.79 × 10-5 molecules photon-1 mg-1) confirms the outstanding mineralization strength of TP8 by a unit mass for high amounts of MB dye per unit time. Thus, the present study offers an excellent photocatalyst i.e., TP8 having 8 wt% of PANI for the degradation of MB dye.

Thermal and Optical Properties of Porous Nanomesh Structures for Sensitive Terahertz Bolometric Detection.

Terahertz (THz) electromagnetic waves are attractive for use in nondestructive and biocompatible sensing applications. Thermal sensors are widely used for THz detection owing to the small photon energies of THz radiation, where this requires materials with low thermal conductivity and a small heat capacity to ensure the sensitive and fast operation of the sensors. In this study, we investigated the thermal and optical properties of porous nanomesh structures for sensitive THz bolometric detection. Nanometer (nm)-scale hole array structures were formed on gallium arsenide (GaAs) microelectromechanical system (MEMS) beams to improve their thermal properties. The thermal conductance of the porous MEMS beams was obtained by measuring their thermal bandwidths; it was found to decrease by as much as ~90% when the porosity (P) of the porous nanostructure was increased to ~0.69. We also measured the THz absorptance of the porous hole array structure. The results show that although the porous nanostructure has a much smaller area than the bulk material, it maintained a high coefficient of THz absorptance because the featured size was much smaller than the THz wavelength. The measured absorptance agreed well with that calculated by using the Drude model. These results demonstrate that the porous nanomesh structure is promising for developing highly sensitive THz thermal sensors.

Synthesis of MnO/C/Co3O4 nanocomposites by a Mn2+-oxidizing bacterium as a biotemplate for lithium-ion batteries.

The biotemplate and bioconversion strategy represents a sustainable and environmentally friendly approach to material manufacturing. In the current study, biogenic manganese oxide aggregates of the Mn2+-oxidizing bacterium Pseudomonas sp. T34 were used as a precursor to synthesize a biocomposite that incorporated Co (CMC-Co) under mild shake-flask conditions based on the biomineralization process of biogenic Mn oxides and the characteristics of metal ion subsidies. X-ray photoelectron spectroscopy, phase composition and fine structure analyses demonstrated that hollow MnO/C/Co3O4 multiphase composites were fabricated after high-temperature annealing of the biocomposites at 800°C. The cycling and rate performance of the prepared anode materials for lithium-ion batteries were compared. Due to the unique hollow structure and multiphasic state, the reversible discharge capacity of CMC-Co remained at 650 mAh g-1 after 50 cycles at a current density of 0.1 Ag-1, and the coulombic efficiency remained above 99% after the second cycle, indicating a good application potential as an anode material for lithium-ion batteries.

Dendrite-Embedded Platinum-Nickel Multiframes as Highly Active and Durable Electrocatalyst toward the Oxygen Reduction Reaction.

Pt-based nanoframe catalysts have been explored extensively due to their superior activity toward the oxygen reduction reaction (ORR). Herein, we report the synthesis of Pt-Ni multiframes, which exhibit the unique structure of tightly fused multiple nanoframes and reinforced by an embedded dendrite. Rapid reduction and deposition of Ni atoms on Pt-Ni nanodendrites induce the alloying/dealloying of Pt and Ni in the overall nanostructures. After chemical etching of Ni, the newly formed dendrite-embedded Pt-Ni multiframes show an electrochemically active surface area (ECSA) of 73.4 m2 gPt-1 and a mass ORR activity of 1.51 A mgPt-1 at 0.93 V, which is 30-fold higher than that of the state-of-the-art Pt/C catalyst. We suggest that high ECSA and ORR performances of dendrite-embedded Pt-Ni multiframes/C can be attributed to the porous nanostructure and numerous active sites exposed on surface grain boundaries and high-indexed facets.

Boosting Electrochemical Hydrogen Evolution of Porous Metal Phosphides Nanosheets by Coating Defective TiO2 Overlayers.

