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Li-rich Mn-based layered oxides with high specific capacity and operating voltages have become one of the most promising materials for lithium-ion batteries (LIBs). However, it still faces several issues of low initial Coulombic efficiency, poor electronic conductivity, and voltage fading due to oxygen release and transition metal rearrangement during cycling. In this study, Li1.2Mn0.54Ni0.13Co0.13O2 (LMR) cathode material with Na ion doping (LMNaR) and CeO2 nanoparticle surface modification (LMNaR@CeO2) is prepared to realize a synergistic modification effect. The doping of Na ions enlarges Li layer spacing to effectively promote the insertion and extraction of lithium ions, which makes the layered structure more stable to reduce the effect of the phase transition. And the CeO2 nanoparticle surface modification restrains the side reactions between electrode and electrolyte, stabilizes lattice oxygen, and eases oxygen release. As a result, LMNaR@CeO2 displays a specific capacity of 196 mAh g–1 after 100 cycles at 0.5 C with a capacity retention of 94% and a merely voltage decay of 0.16 V, which are much better than those of LMR with a specific capacity of 159.6 mAh g–1 and only a 79% capacity retention. Our strategy here provides a feasible approach for the development of Li-rich Mn-based cathode materials for long-lived LIBs. [ABSTRACT FROM AUTHOR]

Artificial solid electrolyte interphase (SEI) layers have been widely regarded as an effective protection for lithium (Li) metal anodes. In this work, an artificial SEI film consisting of dense Li 6.4 La 3 Zr 1.4 Ta 0.6 O 12 (LLZTO) nanoparticles and polymerized styrene butadiene rubber is designed, which has good mechanical and chemical stability to effectively prevent Li anode corrosion by the electrolyte. The LLZTO-based SEI film can not only guide Li to uniformly deposit at the interface but also accelerate the electrochemical reaction kinetics due to its high Li + conductivity. In particular, the high Young's modulus of the LLZTO-based SEI will regulate e - distribution in the continuous Li plating/stripping process and achieve uniform deposition of Li. As a consequence, the Li anode with LLZTO-based SEI (Li@LLZTO) enables symmetric cells to demonstrate a stable overpotential of 25 mV for 600 h at a current density of 1 mA cm -2 for 1 mA h cm -2 . The Li@LLZTO||LFP (LiFePO 4 ) full cell exhibits a capacity of 106 mA h g -1 after 800 cycles at 5 C with retention as high as 90%. Our strategy here suggests that the artificial SEI with high Young's modulus effectively inhibits the formation of Li dendrites and provides some guidance for the design of higher performance Li metal batteries.

Converting CO 2 into valuable chemicals via sustainable energy sources is indispensable for human development. Photothermal catalysis combines the high selectivity of photocatalysis and the high yield of thermal catalysis, which is promising for CO 2 reduction. However, the present photothermal catalysts suffer from low activity due to their poor light absorption ability and fast recombination of photogenerated electrons and holes. Here, a TiO 2 @Bi 2 WO 6 heterojunction photocatalyst featuring a hierarchical hollow structure was prepared by an in situ growth method. The visible light absorption and photothermal effect of the TiO 2 @Bi 2 WO 6 photocatalyst is promoted by a hierarchical hollow structure, while the recombination phenomenon is significantly mitigated due to the construction of the heterojunction interface and the existence of excited Bi (3- x )+ sites. Such a catalyst exhibits excellent photothermal performance with a CO yield of 43.7 μmol h -1 g -1 , which is 15 and 4.7 times higher than that of pure Bi 2 WO 6 and that of physically mixed TiO 2 /Bi 2 WO 6 , respectively. An in situ study shows that the pathway for the transformation of CO 2 into CO over our TiO 2 @Bi 2 WO 6 proceeds via two important intermediates, including COO - and COOH - . Our work provides a new idea of excited states for the design and synthesis of highly efficient photothermal catalysts for CO 2 conversion.

