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Emulsion template-guided strategy has been used to produce porous architectures with exquisite structure, tailored morphology, and exclusive features for ubiquitous applications. Notwithstanding, the practical water remediation is often marred by their transport-limited behavior and fragility. To circumvent these conundrums, we prepared hierarchically porous poly(acrylic acid)-alumina nanocomposite beads by solidifying the droplets of emulsions jointly stabilized by the organic surfactants and alumina nanoparticles. By virtue of their positive charge, the alumina nanoparticles got entrapped within the poly(acrylic acid) scaffolds that excluded the risk of secondary contamination typically observed with conventional nanocomposites. Being amenable to surface modification, the carboxyl moieties of the beaded polymer were further exploited to covalently tether branched polyethylenimine throughout the exterior and interior surface of the porous matrix via a grafting-to approach. The macropores expedite an active fluid flow and easier adsorbate transport throughout the functionalized nanocomposites whose overall higher density of positive charge over a certain pH range electrostatically attracts and effectively adsorbs the negatively charged Cr(VI) complexes and anionic congo red ions/molecules from water. This proof-of-concept synthetic approach and postsynthetic modification offer an improved mechanical robustness to these macrosized multifunctional nanocomposite beads for their easier processing, thereby paving the way for the point-of-use water purification technology development.

Sunlight and water are among the most plentiful and sustainable resources of energy. Natural photosystem II in the plants uses these resources in ecofriendly manner for the production of atmospheric oxygen and energy. Inspired by this natural process, the development of artificial catalytic system to facilitate the solar-induced water splitting for the continuous production of hydrogen is the holy grail of the chemist and energy experts to meet the future energy demand at minimal environmental cost. Despite considerable research efforts dedicated to this area in the last decade, the development of highly efficient, stable and economic photocatalysts remain a challenging task for the large scale H2 production from water. Polyoxometalates (POMs)-based materials are emerging photo/photoelectrocatalysts in this quest owing to their multi-electron redox potential and fast reversible charge transfer properties, which are the essential requirements of photo-assisted water splitting catalysis. They are generally soluble in aqueous medium and thus their inherent catalytic/co-catalytic properties can be better exploited by incorporating/immobilizing them over suitable support materials. Therefore, exploration of discrete POM units over the support materials possessing high surface area, functionalizable architecture, flexible pore size and good light harvesting ability is an attractive area of research that has resulted in the generation of a strong library of heterocatalysts. The underlying support not only offers stability and recyclability attributes to the POM units but also provides decent dispersion, easy/maximum accessibility to the active sites, enhanced absorption capability, and synergistically enhances the activity by transfer of electrons and efficient charge/carriers separation by creating POM-support junctions. This mini-review emphasizes on the strategies for the incorporation of POMs on various porous supports like metal-organic frameworks (MOFs), covalent-organic frameworks (COFs), oxide-based semiconductors, carbonaceous materials, etc., and their applications as effective photo/photoelectrocatalysts for water splitting. In addition, the mechanistic study, comparative analysis and the future potential of these novel nanoscale materials is also highlighted. We believe that this review article will provide a new direction and scientific interest at the boundary of materials engineering, and solar-driven chemistry for the sustainable energy conversion/storage processes.

Aggregation-induced emission is a promising pathway to get high photoluminescence from metal nanocluster assemblies. The self-assembly of metal nanoclusters with regular morphologies can restrict the rotation and vibration modes of capping ligands, reduce nanoclusters' non-radiative decay, and finally result in an aggregation-induced strong emission. In this study, silver nanocluster self-assemblies stabilized by thiosalicylic acid (TSA) were prepared in water by equilibrium shifting, which exhibit nanofiber-like morphologies. The resulting silver nanocluster self-assemblies exhibit aggregation-induced emission in solid or aggregated state with a decent quantum yield i.e., 13.05%. The obtained silver nanocluster self-assemblies were thoroughly characterized by fluorescence spectroscopy, UV-visible absorption spectroscopy, X-ray photoelectron spectroscopy (XPS), matrix assisted laser desorption/ionization time-of-flight mass spectroscopy (MALDI-TOF), powder X-ray diffraction (PXRD) and high-resolution transmission electron microscopy (HRTEM). These silver nanocluster self-assemblies with high photoluminescence in aggregated state may have potential use in light emitting devices and bioapplications.