Nonprecious transition metal phosphides (TMPs) have emerged as robust electrocalysts for the hydrogen evolution reaction (HER). However, the TMPs suffer from low activity for water dissociation, which greatly limits the efficiency for alkaline HER. Here, a facile yet robust strategy is reported to boost the HER of metal phosphides by coating defective TiO2 overlayers. The oxygen vacancies (Ov ) on defective TiO2 overlayers are found to possess high activity for adsorption and dissociation of water, thereby significantly promoting the initial Volmer step of HER to generate the reactive hydrogen atoms. Moreover, the porous (Co, Ni)2 P (i.e., Co2 P and Ni2 P) nanosheets provide enough active sites for adsorption and recombination of reactive hydrogen atoms to produce hydrogen gas. The catalytic synergy of (Co, Ni)2 P and Ov coupled with the hierarchically porous structure renders the porous (Co, Ni)2 P@0.1TiO2 nanosheet arrays excellent electrocatalysts for HER, showing a small overpotential (92 mV) to yield a current density of 10 mA cm-2 , a small Tafel slope (49 mV dec-1 ), and an outstanding stability. This work demonstrates a surface decoration route for enhancing the activity of nonprecious metal-based electrocatalysts for HER.

Colloids of Holey Gd2 O3 Nanosheets Converted from Exfoliated Gadolinium Hydroxide Layers.

This paper proposes a confined solid-state conversion approach using layered metal-hydroxides for the production of a colloidal suspension of porous 2D crystalline metal oxide layers with superior electrochemical H2 O2 sensing performance. This study investigates the conversion chemistry of delaminated layers of gadolinium hydroxide (LGdH), [Gd2 (OH)5 ]+ , encapsulated in a silica nanoshell that provides an antistacking and antisintering environment during the phase-transition at high temperature. Thermal treatment of the LGdH layers within the protected environment results in a dimensionally confined phase-transition into crystalline Gd2 O3 nanosheets with an isomorphic 2D structure. Furthermore, annealing at higher temperatures leads to the evolution of in-plane mesoporous structure on the Gd2 O3 nanosheet. Based on insight acquired from in-depth investigation, the evolution of in-plane porosity proceeds through the in-plane dominant silicate-formation reaction at the interface with the surrounding silica shell. Their 2D-anisotropic and mesoporous morphological features are preserved, producing a colloidal suspension of holey nanosheets that can be used to fabricate a thin and porous film through wet-coating deposition. This study also demonstrates the superior electrochemical H2 O2 sensing ability of the resultant porous Gd2 O3 film, which represents a ≈1000- and 10-fold enhancement of the detection limit and sensitivity, respectively, in comparison to previously reported Gd2 O3 films.

Nanocrystal-Assembled Porous Na3 MgTi(PO4 )3 Aggregates as Highly Stable Anode for Aqueous Sodium-Ion Batteries.

Aqueous sodium-ion batteries (SIBs) represent a class of green electrochemical technology for large-scale storage of sustainable energies such as wind power and solar radiation, owing to their low cost, environmental friendliness, and reliable safety. However, there is still lack of available anode materials for aqueous SIBs. Herein, nanocrystal-assembled porous Na3 MgTi(PO4 )3 aggregates are reported as novel anode material for aqueous SIBs. The crystal structure, morphological features, and electrochemical properties have been analyzed with X-ray diffraction, scanning electron microscopy, transition electron microscopy, cyclic voltammetry, and charge/discharge measurements. As revealed, the material possesses a porous nanostructure composed of 5 nm nanocrystals and mesoporous channels. During Na-insertion/extraction, it undergoes a one-step single-phase reaction mechanism through reversible electrochemistry of the Ti4+ /Ti3+ redox couple, showing a rechargeable capacity of 54 mAh g-1 and an average working potential of -0.63 V (vs. Ag/AgCl) at 0.2 C. More importantly, good rate capacity (33 mAh g-1 at 4 C) and excellent cycling performance (94.2 % capacity retention after 100 cycles at 0.5 C) are achieved due to the unique porous nanostructure and robust compositional framework. The finding in this work would create new opportunities for design of low-cost, long-cycling aqueous SIBs.

Sonochemical-assisted method for efficient synthesis of Cu-MOF and evaluating its antibacterial properties.