Silicon (Si) is considered as the most likely choice for the high-capacity lithium-ion batteries owing to its ultrahigh theoretical capacity (4200 mA h g -1 ) being over 10 times than that of traditional graphite anode materials (372 mA h g -1 ). However, its widespread application is limited by problems such as a large volume expansion and low electrical conductivity. Herein, we design a hollow nitrogen-doped carbon-coated silicon (Si@Co-HNC) composite in a water-based system via a synergistic protecting-etching strategy of tannic acid. The prepared Si@Co-HNC composite can effectively mitigate the volume change of silicon and improve the electrical conductivity. Moreover, the abundant voids inside the carbon layer and the porous carbon layer accelerate the transport of electrons and lithium ions, resulting in excellent electrochemical performance. The reversible discharge capacity of 1205 mA h g -1 can be retained after 120 cycles at a current density of 0.5 A g -1 . In particular, the discharge capacity can be maintained at 1066 mA h g -1 after 300 cycles at a high current density of 1 A g -1 . This study provides a new strategy for the design of Si-based anode materials with excellent electrical conductivity and structural stability.

The severe shuttling behavior in the discharging-charging process largely hampers the commercialization of lithium-sulfur (Li-S) batteries. Herein, we design a bifunctional separator with an ultra-lightweight MnO 2 coating to establish strong chemical adsorption barriers for shuttling effect alleviation. The double-sided polar MnO 2 layers not only trap the lithium polysulfides through extraordinary chemical bonding but also ensure the uniform Li + flux on the lithium anode and inhibit the side reaction, resulting in homogeneous plating and stripping to avoid corrosion of the Li anode. Consequently, the assembled Li-S battery with the MnO 2 -modified separator retains a capacity of 665 mA h g -1 at 1 C after 1000 cycles at the areal sulfur loading of 2.5 mg cm -2 , corresponding to only 0.028% capacity decay per cycle. Notably, the areal loading of ultra-lightweight MnO 2 coating is as low as 0.007 mg cm -2 , facilitating the achievement of a high energy density of Li-S batteries. This work reveals that the polar metal oxide-modified separator can effectively inhibit the shuttle effect and protect the Li anode for high-performance Li-S batteries.

Besides improving charge transfer, there are two key factors, such as increasing active sites and promoting water dissociation, to be deeply investigated to realize high-performance MoS 2 -based electrocatalysts in alkaline hydrogen evolution reaction (HER). Herein, we have demonstrated the synergistic engineering to realize rich unsaturated sulfur atoms and activated O-H bonds toward the water for Ni-doped MoS 2 /CoS 2 hierarchical structures by an approach to Ni doping coupled with in situ sulfurizing for excellent alkaline HER. In this work, the Ni-doped atoms are evolved into Ni(OH) 2 during alkaline HER. Interestingly, the extra unsaturated sulfur atoms will be modulated into MoS 2 nanosheets by breaking Ni-S bonds during the formation of Ni(OH) 2 . On the other hand, the higher the mass of the Ni precursor ( m Ni ) for the fabrication of our samples, the more Ni(OH) 2 is evolved, indicating a stronger ability for water dissociation of our samples during alkaline HER. Our results further reveal that regulating m Ni is crucial to the HER activity of the as-synthesized samples. By regulating m Ni to 0.300 g, a balance between increasing active sites and promoting water dissociation is achieved for the Ni-doped MoS 2 /CoS 2 samples to boost alkaline HER. Consequently, the optimal samples present the highest HER activity among all counterparts, accompanied by reliable long-term stability. This work will promise important applications in the field of electrocatalytic hydrogen evolution in alkaline environments.

Molecular catalysis for selective CO 2 electroreduction into CO can be achieved with a variety of metal complexes. Their immobilization on cathodes is required for their practical implementation in electrolytic cells and can benefit from the advantages of a solid material such as easy separation of products and catalysts, efficient electron transfer to the catalyst, and high stability. However, this approach remains insufficiently explored up to now. Here, using an appropriate and original modification of the cyclam ligand, we report a novel [Ni(cyclam)] 2+ complex which can be immobilized on carbon nanotubes. This material, once deposited on a gas diffusion layer, provides a novel electrode which is remarkably selective for CO 2 electroreduction to CO, not only in organic solvents but also, more remarkably, in water, with faradic efficiencies for CO larger than 90% and current densities of 5-10 mA cm -2 during controlled potential electrolysis in H-cells.

