Investigation of the Photoluminescence and Nonlinear Optical Properties of Ce₂O₃-TiO₂ Nanocomposites.

This paper reports the photoluminescence and nonlinear optical (NLO) properties of Ce₂O₃-TiO₂ nanocomposites synthesized via sol-gel process with different concentrations of cerium. The physical characterization studies by means of XRD indicated for the successful incorporation of Ce into the lattice of TiO₂, while the UV-visible spectra for an absorption edge shift of TiO₂ to the higher wavelength side following the Ce addition, and FESEM analysis for the morphology and particles sizes of the synthesized materials. On testing of the photoluminescence properties recorded through time-resolved fluorescence (TCSPC) technique, a decrease in the intensity of TiO₂ with that of increased Ce concentration was observed and is due to an escalation in the number of oxygen vacancies.

Design of P-Doped Mesoporous Carbon Nitrides as High-Performance Anode Materials for Li-Ion Battery.

Herein, we demonstrate a simple and unique strategy for the preparation of P-doped into the substructure of mesoporous carbon nitride materials (P-MCN-1) with ordered porous structures as a high-energy and high-power Li-ion battery (LIB) anode. The P-MCN-1 as an anode in LIB delivers a high reversible discharge capacity of 963 mAh g even after 1000 cycles at a current density of 1 A g, which is much higher than that of other counterparts comprising -triazine (CHN, g-CN), pristine MCN-1, and B-containing MCN-1 (B-MCN-1) subunits or carbon allotropes like CNT and graphene (rGO) materials. The P-MCN-1 electrode also exhibits exceptional rate capability even at high current densities of 5, 10, and 20 A g delivering 685, 539, and 274 mAh g, respectively, after 2500 cycles.

Electrochemical sensor and biosensor platforms based on advanced nanomaterials for biological and biomedical applications.

Introduction of novel functional nanomaterials and analytical technologies signify a foremost possibility for the advance of electrochemical sensor and biosensor platforms/devices for a broad series of applications including biological, biomedical, biotechnological, clinical and medical diagnostics, environmental and health monitoring, and food industries. The design of sensitive and selective electrochemical biological sensor platforms are accomplished conceivably by offering new surface modifications, microfabrication techniques, and diverse nanomaterials with unique properties for in vivo and in vitro medical analysis via relating a sensibly planned electrode/solution interface. The advantageous attributes such as low-cost, miniaturization, energy efficient, easy fabrication, online monitoring, and the simultaneous sensing capability are the driving force towards continued growth of electrochemical biosensing platforms, which have fascinated the interdisciplinary research arenas spanning chemistry, material science, biological science, and medical industries.

Self-degrading niosomes for encapsulation of hydrophilic and hydrophobic drugs: An efficient carrier for cancer multi-drug delivery.

In this study, we have examined the encapsulation and release of hydrophilic and hydrophobic drugs in self-degrading niosomes as a unique method for anticancer therapy. Niosomes were prepared by amphiphilic self-assembly of Tween 80 and cholesterol through film hydration method. Encapsulation studies with two active molecules curcumin and doxorubicin hydrochloride (Dox) showed that curcumin is supposed to accumulate in the shell whereas Dox accumulates in the inner aqueous core of the niosome.

Mesoporous BaTiO₃@SBA-15 derived via solid state reaction and its excellent adsorption efficiency for the removal of hexavalent chromium from water.

We report the synthesis of a barium-titanate/mesoporous silica nanocomposite material BaTiO3@SBA-15 via aerosol assisted solid state reaction using SBA-15 as a hard template. Hexavalent chromium is one of the most harmful contaminants of industrial waste-water. We have used BaTiO3@SBA-15 nanocomposite as an adsorbent for the removal of chromium(vi)-contaminated water and it showed an adsorption capacity of 98.

The dual role of micelles as templates and reducing agents for the fabrication of catalytically active hollow silver nanospheres.

We report a simple and efficient protocol for fabrication of colloidal hollow silver nanospheres of size less than 30 nm using an ABC triblock copolymer poly(styrene-b-vinyl-2-pyridine-b-ethylene oxide) in the absence of any reducing agents. The colloidal silver hollow nanoparticles serve as an efficient heterogeneous catalyst for Baeyer-Villiger oxidation of ketones to the corresponding lactones in the presence of anhydrous tert-butylhydroperoxide under liquid-phase conditions.

Fabrication of Al-beta/silicalite-1 hydrophilic-hydrophobic zeolite membranes.