Oxygen evolution reaction (OER) is a bottleneck process in the water-splitting module for sustainable and clean energy production. Transition metal-based electrocatalysts can be effective as water-splitting catalytic materials because of their appropriate redox properties and natural abundance, but the slow kinetics because of strong adsorption and consequently slow desorption of intermediates on the active sites of catalysts severely hamper the dynamics of the released molecular oxygen and thus remains a formidable challenge. Herein, we report the development of structurally and surface-modified PA-Gd-Ni(OH)2Cl (partially alkylated gadolinium-doped nickel oxychloride) nanoclusters (NCs, size ≤ 3 nm) for enhanced and stable OER catalysis at low overpotential and high turnover frequency. The ameliorated catalytic performance was achieved by controlling the surface coverage of these NCs with hydrophobic ligands and through the incorporation of electronegative atoms to facilitate easy adsorption/desorption of intermediates on the catalyst surface, thus improving the liberation of O2. Such a surface and structural modification and uniform distribution at the nanoscale length are indeed worth considering to selectively tune the catalytic potential and further modernize the electrode materials for the challenging OER process.

Neisseria gonorrhoeae is among the most multidrug-resistant bacteria in circulation today, and new treatments are urgently needed. In this work, we demonstrate the ability of 5-mercapto-2-nitrobenzoic acid-coated silver nanoclusters (MNBA-AgNCs) to kill strains of Neisseria gonorrhoeae. Using an in vitro bactericidal assay, MNBA-AgNCs had been found to show significantly higher anti-gonococcal bioactivity than the antibiotics ceftriaxone and azithromycin and silver nitrate. These nanoclusters were effective against both planktonic bacteria and a gonococcal infection of human cell cultures in vitro. Treatment of human cells in vitro with MNBA-AgNCs did not induce significant release of lactate dehydrogenase, suggesting minimal cytotoxicity to eukaryotic cells. Our results suggest that MNBA-AgNCs hold great potential for topical treatment of localized gonorrhoeae.

The development of cost-effective and highly efficient electrocatalysts for oxygen evolution reaction (OER) is a grave challenge in water splitting catalysis for the clean and viable production of molecular hydrogen (H2). Herein, we report the fabrication of higher-dimensional thin film CuO nanostructures with controlled morphologies i.e., nanosheets, nanocubes, nanoflowers, and nanoleaves and their relative performance for water oxidation catalysis. Among these nanostructures, CuO nanoflowers exhibit high catalytic activity with an onset potential of 1.48 V and a Tafel slope of 84 mVdec−1 in 1 M KOH solution. Moreover, an overpotential of 270 mV and 400 mV is needed to attain a current density of 10 mAcm−2 and 100 mAcm−2 respectively with high Faradaic efficiency. More promisingly, the catalytic performance was found highly dependent upon the nanoscale features and subsequently the improved electrochemically active surface area (ECSA). Such morphology dependent OER performance and binder-free nature of catalyst may provide the high-speed track for electrons transport owing to the inherent catalyst-substrate electronic interconnection and thus making it more promising and high-performance electrocatalyst for OER.

It is necessary to study the possible interactions among various chemical surfaces and analytes before applying them to biological systems. We report the synthesis of carbon nanotubes-iron oxide (SPIONs-CNT) nanocomposite material by using lecithin stabilized superparamagnetic iron oxide nanoparticles (SPIONs) obtained by facile hydrothermal technique. Various characterizations of the obtained nanocomposite were carried out and electrochemical studies were performed further to study the interaction capabilities of the nanocomposite with anti-TB drug Rifampicin. Obtained results by cyclic voltammetric studies of SPIONs-CNT nanocomposite with limit of detection (LOD) of 1.178 μM showed the enhanced electrochemical sensitivity and selectivity of anti-tuberculosis (anti-TB) drug Rifampicin (RIF).