Metal-organic frameworks (MOFs) have received great attention in recent years as potential adsorbents for CO 2 capture due to their unique properties. However, the high cost and their tedious synthesis procedures impede their industrial application. A series of new CO 2 -philic oxalamide-functionalized MOFs have been solvothermally synthesized: {[Zn 3 (μ 8 -OATA) 1.5 (H 2 O) 2 (DMF)]·5/2H 2 O·5DMF} n (Zn-OATA), {[NH 2 (CH 3 ) 2 ][Cd(μ 4 -HOATA)]·H 2 O·DMF} n (Cd-OATA), and {[Co 2 (μ 7 -OATA)(H 2 O)(DMF) 2 ]·2H 2 O·3DMF} n (Co-OATA) (H 4 OATA = N , N '-bis(3,5-dicarboxyphenyl)oxalamide). In Zn-OATA, the [Zn 2 (CO 2 ) 4 ] SBUs are connected by OATA 4- ligands into a 3D framework with 4-connected NbO topology. In Cd-OATA, two anionic frameworks with a dia topology interpenetrated each other to form a porous structure. In Co-OATA, [Co 2 (CO 2 ) 4 ] units are linked by four OATA 4- to form a 3D framework with binodal 4,4-connected 4 2 ·8 4 PtS-type topology. Very interestingly, Cu-OATA can be prepared from Zn-OATA by a facile metal ions exchange procedure without damaging the structure while the CO 2 adsorption ability can be largely enhanced when Zn(II) metal ions are exchanged to Cu(II). These new MOFs possess channels decorated by the CO 2 -philic oxalamide groups and accessible open metal sites, suitable for highly selective CO 2 adsorption. Cu-OATA exhibits a significant CO 2 adsorption capacity of 25.35 wt % (138.85 cm 3 /g) at 273 K and 9.84 wt % (50.08 cm 3 /g) at 298 K under 1 bar with isosteric heat of adsorption ( Q st ) of about 25 kJ/mol. Cu-OATA presents a very high selectivity of 5.5 for CO 2 /CH 4 and 43.8 for CO 2 /N 2 separation at 0.1 bar, 298 K. Cd-OATA exhibits a CO 2 sorption isotherm with hysteresis that can be originated from structural rearrangements. Cd-OATA adsorbs CO 2 up to 11.90 wt % (60.58 cm 3 /g) at 273 K and 2.26 wt % (11.40 cm 3 /g) at 298 K under 1 bar. Moreover, these new MOFs exhibit high stability in various organic solvents, water, and acidic or basic media. The present work opens a new opportunity in the development of improved and cost-effective MOF adsorbents for highly efficient CO 2 capture.

A highly efficient photoenergy conversion is strongly dependent on the cumulative cascade efficiency of the photogenerated carriers. Spatial heterojunctions are critical to directed charge transfer and, thus, attractive but still a challenge. Here, a spatially ternary titanium-defected TiO 2 @carbon quantum dots@reduced graphene oxide (denoted as V Ti @CQDs@rGO) in one system is shown to demonstrate a cascade effect of charges and significant performances regarding the photocurrent, the apparent quantum yield, and photocatalysis such as H 2 production from water splitting and CO 2 reduction. A key aspect in the construction is the technologically irrational junction of Ti-vacancies and nanocarbons for the spatially inside-out heterojunction. The new "spatial heterojunctions" concept, characteristics, mechanism, and extension are proposed at an atomic-/nanoscale to clarify the generation of rational heterojunctions as well as the cascade electron transfer.