Sonochemical-assisted method was used to synthesize copper metal-organic frameworks (Cu-MOF) nanostructures. The final products were examined by related techniques such as XRD patterns, SEM image, BET N2 adsorption/desorption technique and FTIR spectrum. Microtiter plates microbiological assay were used to investigate antibacterial properties and the results were analyzed using ANOVA and Tukey HSD tests. The results showed that Cu-MOF nanostructures have a mesoporous nature with an average particle size distribution around 60 nm. The final product had the property of preventing the growth of all tested bacteria in certain concentrations. Minimum Inhibitory Concentration (MIC) values were observed in the range of 30-100 ppm. It was also discovered that this nanostructure can not kill bacteria completely. In addition, the minimal inhibitory concentration for biofilm growth (MIC-B) of the nanostructure was investigated. The MIC-B analyzes demonstrated that the growth of bacterial biofilm decreased with increasing Cu-MOF concentration.

Highly dispersed g-C3N4 on well-designed three-dimensional porous nanostructured ZrO2 for high-performance photocatalytic degradation and H2 production.

A novel polymer-assisted freeze-drying method was adopted for preparing three-dimensional porous nanostructured ZrO2 (3DPZ) with macro self-supporting properties. Then, g-C3N4 was in-situ grown uniformly on the 3DPZ through a gas-solid reaction, forming 3D nanoporous ZrO2/g-C3N4 heterojunctions (3DP/ZC) with different g-C3N4 loadings that retained self-supporting characteristics. The kapp value of Rhodamine B (RhB) degradation and H2 evolution rate of the 3DP/ZC-2 under visible light reached 0.035 min-1 and 1013.1 µmol h-1 g-1, which were 19.6 and 6.6 times higher than pure g-C3N4, respectively. The ZrO2 nanoparticles (ZNps) prepared via freeze-drying, but without polymer precursor, were used as support to form ZrO2/g-C3N4 nanoparticles (ZCNps-2) for comparison study. The RhB degradation rate and H2 evolution rate of the 3DP/ZC-2 under visible light were about 3.7 and 5.3 times higher than ZCNps-2. Their enhanced photocatalytic activity could be attributed to their unique 3D heterointerface with matched energy bands for rapid charge separation and transfer and a hierarchical porous structure for mass transfer and surface reaction processes. The scavenger trapping and ESR measurements confirmed that the primary reactive radicals for degradation were superoxide radical ions (⋅O2-), hydroxyl radicals (⋅OH), and photogenerated holes (h+). The pH-dependent photocatalytic degradation activity originated from the H+-related ⋅OH conversion reaction. Besides, the macro self-supporting nature could provide excellent separability and recyclability, and self-supporting membranes were also constructed and demonstrated as stable and recyclable photocatalysts. This work provides a new routine for designing 3D-heterojunctions as new kinds of functional materials for applications in environmental remediation and green energy production.

Natural kaolinite-based hierarchical porous microspheres as effective and highly recyclable adsorbent for removal of cationic dyes.

The development of efficient, recyclable, and environment-friendly adsorbent for wastewater remediation is considered a challenge. In this study, a hierarchical porous kaolinite microsphere (HPKS) with three-dimensional (3D) structure was fabricated based on natural-layered kaolinite mineral via an environmentally friendly direct hydrothermal strategy. Characterization results revealed that HPKS microsphere with 3D hierarchical porous structure was constructed with numerous nanospheres which are assembled by ultrafine aluminosilicate flakes. HPKS exhibited negative charge feature ranging from strong acid to high alkaline solution. The influence of contact time, solution pH, initial dye concentration, adsorbent dosage, and foreign ions on methylene blue (MB) adsorption capability was systematically investigated. The synthesized HPKS with higher specific surface area (250.6 m2/g) shows an outstanding adsorption capacity towards MB (411.8 mg/g) and excellent selectivity for cationic MB dyes over anionic methyl orange and competitive metal ions. The adsorption kinetic experiment results fit very well with the pseudo-second-order model and reflect the fast adsorption rate of MB on HPKS. The sorption isotherm study reveals the chemisorption of electrostatic attraction between the cationic MB molecules and the negative charged surfaces of HPKS. More importantly, the MB removal efficiency is more than 99% in a broad range of solution pH value. The adsorption capacities of HPKS can be easily recovered by calcination at 600 °C to remove the adsorbed dyes and without obvious diminishment even after six successive cycles. Therefore, the HPKS is a cost-effective and environmentally friendly adsorbent which has is promising to use in practical applications.