Hydrophobic-hydrophilic composite membranes containing silicalite-1 and Al-beta zeolites are prepared on the outer surface of the porous alpha-alumina tube for the first time. The hydrophilic layer with aluminum serves as an active catalytic domain, whereas the hydrophobic layer containing silicalite-1 with medium pore-size is expected to assist in separating the reaction products based on their hydrophobicity as well as shape-selectivity. The continuous defect-free composite membranes are fabricated by two-step synthesis approach by initial deposition of Al-beta crystals on the outer surface of porous alumina tube followed by coating of silicalite-1 crystals over the Al-beta layer in the second step under hydrothermal conditions.

Core-shell-corona polymeric micelles as a versatile template for synthesis of inorganic hollow nanospheres.

Hollow, inorganic nanoscale capsules have many applications, from the delivery of encapsulated products for cosmetic and medicinal purposes to use as lightweight composite materials. Early methods for producing inorganic hollow nanospheres using hard templates suffered from low product yield and shell weakness upon template removal. In the past decade, researchers have turned to amphiphilic copolymers to synthesize hollow nanostructures and ordered mesoporous materials.

Synthesis of mesoporous hollow silica nanospheres using polymeric micelles as template and their application as a drug-delivery carrier.

Mesoporous hollow silica nanospheres with uniform particle sizes of 31-33 nm have been successfully synthesized by cocondensation of tetramethoxysilane (TMOS) and alkyltrimethoxysilanes [RSi(OR)3], where the latter also acts as a porogen. ABC triblock copolymer micelles of poly(styrene-b-2-vinyl pyridine-b-ethylene oxide) (PS-PVP-PEO) with a core-shell-corona architecture have been employed as a soft template at pH 4. The cationic shell block with 2-vinyl pyridine groups facilitates the condensation of silica precursors under the sol-gel reaction conditions.

Novel and mild synthetic strategy for the sulfonic Acid functionalization in periodic mesoporous ethenylene-silica.

A new postsynthetic method has been developed for sulfonic acid functionalization of hybrid periodic mesoporous organosilica (PMO) materials containing carbon-carbon double bonds (-C═C-) located in mesoporous wall structures. Hexagonal mesoporous ethenylene-silicas (HME) with different pore sizes were synthesized by using P123, Brij76, and Brij56 surfactants and investigated for postsynthetic functionalization. The present functionalization strategy involves epoxidation of double bonds at -5 °C followed by conversion of the resulting epoxide with bisulfite ions at 65 °C and involves neither the use of well-known mercaptol/H2O2 nor harsh concentrated H2SO4 reagents during the course of -C═C- functionalization.

3D hexagonal mesoporous silica and its organic functionalization for high CO2 uptake.

Highly ordered 3D-hexagonal mesoporous silica HMS-3 and its vinyl- and 3-chloropropyl-functionalized analogues HMS-4 and -5, respectively, are synthesized under strongly alkaline conditions at 277 K. Tetraethyl orthosilicate, vinyltrimethoxysilane, and 3-chloropropyltrimethoxysilane are used as silica sources, and cetyltrimethylammonium bromide as the structure-directing agent. The 3D-hexagonal pore structures of HMS-3, 4-, and -5 were confirmed by powder XRD and high-resolution TEM studies.

La2O3 hollow nanospheres for high performance lithium-ion rechargeable batteries.

An efficient and simple protocol for synthesis of novel La(2)O(3) hollow nanospheres of size about 30 ± 2 nm using polymeric micelles is reported. The La(2)O(3) hollow nanospheres exhibit high charge capacity and cycling performance in lithium-ion rechargeable batteries (LIBs), which was scrutinized for the first time among the rare-earth oxides.

Novel LaBO3 hollow nanospheres of size 34±2 nm templated by polymeric micelles.

Novel lanthanum borate (LaBO(3)) hollow nanospheres of size 34±2 nm have been reported for the first time by soft-template self-assembly process. Poly(styrene-b-acrylic acid-b-ethylene oxide) (PS-PAA-PEO) micelle with core-shell-corona architecture serves as an efficient soft template for fabrication of LaBO(3) hollow particles using sodium borohydride (NaBH(4)) and LaCl(3)⋅7H(2)O as the precursors. In this template, the PS block (core) acts as a template of the void space of hollow particle, the anionic PAA block (shell) serves as reaction field for metal ion interactions, and the PEO block (corona) stabilizes the polymer/lanthana composite particles.