Cell surface engineering is an emerging technology to encapsulate cells in order to enhance their functions. However, methods for reversible encapsulation of cells with abiotic functionalities are rare. Herein, we describe a phenylboronic acid based click reaction for encapsulation of single yeast cells using mesoporous silica nanoparticles (MSNs). This encapsulation does not impact natural growth of the cells and leads to a significant enhancement of cell survival in a variety of hostile environments. Owing to the glucose-responsiveness of the boronate ester bond between cell surface polysaccharides and B(OH) 2 -grafted MSNs, encapsulation was reversible by addition or removal of glucose. This effort offers living cells effective protection under harsh conditions and enables reversible assembling-detaching of abiotic functions.

The development of lithium-ion batteries using transition metal oxides has recently become more attractive, due to their higher specific capacities, better rate capability, and high energy densities. Herein, the in situ growth of advanced mesoporous CuO/O-doped g-C 3 N 4 nanospheres is carried out in a two step hydrothermal process at 180 °C and annealing in air at 300 °C. When used as an anode material, the CuO/O-doped g-C 3 N 4 nanospheres achieve a high reversible discharge specific capacity of 738 mAhg -1 and a capacity retention of ∼75.3% after 100 cycles at a current density 100 mAg -1 compared with the pure CuO (412 mAhg -1 , 47%) and O-doped g-C 3 N 4 (66 mAhg -1 , 53%). Even at high current density 1 Ag -1 , they exhibit a reversible discharge specific capacity of 503 mAhg -1 and capacity retention ∼80% over 500 cycles. The excellent electrochemical performance of the CuO/O-doped g-C 3 N 4 nanocomposite is attributed to the following factors: (I) the in situ growing CuO/O-doped g-C 3 N 4 avoids CuO nanoparticle aggregation, leading to the improved lithium ion transfer and electrolyte penetration inside the CuO/O-doped g-C 3 N 4 anode, thus promoting the utilization of CuO; (II) the porous structure provides efficient space for Li + transfer during the insertion/extraction process to avoid large volume changes; (III) the O-doping g-C 3 N 4 decreases its band gap, ensuring the increased electrical conductivity of CuO/O-doped g-C 3 N 4 ; and (IV) the strong interaction between CuO and O-doped g-C 3 N 4 ensures the stability of the structure during cycling.

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.

The metal-organic framework (MOF) MIL-101Cr was readily encapsulated by a very thin shell (around 30 nm) of hydrophobic mesoporous silica, which replicates the irregular shape of the MOF nanocrystals. Such a silica shell facilitates the diffusion of hydrophobic reactants with enhancement of the catalytic activity of the MOF and significantly improved catalytic stability of the MOF in the oxidation of indene.

Vanadium oxides are promising anode materials for lithium-ion batteries (LIBs) due to their high capacity, good safety, and low cost. However, their practical application has been deferred by the poor rate capability and cycling stability. In this work, we report the designed synthesis of porous V 2 O 3 /VO 2 @carbon heterostructure electrode for high-performance LIBs. The synergic effects of porous nanostructures, phase hybridization with self-building electric field at heterointerface, and conductive carbon implantation effectively enhance the electronic/ionic conduction and buffer the volume variation in the composite material. Electrochemical tests reveal that the composite electrode exhibits high Li-ion storage capacities of 503 and 453 mAh/g at 100 and 500 mA/g, as well as good cycling stability with a retained capacity of 569 mAh/g over 105 cycles at 100 mA/g. In-depth kinetics analysis discloses that pseudocapacitive Li-ion storage process dominates in the composite electrode, which is probably enabled by efficient coupling of the heterostructure components. The strategy of in situ carbon implantation and phase hybridization presented herein may be extended to other electrode materials for rechargeable batteries with superior electrochemical properties.