Ultrathin Carbon-Coated Porous TiNb2O7 Nanosheets as Anode Materials for Enhanced Lithium Storage.

TiNb2O7 has been considered as a promising anode material for next-generation high power lithium ion batteries for its relatively high theoretical capacity, excellent safety and long cycle life. However, the unsatisfactory electrochemical kinetics resulting from the intrinsic sluggish electron transport and lithium ion diffusion of TiNb2O7 limit its wide application. Morphology controlling and carbon coating are two effective methods for improving the electrochemical performance of electrode materials. Herein, an ultrathin carbon-coated porous TiNb2O7 nanosheet (TNO@C) is successfully fabricated by a simple and effective approach. The distinctive sheet-like porous structure can shorten the transport path of ions/electrons and provide more active sites for electrochemical reaction. The introduction of nanolayer carbon can improve electronic conductivity and increase the specific surface area of the porous TiNb2O7 nanosheets. Based on the above synergistic effect, TiNb2O7@C delivers an initial discharge capacity of 250.6 mAh g-1 under current density of 5C and can be maintained at 206.9 mAh g-1 after 1000 cycles with a capacity retention of 82.6%, both of which are superior to that of pure TiNb2O7. These results well demonstrate that TiNb2O7@C is a promising anode material for lithium ion batteries.

Dendrite-Free and Ultra-Long-Life Lithium Metal Anode Enabled via a Three-Dimensional Ordered Porous Nanostructure.

Constructing a stable non-dendritic lithium metal anode is the key to the development of high-energy batteries in the future. Herein, we fabricated nitrogen-doped carbon photonic crystals in situ in the macropores of carbon papers as a porous skeleton and confined hosts for metallic lithium. The large specific surface area of the carbon photonic crystal reduces the current density of the electrode. The three-dimensional ordered microstructure promotes uniform charge distribution and uniform lithium deposition and inhibits the volume expansion of metallic lithium. The as-prepared lithium metal anode exhibits prominent electrochemical performance with a small hysteresis of less than 95 mV beyond 180 cycles at an extremely high current density of 15 mA cm-2. When the as-prepared lithium metal anode is coupled with the sulfur cathode, the obtained full cell displays enhanced capacitive properties and cycle life. Compared with the bare Li anode, the full cell exhibits more than 300 cycles of cell life and a 70 mA h g-1 higher discharge capacity.

In Vitro bioactivity, biocompatibility and corrosion resistance of multi-ionic (Ce/Si) co-doped hydroxyapatite porous coating on Ti-6Al-4 V for bone regeneration applications.

Dual-doped hydroxyapatite (Ce4+/Si4+ doped HAP) coating with admirable bacterial resistance and enriched bioactivity was fabricated via spin-coating technique. In this study, Ce/Si co-doped hydroxyapatite was coated on Ti-6Al-4 V substrates as a triple layer with extreme centrifugal force (2000 RPM, 3000 RPM and 4000 RPM) to improve the biological performance of the coating in terms of enhanced bone apposition. Further, the coated substrate was characterized by XRD, FTIR and SEM-EDS techniques. The contact angle of the coating was measured through the sessile drop method and in vitro biomineralization was carried out in SBF solution to predict the apatite formation on the surface of the coated implant. Pathogen restriction behaviour of the coating was studied using gram-negative and gram-positive bacteria such as Staphylococcus aureus, Bacillus subtilis, Escherichia coli and Pseudomonas aeruginosa respectively. Among these, gram-negative bacteria, Escherichia coli revealed greater inhibition than other bacteria. In vitro cell viability assay using MG-63 osteoblast cell was performed for the optimised coating acquired at 4000 RPM and the result showed excellent biocompatibility towards the cell line. Corrosion resistance behaviour of the coating using Polarization and EIS study exhibited excellent corrosion resistance. Therefore, based on the in vitro studies, the designed multifunctional coating can act as a potential biomaterial in the field of biomedical engineering.

Electron-Induced Perpendicular Graphene Sheets Embedded Porous Carbon Film for Flexible Touch Sensors.