Heliotropium crispum-mediated assembly of silver nanoparticles exhibit profound antibacterial and anti-biofilm effects against multiple drug-resistant bacteria, but its stability and biocompatibility remain a hurdle in commercialization. Herein, we adopted a surface chemistry-based steric repulsion approach to investigate the colloidal stability of H. crispum silver nanoparticles (HC-AgNPs) and determine its application as a commercial antibacterial formulation. Two primary silver nanoparticles (AgNPs) were synthesized, i.e., HC-AgNPs and citrate-HC-AgNPs initially, which were then modulated to assemble various derivatives of AgNPs using polyethylene glycol (PEG) and polyvinylpyrrolidone (PVP) as stabilizing agents. Various parameters were assessed to investigate the morphology, colloidal physio-chemistry, and surface capping using various analytical techniques, such as UV–Vis spectrophotometer, zeta–dynamic light scattering (DLS), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM, and transmission electron microscopy (TEM). Selective AgNPs were then screened on the basis of stability for up to 8 months, heat resistance at 100 °C, and bioactivity via MTT assay using HEP-2, MCF-7, and HCEC cell lines. The UV–Vis and electron microscope results revealed that HC-AgNPs confer near-spherical and slight triangular-shaped morphology and the size of all synthesized AgNPs is in the range of 400–450 nm. All AgNPs synthesized from HC-source have characteristic FTIR peaks recorded near 2931 cm−1, 1996 cm−1, and 825 cm−1. This study highlights promising evidence for the commercial application of HC-AgNPs as an antimicrobial agent. Additionally, it provides a methodology for modulating the surface capping of biological nanoparticles and assesses its corresponding effect on the stability.

Emulsion templating is at the forefront of producing a wide array of porous materials that offers interconnected porous structure, easy permeability, homogeneous flow‐through, high diffusion rates, convective mass transfer, and direct accessibility to interact with atoms/ions/molecules throughout the exterior and interior of the bulk. These interesting features together with easily available ingredients, facile preparation methods, flexible pore‐size tuning protocols, controlled surface modification strategies, good physicochemical and dimensional stability, lightweight, convenient processing and subsequent recovery, superior pollutants remediation/monitoring performance, and decent recyclability underscore the benchmark potential of the emulsion‐templated porous materials in large‐scale practical environmental applications. To this end, many research breakthroughs in emulsion templating technique witnessed by the recent achievements have been widely unfolded and currently being extensively explored to address many of the environmental challenges. Taking into account the burgeoning progress of the emulsion‐templated porous materials in the environmental field, this review article provides a conceptual overview of emulsions and emulsion templating technique, sums up the general procedures to design and fabricate many state‐of‐the‐art emulsion‐templated porous materials, and presents a critical overview of their marked momentum in adsorption, separation, disinfection, catalysis/degradation, capture, and sensing of the inorganic, organic and biological contaminants in water and air., Understanding the structure‐property relationship of materials‐by‐design is very useful to optimize materials predictive functions. Porous materials, especially those prepared via emulsion templating, offer great promise in ubiquitous environmental remediation applications and beyond owing to their interconnected porous structure, enhanced permeability, tunable chemistry, homogeneous flow‐through, high diffusion rates, convective mass transfer, and thorough accessibility for direct interaction with the pollutants for subsequent removal.

Metal nanoclusters (NCs, size ≤2 nm) are emerging materials in catalysis owing to their unique catalytic and electronic properties such as high surface/volume ratio, high redox potential, plethora of surface active sites, and dynamic behavior on a suitable support during catalysis. Herein, in situ growth of ultrasmall and robust Co@β-Co(OH)2 NCs (≈2 nm) hosted in a honeycomb-like 3D N-enriched carbon network was developed for water-oxidation catalysis with extremely small onset potential (1.44 V). Overpotentials of 220 and 270 mV were required to achieve a current density of 10 mA cm-2 and 100 mA cm-2 , respectively, in alkaline medium (1 m KOH). More promisingly, at η10 =240 mV, the prolonged oxygen evolution process (>130 h) with faradaic efficiency >95 % at a reaction rate of 22 s-1 at 1.46 V further substantiated the key role of the ultrasmall supported NCs, which outperformed the benchmark electrocatalysts (RuO2 /IrO2 ) and NCs reported so far. It is anticipated that the high redox potential of NCs with regeneratable active sites and their concerted synergistic effects with the N-enriched porous/flexible carbon network are inherently worth considering to enhance the mass/charge transport owing to the nanoscale interfacial collaboration across the electrode/electrolyte boundary, thereby efficiently energizing the sluggish/challenging oxygen evolution process.