Phase-junctions between a cocatalyst and its semiconductor host are quite effective to enhance the photocatalytic activity and are widely studied, while reports on the phase-juncted cocatalyst are still rare. In this work, we report the deposition of the Pt/PtO phase-juncted nanodots as cocatalyst via NaOH modification of an interconnected meso-macroporous TiO 2 network with high surface area and inner-particle mesopores to enhance the performance of photocatalytic H 2 production. Our results show that NaOH modification can largely influence Pt/PtO phase-juncted nanodot formation and dispersity. Compared to the TiO 2 nanoparticles, the hierarchically meso-macroporous TiO 2 network containing 0.18 wt % Pt/PtO phase-juncted cocatalyst demonstrates a highest photocatalytic H 2 rate of 13 mmol g -1 h -1 under simulated solar light, and possesses a stable cycling activity without obvious decrease after five cycles. Such high H 2 production performance can be attributed to both the phase-juncted Pt/PtO providing more active sites while PtO suppresses the undesirable hydrogen back reaction, and the special hierarchically porous TiO 2 network with inner-particle mesopores presenting short diffusion path lengths for photogenerated electrons and enhanced light harvesting efficiency. This work suggests that Pt/PtO phase-juncted cocatalyst on hierarchically porous TiO 2 nanostructures is a promising strategy for advanced photocatalytic H 2 production.

TiO 2 is a promising and safe anode material for lithium ion batteries (LIBs). However, its practical application has been plagued by its poor rate capability and cycling properties. Herein, we successfully demonstrate a novel structured TiO 2 anode with excellent rate capability and ultralong cycle life. The TiO 2 material reported here shows a walnut-like porous core/shell structure with hybridized anatase/amorphous phases. The effective synergy of the unique walnut-like porous core/shell structure, the phase hybridization with nanoscale coherent heterointerfaces, and the presence of minor carbon species endows the TiO 2 material with superior lithium storage properties in terms of high capacity (∼177 mA h g -1 at 1 C, 1 C = 170 mA g -1 ), good rate capability (62 mA h g -1 at 100 C), and excellent cycling stability (∼83 mA h g -1 was retained over 10 000 cycles at 10 C with a capacity decay of 0.002% per cycle).

Hybrid beads with entrapped microalgae Chlamydomonas reinhardtii were synthesized for the sustainable production of high value metabolites via photosynthesis. Encapsulating the microalgae requires an exquisite control of material properties, which has been achieved by modifying the composition (alginate, polycation, and silica). A coating of PDADMAC precluded cell leakage as indicated by the OD750 value of the culture medium, and the homogeneous distribution of silica prevented bead shrinkage from the strong electronic force of PDADMAC, resulting in a robust and biocompatible matrix for the cells. Besides fabricating suitable porous beads for the diffusion of expected metabolites, the permeability can be controlled to a certain degree by applying different molecular weights of PDADMAC. The hybrid alginate+silica/CaCl2+PDADMAC beads possessed sufficient mechanical rigidity to sheer force under constant stirring and good chemical stability to chelating agents such as sodium citrate. Moreover, the encapsulated cells exhibited excellent long-term viability and cellular functionality, which retained about 81.5% of the original value after a 120 day encapsulation as observed by microscopy and oximetry measurement. This study is not only significant for understanding the critical role of polycations and silica involved in the synthesis of hybrid beads but also important for real-scale bioengineering applications.

Three-dimensional (3D) macro-mesoporous structures demonstrate effective performance for gas sensing. In this work, we have designed and successfully prepared aperture-controllable three-dimensional interconnected macro-mesoporous ZnO (3D-IMM-ZnO) nanostructures by template-based layer-by-layer filtration deposition. XRD, SEM, and TEM have been used to characterize the obtained hexagonal wurzite 3D-IMM-ZnO nanostructures. Owing to its special 3D interconnected hierarchically porous structure, the 3D-IMM-ZnO nanostructures exhibit excellent gas sensing performances toward acetone and methanol. The 3D-IMM-ZnO nanostructure with the largest macropore demonstrates the best gas sensitivity owing to its largest cavity providing enough space for gas diffusion. On the basis of the results and analyses, we propose that the synergistic effect of electron liberation and electron density of acetone and the special structure make the 3D-IMM-ZnO nanostructures demonstrate better gas sensing properties than many other porous ZnO nanostructures and preferred selectivity to acetone.