Periodic organosilica hollow nanospheres as anode materials for lithium ion rechargeable batteries.

Polymeric micelles with core-shell-corona architecture have been found to be the efficient colloidal templates for synthesis of periodic organosilica hollow nanospheres over a broad pH range from acidic to alkaline media. In alkaline medium, poly (styrene-b-[3-(methacryloylamino)propyl] trimethylammonium chloride-b-ethylene oxide) (PS-PMAPTAC-PEO) micelles yield benzene-silica hollow nanospheres with molecular scale periodicity of benzene groups in the shell domain of hollow particles. Whereas, an acidic medium (pH 4) produces diverse hollow particles with benzene, ethylene, and a mixture of ethylene and dipropyldisulfide bridging functionalities using poly(styrene-b-2-vinyl pyridine-b-ethylene oxide) (PS-PVP-PEO) micelles.

Novel synthesis of bifunctional catalysts with different microenvironments.

Acid-base bifunctional activity governed by -NH(2) group's microenvironment is evident from two different catalysts scrutinized by interchanging the location of -SO(3)H/NH(2) groups on periodic mesoporous ethylenesilica. The hydrophobic local environment plays a significant role in one-pot deacetalization/nitroaldol condensation.

Designing the synthesis of catalytically active Ti-β by using various new templates in the presence of fluoride anion.

Crystallization of large-pore Ti-β by using a variety of diquaternary ammonium derivatives of dibromoalkane and amines such as triethylamine, 1,4-diazabicyclo[2,2,2]octane (DABCO), and quinuclidine as structure-directing agents (SDA) is described. The size of hydrophobic bridging alkyl-chain length of the template [R(3)N(+)-(CH(2))(x)-N(+)R(3)](OH(-))(2) directs the final crystalline product: Ti-β, Ti-ZSM-12, Ti-nonasil or Ti-ZSM-5, as x gradually changes from 6 to 1, in the fluoride medium under hydrothermal conditions. A dense phase such as Ti-nonasil (clathrasil type) is crystallized as the size of hydrophobic bridging alkyl-chain length decreases.

Novel titania hollow nanospheres of size 28 ± 1 nm using soft-templates and their application for lithium-ion rechargeable batteries.

We report a novel protocol to prepare titania hollow nanospheres of size about 28 ± 1 nm with micelles of asymmetric triblock copolymers. The hollow particles exhibit unique electrochemical properties in lithium ion rechargeable batteries such as high capacity, very low irreversible capacity loss, and high cycling performance.

Micelles of poly(styrene-b-2-vinylpyridine-b-ethylene oxide) with blended polystyrene core and their application to the synthesis of hollow silica nanospheres.

Core-shell-corona (CSC) micelles of asymmetric triblock copolymer, poly(styrene-b-2-vinylpyridine-b-ethylene oxide) (PS-PVP-PEO), containing polystyrene homopolymer (homo-PS) in the core were successfully prepared in aqueous media. The influence of homo-PS contents over the formation of the micelles was investigated thoroughly by various techniques such as dynamic light scattering (DLS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and fluorescence spectroscopy. It was found that the size of the PS core of the micelle was increased by the addition of homo-PS as observed by DLS and TEM techniques.

Naked eye detection of cadmium using inorganic-organic hybrid mesoporous material.

A novel and low-cost optical sensor for the naked eye detection of Cd2+ in aqueous media based on mesoporous silica containing 4-(2-pyridylazo)resorcinol (PAR) as a probe molecule anchored by N-trimethoxysilylpropyl-N,N,N-trimethylammonium chloride (TMAC) was prepared. The effects of various factors such as pH, solvent volume, temperature, reaction time, amount of the material, and the presence of various ions were studied in order to optimize operating conditions. The detection was based on the color change of PAR from orange-yellow to purple as a result of complexation with Cd2+.

Optical sensor for the visual detection of mercury using mesoporous silica anchoring porphyrin moiety.

A low cost, solid optical sensor for the rapid detection of low concentrations of Hg2+ in aqueous media was prepared by the monolayer functionalization of mesoporous silica with 5,10,15,20-tetraphenylporphinetetrasulfonic acid (TPPS), anchored by N-trimethoxysilylpropyl-N,N,N-trimethylammonium chloride (TMAC). The detection is based on the color change of TPPS from orange to green as a result of the formation of a charge-transfer complex with Hg2+. The intensity of the charge-transfer band varies linearly with Hg2+ in the concentration range from zero to 2.