Nanobiotechnology is the emerging field of science as it deals with the properties on nanoscale dimension and it can make the revolution in the diagnostic and therapeutic fields. The purpose of this review is to summarize the synthesis, types, properties and applications of gold nanoparticles. Gold nanoparticles are widely studied metal nanoparticles because of their unique physical and chemical properties that are different from bulk materials. Gold nanoparticles possess notable optoelectronic properties that are dependent on the shape and size of nanoparticles. They have large surface-to-volume ratio, excellent biocompatibility, and low toxicity which are very useful and make them an important tool in nanobiotechnology. This review reveals the characterization of gold nanoparticles by using UV–Vis spectroscopy, TEM and DLS. For their ability to target and efficient drug delivery, they have been extensively used for enhanced radiation in the field of radiation therapy. Gold nanoparticles have several other applications in the biomedical field like detection of very sensitive analytes, protein and virus and even they play role in killing cancer cells by hyperthermal treatment. A time is not far for fabrication and manipulation of new nanomaterials to be engineered for applications including therapeutic delivery, biosensors and bioimaging for biomedical use.

Tainting of waterbodies with noxious industrial waste is the gravest environmental concern of the day that continues to wreak inevitable havoc on human health. To cleanup these hard-to-remove life-threatening water contaminants, we have prepared hierarchically porous poly(acrylic acid) beads by emulsion templating. These emulsion-templated macroporous polymer beads not only mediate the synthesis of Fe3O4 nanoparticles inside their porous network using a coprecipitation approach but, in turn, create diverse anchoring sites to immobilize an additional poly(acrylic acid) active layer onto the nanocomposite beads. These post-synthetically modified nanocomposite beads with macropores and abundant acrylic acid moieties offer the ready mass transfer and fair advantage of relatively higher overall negative charge to efficiently adsorb lead [Pb(II)] and crystal violet with impressive performance-even superior to many of the materials explored in this regard so far. Furthermore, the strong entanglement of nanoparticles in the porous polymeric scaffolds tackles the curb of trade-off between all-round effective remediation and secondary pollution and the millimeter size eases their processing and recovery during the adsorption tests, thereby making these materials practically worthwhile.

PurposeThis study aimed to present fabrication of novel poly(lactic acid) (PLA) mediated chitosan nanoparticles (CNPs) and their impregnation on cotton fabric for enhanced antibacterial and physical properties.Design/methodology/approachThe PLA-CNPs were characterized using scanning electron microscopy, energy dispersive x-ray spectroscopy, Fourier transform infrared (FTIR) spectroscopy and zeta size analysis. The prepared PLA-CNPs were impregnated on cotton fabric via pad-dry-cure method. The finished cotton fabric was then characterized for its antibacterial activity, functional and other physical textile properties.FindingsThe spectral and optical properties demonstrate that the NPs expressed spherical morphologies with an average particle diameter of 88.02 nm. The antibacterial activity of treated fabrics ranged between 75 and 90 per cent depending on the concentration of PLA-CNPs.Practical implicationsBecause of enhanced awareness and desire for ecofriendly products, the use of sustainable and functional textiles is increasing day by day. For the said purpose, industries are using different chemical treatments to achieve desired end functionality. Currently, different synthetic antibacterial agents are in practice, but they lack sustainable approach to save the environment. In this study, the researchers have developed PLA mediated CNPs for sustainable antibacterial and physical properties of treated cotton fabric.Originality/valueTo the best of the authors’ knowledge, this is first attempt to fabricate PLA-incorporated CNPs for application on cotton fabric followed by a detailed characterization.

Significant efforts have been devoted to develop efficient visible-light-driven photocatalysts for the conversion of CO2 to chemical fuels. The photocatalytic efficiency for this transformation largely depends on CO2 adsorption and diffusion. However, the CO2 adsorption on the surface of photocatalysts is generally low due to their low specific surface area and the lack of matched pores. Here we report a well-defined porous hypercrosslinked polymer-TiO2-graphene composite structure with relatively high surface area i.e., 988 m2 g−1 and CO2 uptake capacity i.e., 12.87 wt%. This composite shows high photocatalytic performance especially for CH4 production, i.e., 27.62 μmol g−1 h−1, under mild reaction conditions without the use of sacrificial reagents or precious metal co-catalysts. The enhanced CO2 reactivity can be ascribed to their improved CO2 adsorption and diffusion, visible-light absorption, and photo-generated charge separation efficiency. This strategy provides new insights into the combination of microporous organic polymers with photocatalysts for solar-to-fuel conversion.