When three-dimensionally ordered macroporous (3DOM) materials are synthesized in polymeric colloidal crystal templates using a Pechini-type approach, polymerization-induced phase separation (PIPS) can occur. Depending on the reaction conditions, the porous products have a variety of morphologies, including an extended inverse opal structure, bicontinuous networks of 3DOM materials interrupted by extended voids, uniform 3DOM microspheres, sheet structures of templated macroporous oxides, and hollow particles obtained by structural disassembly. In this study, the mechanism underpinning morphology control of 3DOM metal oxides through PIPS is elucidated for Ce(0.5)Mg(0.5)O(1.5) and CeO(2) systems. The mechanistic information is then applied to synthesize target morphologies for Mn(3)O(4) and Fe(2)O(3)/Fe(3)O(4) systems, demonstrating the more general nature of the synthetic approach for aqueous metal precursors that can be complexed with citric acid. The effects of reactant balance, complexation behavior, processing temperature, and template sphere size are related directly to the microstructures obtained. The predominant controlling factor of microstructural evolution in PIPS Pechini precursors is found to be the degree of polymerization of the polyester, which can be controlled through tailoring the reagent imbalance. 3DOM microspheres produced by the method are between 0.5 and 3 μm in size, with polydispersities below 25%.

A mononuclear iron(II) neutral complex (1) is screened for sensing abilities for a wide spectrum of chemicals and to evaluate the response function toward physical perturbation like temperature and mechanical stress. Interestingly, 1 precisely detects methanol among an alcohol series. The sensing process is visually detectable, fatigue-resistant, highly selective, and reusable. The sensing ability is attributed to molecular sieving and subsequent spin-state change of iron centers, after a crystal-to-crystal transformation.

Hierarchically structured spongy meso-macroporous aluminosilicates with high tetrahedral aluminum content were synthesized from a mixture of single molecular alkoxide precursor, (sec-BuO)2-Al-O-Si(OEt)3, already containing Si-O-Al bonds, and a silica coreactant, tetramethoxysilane (TMOS). The spontaneous byproduct templated macroporous structure formation has been directly visualized using in situ high-resolution optical microscopy (OM), allowing the crucial observation of a microbubble dispersion which is directly correlated to the macrostructure observed by electronic microscopies (SEM and TEM). This discovery leads to a comparative study with meso-macroporous pure metal oxide and to a proposal of the formation mechanism of meso-macroporous aluminosilicates with 3D interconnectivity. The aluminosilicate phase/microbubbles emulsion is produced by a phase separation process occurring between the aluminosilicate nanoparticles and the liquid hydrolysis-condensation reaction byproducts (water, methanol, ethanol, and butanol). The use of alkoxysilane improves the heterocondensation rates between the highly reactive aluminum alkoxide part of the single precursor and added silica species but, above all, leads to the spontaneous generation of an unusual meso-macroporosity in alkaline media. The particles obtained at pH = 13.0 featured regular micrometer-sized macrospheres separated by very thin mesoporous walls and connected by submicrometric openings, providing a 3D interconnectivity. The slight increase in pH value to 13.5 induced significant modifications in morphology and textural properties due to the slower gelification process of the aluminosilicate phase, resulting in the formation of an aluminosilicate material constituted of 1-2 µm large independent hollow mesoporous spheres.

A novel yet facile synthesis pathway has been developed for the design of hierarchically structured macro-mesoporous aluminosilicates with high aluminum content at tetrahedral sites using a single molecular bifunctional alkoxide (sec-BuO)(2)-Al-O-Si(OEt)(3) precursor. The use of carboxylate ligands and a highly alkaline media slow down the polymerization rate of the aluminum alkoxide functionality, thus permitting the preservation of the intrinsic Al-O-Si linkage. The hierarchically structured porous aluminosilicate materials present an unprecedented low Si/Al ratio close to 1. Heat treatment applied to the synthesized material seems to favor the incorporation of aluminum into tetrahedral position (intraframework aluminum species). The macro-mesoporosity was spontaneously generated, without the use of any external templating agent, by the hydrodynamic flow of the solvents released during the rapid hydrolysis and condensation processes of this double alkoxide. This method results in materials with an open array of interconnected macrochannels. The synthesized aluminosilicate materials with tailorable macro-mesoporous hierarchy and very high Al content at tetrahedral position hold huge promise in various applications as catalysts, catalysts supports, or adsorbents.