Graphene-based materials on wearable electronics and bendable displays have received considerable attention for the mechanical flexibility, superior electrical conductivity, and high surface area, which are proved to be one of the most promising candidates of stretching and wearable sensors. However, polarized electric charges need to overcome the barrier of graphene sheets to cross over flakes to penetrate into the electrode, as the graphene planes are usually parallel to the electrode surface. By introducing electron-induced perpendicular graphene (EIPG) electrodes incorporated with a stretchable dielectric layer, a flexible and stretchable touch sensor with "in-sheet-charges-transportation" is developed to lower the resistance of carrier movement. The electrode was fabricated with porous nanostructured architecture design to enable wider variety of dielectric constants of only 50-µm-thick Ecoflex layer, leading to fast response time of only 66 ms, as well as high sensitivities of 0.13 kPa-1 below 0.1 kPa and 4.41 MPa-1 above 10 kPa, respectively. Moreover, the capacitance-decrease phenomenon of capacitive sensor is explored to exhibit an object recognition function in one pixel without any other integrated sensor. This not only suggests promising applications of the EIPG electrode in flexible touch sensors but also provides a strategy for internet of things security functions.

3D Porous Self-Standing Sb Foam Anode with a Conformal Indium Layer for Enhanced Sodium Storage.

Antimony (Sb) has been considered as a promising anode for sodium-ion batteries (SIBs) because of its high theoretical capacity and moderate working potential but suffers from the dramatic volume variations (∼250%), an unstable electrode/electrolyte interphase, active material exfoliation, and a continuously increased interphase impedance upon sodiation and desodiation processes. To address these issues, we report a unique three-dimensional (3D) porous self-standing foam electrode built from core-shelled Sb@In2O3 nanostructures via a continuous electrodepositing strategy coupled with surface chemical passivation. Such a hierarchical structure possesses a robust framework with rich voids and a dense protection layer (In2O3), which allow Sb nanoparticles to well accommodate their mechanical strain for efficiently avoiding electrode cracks and pulverization with a stable electrode/electrolyte interphase upon sodiation/desodiation processes. When evaluated as an anode for SIBs, the prepared nanoarchitectures exhibit a high first reversible capacity (641.3 mA h g-1) and good cyclability (456.5 mA h g-1 after 300 cycles at 300 mA g-1), along with superior high rate capacity (348.9 mA h g-1 even at 20 A g-1) with a first Coulomb efficiency as high as 85.3%. This work could offer an efficient approach to improve alloying-based anode materials for promoting their practical applications.

Nitrogen defects-rich porous graphitic carbon nitride for efficient photocatalytic hydrogen evolution.

Graphitic carbon nitride (CN) is considered as a promising photocatalyst for solar energy conversion. However, low specific surface area and fast electrons and holes recombination restrict the photocatalytic applications of CN material. Herein, a nitrogen defect-rich and highly porous CN nanostructure (CN-LT) was prepared by combining two strategies, i.e., LiOH treatment and heat etching. The as-prepared nitrogen defect-rich porous CN-LT not only has a larger specific surface area, as compared with pristine CN, but also the photogenerated electron-hole separation was boosted remarkably. Using Pt as a co-catalyst and lactic acid aqueous solutions as sacrificial reagent under visible light irradiation (λ > 400 nm), the hydrogen evolution reaction (HER) rate for CN-LT (1.54 mmol h-1 g-1) was 19.25 times higher than that for pristine CN (0.08 mmol h-1 g-1). While subjecting pristine CN to heat etching under the same experimental conditions, excepting the use of LiOH (CN-T), an increase in HER rate of 7.5 times was obtained. Our current study may shed more light on the enhancement of the photocatalytic activity of bulk CN materials by altering their microstructure.

A high-performance non-enzymatic electrochemical hydrazine sensor based on NiCo2S4 porous sphere.