The development of metal nanoparticles supported in porous materials is important for the development of highly efficient heterogeneous catalysis. Because of the quantum-size effect, the size of th...

The demand of high anodic potential for oxygen evolution reaction (OER) because of its sluggish kinetics limits the overall efficiency and practical applications of electrochemical water splitting ...

Copper nanoclusters (Cu NCs) are generally formed by several to dozens of atoms. Because of wide range of raw materials and cheap prices, Cu NCs have attracted scientists&rsquo, special attention. However, Cu NCs tend to undergo oxidation easily. Thus, there is a dire need to develop a synthetic protocol for preparing fluorescent Cu NCs with high QY and better stability. Herein, we report a one-step method for preparing stable blue-green fluorescent copper nanoclusters using glutathione (GSH) as both a reducing agent and a stabilizing agent. High-resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS) and electrospray ionization mass spectrometer (ESI-MS) were used to characterize the resulting Cu NCs. The as-prepared Cu NCs@GSH possess an ultrasmall size (2.3 &plusmn, 0.4 nm), blue-green fluorescence with decent quantum yield (6.2%) and good stability. MTT results clearly suggest that the Cu NCs@GSH are biocompatible. After incubated with EB-labeled HEK293T cells, the Cu NCs mainly accumulated in nuclei of the cells, suggesting that the as-prepared Cu NCs could potentially be used as the fluorescent probe for applications in cellular imaging.

We report the synthesis, characterization and evaluation of lecithin-drug hybrid nanocarriers (NCs) with enhanced oral bioavailability and anti-parasitic potential for poorly water-soluble drugs. Amphotericin B (AmB), a poor water-soluble drug with poor membrane penetrating ability, was selected as a model drug to demonstrate the potential of the lecithin-drug hybrid NCs. Lec-AmB NCs were prepared by the self-assembly of lecithin into nanoparticles (NPs) at a critical micellar concentration of 4 mg ml−1 and into liposomes at a critical liposomal concentration of 53 mg ml−1 in aqueous systems. The Lec-AmB NPs (200–300 nm) were further coated with polyethylene glycol (MW 600) and Tween 20, whereas the liposomes (70–90 nm) were used as such for this study. The Lec-AmB NCs were evaluated for their ability to boost in vivo oral pharmacokinetic parameters in rabbits and in vitro anti-leishmanial activity against the promastigotes of Leishmania tropica. A reciprocal relationship was observed between the size and drug encapsulation efficiency of the NPs, but no such relationship was observed in the case of the liposomes. More importantly, the oral bioavailability and anti-leishmanial activity of Lec-AmB NPs was enhanced up to 21- and 6.3-fold, and 21- and 2-fold, respectively, in the case of the liposomes. The improvement in the bioavailability and anti-leishmanial activity is very significant compared to the deoxycholate complex of AmB (water soluble, injectable market product: Anfotericina FADA®), and this study, thus shows the promising potential of easy-to-prepare NCs with improved therapeutic efficiency using phosphocholine-based biocompatible surfactants.

Present research demonstrated the crosslinking of Cydonia oblonga seeds hydrogel using citric acid (CA) and evaluated its stimuli-responsive swelling properties at different biomimetic pH, swelling/deswelling behavior against different fluids and sustained release potential in orally administered tablet formulation. Cross-linked C. oblonga hydrogel (CL-COH) was synthesized using four concentrations of CA, i.e., 1.25%, 2.5%, 5% and 10% and characterized through Fourier transform infrared (FTIR) spectroscopic analysis. CL-COH exhibited high swelling capacity at pH 6.8, 7.4 and in deionized water whereas, insignificant swelling was observed at pH 1.2. Swelling/deswelling response of CL-COH (2.5% CA) at pH 7.4 and 1.2, in deionized water and ethanol, and deionized water and normal saline were remarkable and reproducible results were obtained even after four cycles. Scanning electron microscopy (SEM) images of CL-COH indicated evenly distributed web of interconnected macro-pores. CL-COH was used as a pH-sensitive sustained release material for the preparation of oral tablet formulation of levosulpiride. In vitro drug release study revealed that the drug release followed zero-order kinetics and drug release mechanism was found as a super case II transport. Non-thrombogenic and non-hemolytic potential of CL-COH was ascertained through haemocompatibility studies. Therefore, CL-COH can be a versatile stimuli-responsive and biocompatible polysaccharide-based material for zero-order sustained release of drugs.