The encapsulation of living plant cells into materials could offer the possibility to develop new green biochemical technologies. With the view to designing new functional materials, the physiological activity and cellular response of entrapped cells within different silica-based matrices have been assessed. A fine-tuning of the surface chemistry of the matrix has been achieved by the in situ copolymerization of an aqueous silica precursor and a biocompatible trifunctional silane bearing covalently bound neutral sugars. This method allows a facile control of chemical and physical interactions between the entrapped plant cells and the scaffold. The results show that the cell-matrix interaction has to be carefully controlled in order to avoid the mineralization of the cell wall which typically reduces the bioavailability of nutrients. Under appropriate conditions, the introduction of a trifunctional silane (ca. 10%) during the preparation of hybrid gels has shown to prolong the biological activity as well as the cellular viability of plant cells. The relations of cell behavior with some other key factors such as the porosity and the contraction of the matrix are also discussed.

We report a new open-framework silicogermanate SU-61 containing 26-ring channels with a low framework density. It can be seen as a crystalline analogue to the mesoporous silica MCM-41. The structure is built from the assembly of (Ge,Si)10(O,OH)28 clusters. It is the first time that silicon has been successfully introduced in the Ge10 cluster in significant amounts ( approximately 21% of the tetrahedral sites). Five- and six-coordinated Ge10 clusters have previously been observed in other germanate compounds leading to either dense or open structures. In SU-61, the seven-coordinated clusters fall onto yet another underlying net, the osf net. SU-61, along with other Ge10 based frameworks, shows the versatility of the germanate system to adopt defined topologies playing on the connectivity of the clusters following the principles of net decoration and scale chemistry.

First hierarchical titanium phosphate (TiPO) materials with multiple porosities of different lengths (meso-macroporous and meso-macro-macroporous) were synthesized by the self-formation process. The further tuning of the porous hierarchy by using the poly(ethylene oxide) surfactant technique was demonstrated. The macroporous structure (50-160 nm in size) of TiPO with mesoporous walls could be self-formed in the absence of any templatable agents, including surfactant molecules. On the basis of spontaneous structurization, the addition of a small quantity of nonionic poly(ethylene oxide) surfactant (e.g., 5%) led to an improvement in macroporosity in abundance and in regularity with a slight enlargement in macropore sizes to 80-250 nm. Interestingly, a secondary, larger macropore system with parallel channels 500-1000 nm in size was generated when the synthesis was performed with moderately increasing the content of surfactant (10%), giving rise to an unprecedented trimodal meso-macro-macroporous structure. A uniform three-dimensional co-continuous macroporous structure with accessible wormhole-like mesoporous walls was synthesized by using the higher content of surfactants. This is a direct demonstration of tailoring the porous hierarchy of different lengths integrated in one solid body by fine-tuning the self-formation process and the participation of surfactant. The synthesized hierarchical titanium phosphates possess interesting optical and acidic properties, which should be significant for large application potential from catalysis and separation to electrochromic devices, fuel cells, and bioactive materials.

The comparison plot obtained from the nitrogen adsorption data has a similar shape to that of the curve of accumulating pore volume of a solid. The intrinsic nature of this relation is discussed. It is known that the derivatives of the accumulating pore volume with respect to the pore size are the pore size distribution (PSD) of the solid. Thus, the tangent curve of the comparison plot can display, at least qualitatively, the PSD of a solid, over a wide range of pore sizes (from approximately 1 to 50 nm) because the comparison plot is applicable to both micropores and mesopores. Quantitative pore structure information can be derived from the comparison plots by establishing a relationship between the t value and the pore size from the samples with uniform pore structure and known pore sizes, such as MCM-41 and alumina pillared clay samples. A calculation procedure to derive quantitative PSD from the comparison plots is suggested, giving reasonable results. This study proposes concise and reliable methods based on the comparison plots to derive information on pore structure in porous solids.