A non-enzymatic electrochemical sensor-NiCo2S4/GCE was constructed for sensitive and selective detection of hydrazine (N2H4), which was designed based on porous nanostructure and synthesized through a facile hydrothermal method. The nanocomposite has been characterized using a series of characterizations such as X-ray powder diffraction (XRD), scanning electron microscopic (SEM), transmission electron microscopy (TEM), showing the porous NiCo2S4 sphere was made of interconnected nanoparticles with porous structure. Electrochemical measurements revealed that the porous NiCo2S4 sphere based sensor exhibited an excellent voltammetric response towards the N2H4 oxidation with a wide linear range of 1.7 µM to 7.8 mM, a low detection limit of 0.6 µM (S/N = 3), a sensitivity of 179.1 µA mM-1 cm-2. Moreover, determinations of N2H4 in tap water samples were carried out by standard addition. Acceptable results with relative standard deviation of 2.1-3.0% and recovery of 95.20-103.6% were obtained for five parallel measurements. Therefore, NiCo2S4/GCE promised to be a new platform for electrochemical detection of N2H4.

Porous Hybrid Nanofibers Comprising ZnSe/CoSe2/Carbon with Uniformly Distributed Pores as Anodes for High-Performance Sodium-Ion Batteries.

Well-designed porous structured bimetallic ZnSe/CoSe2/carbon composite nanofibers with uniformly distributed pores were prepared as anodes for sodium-ion batteries by electrospinning and subsequent simple heat-treatment processes. Size-controlled polystyrene (PS) nanobeads in the electrospinning solution played a key role in the formation and uniform distribution of pores in the nanofiber structure, after the removal of selected PS nanobeads during the heat-treatment process. The porous ZnSe/CoSe2/C composite nanofibers were able to release severe mechanical stress/strain during discharge-charge cycles, introduce larger contact area between the active materials and the electrolyte, and provide more active sites during cycling. The discharge capacity of porous ZnSe/CoSe2/C composite nanofibers at the 10,000th cycle was 297 mA h g-1, and the capacity retention measured from the second cycle was 81%. The final rate capacities of porous ZnSe/CoSe2/C composite nanofibers were 438, 377, 367, 348, 335, 323, and 303 mA h g-1 at current densities of 0.1, 0.5, 1, 3, 5, 7, and 10 A g-1, respectively. At the higher current densities of 10, 20, and 30 A g-1, the final rate capacities were 310, 222, and 141 mA h g-1, respectively.

Superior Hydrogen Sensing Property of Porous NiO/SnO2 Nanofibers Synthesized via Carbonization.

In this paper, the porous NiO/SnO2 nanofibers were synthesized via the electrospinning method along with the carbonization process. The characterization results show that the pristine SnO2-based nanofibers can form porous structure with different grain size by carbonization. The hydrogen gas-sensing investigations indicate that the NiO/SnO2 sensor exhibits more prominent sensing properties than those of pure SnO2 sensor devices. Such enhanced performance is mainly attributed to the porous nanostructure, which can provide large active adsorption sites for surface reaction. Moreover, the existence of p-n heterojunctions between NiO and SnO2 also plays a key role in enhancing gas-sensing performances. Finally, the H2 sensing mechanism based on the NiO/SnO2 nanocomposite was proposed for developing high-performance gas sensor devices.

Hybrid Alginate@TiO2 Porous Microcapsules as a Reservoir of Animal Cells for Cell Therapy.

The number of patients suffering from diseases linked with hormone deficiency (e.g., type 1 diabetes mellitus) has significantly increased in recent years. As organ transplantation presents its limits, the design of novel robust devices for cell encapsulation is of great interest. The current study reports the design of a novel hybrid alginate microcapsule reinforced by titania via a biocompatible synthesis from an aqueous stable titania precursor (TiBALDH) and a cationic polyamine (PDDAC) under mild conditions. The biocompatibility of this one-pot synthesis was confirmed by evaluation of the cytotoxicity of the precursor, additive, product, and by-product. The morphology, structure, and properties of the obtained hybrid microcapsule were characterized in detail. The microcapsule displayed mesoporous, which was a key parameter to allow the diffusion of nutrients and metabolites and to avoid the entry of immune defenders. The hybrid microcapsule also showed enhanced mechanical stability compared to the pure alginate microcapsule, making it an ideal candidate as a cell reservoir. HepG2 model cells encapsulated in the hybrid microcapsules remained intact for 43 days as highlighted by fluorescent viability probes, their oxygen consumption, and their albumin secretion. The study provides a significant progress in the conception of the robust and biocompatible reservoirs of animal cells for cell therapy.