We propose a facile, cost-effective and commercially viable method to prepare durable superhydrophobic surfaces using a bio-waste material. The naturally available nanostructured sawdust particles were combined with polychlroprene adhesive, carbon soot and silicon polymer to formulate superhydrophobic coatings. Saw dust particles were bonded on the substrate using polychloroprene adhesive, which was followed by depositing silicone by dip-coating to produce a superhydrophobic surface. To further improve the mechanical and superhdyrophobic properties, a thin layer of carbon soot was deposited and stabilized by second layer of silicone. Electron microscopy, spectroscopy and goniometry were employed for microstructural analysis, chemical nature and the contact angle measurements of the coatings. After quantifying the excellent response against mechanical abrasion, the superhydrophobic coating was employed on a mesh to demonstrate its application for oil/water separation. It was observed that the coated mesh successfully separated both light and heavy oils from oil/water mixtures with high separation efficiency and therefore has the potential for large-scale separation of oil/water mixtures.

Nano/microscale TiO2 materials and their composites have reached the pinnacle of their photocatalytic performances to destroy persistent organic pollutants and waterborne microorganisms, but their practical applications are limited by the drawbacks associated with their stability, leaching, processing and separation. To overcome these shortcomings, we have prepared hierarchically porous nanostructured TiO2 macrobeads via an exotemplating or nanocasting strategy by infiltrating the TiO2 sol into the emulsion-templated porous polyacrylamide scaffold followed by its gelation, drying and calcination. The nanoscale TiO2 building units tailor the shape of the porous polymeric network after calcination thereby retaining the macroscale morphology of polymer beads after template removal. A novel combination of the hierarchical macroporosity, orderly crystalline anatase nature, nanoscale feature and good surface area revealed by the relevant characterization tools makes these TiO2 scaffolds particularly effective for superior degradation of methylene blue with the enhanced rate constant and efficient disinfection of E. coli and S. aureus under UV light. The macrosize and mechanical stability of these purely TiO2 beaded architectures have several potential advantages over conventional TiO2 nanocomposites and slurry systems to address the inherent bottlenecks of secondary contamination, difficult operation and energy-intensive post-recovery processes that are indeed deemed to be the barriers to develop practically useful water treatment technologies.

Sunlight driven heterostructured photocatalysts have attracted remarkable attention for the degradation of organic pollutants, including toxic dyes. In present study, the synthesis of TiO2 NPs anchored α-MnO2 nanorods based catalyst has been reported for the degradation of CBB R-250, a widely used textile dye. The FE-SEM analysis showed the rod-like structure of α-MnO2, uniformly decorated with TiO2 NPs, further confirmed by EDX. The XPS revealed the binding energy and oxidation states of prepared photocatalyst. Designed photocatalyst efficiently degraded (98.35%) dye after 30 min sunlight irradiation. The narrow bandgap (2.8 eV) of the designed photocatalyst was one of the key factors for enhanced photocatalytic activity. CBB degradation reaction followed pseudo-first order kinetics with maximum removal efficiency of > 85%. The ESI-MS2 mass spectra has further validated the dye mineralization. The biosafety of designed catalyst was checked in HEK293T cells with IC50 = 160.7, which is considered as benign to human and their environment.

Durable superhydrophobic composite coating of alumina nanoparticles and PDMS was developed to avoid the degradation of wood in humid environment. For this purpose, commercially available alumina nanoparticles were employed to form a rough surface, which was then chemically modified with polydiemethylsiloxane (PDMS) to attain superhydrophobic properties. Several alternate layers of nanoparticles and PDMS were prepared to ensure durable superhydrophobic properties, which were evaluated by emery paper abrasion and water impact tests. The optimized coating was applied on wood substrates to restrict their contact with water. The superhydrophobic character of wood specimens after coating was examined by change in contact angle with time and observing the water absorbance in coated and uncoated wood specimens.

Water, the driver of nature, has always been polluted by the blind hurling of highly toxic contaminants, but human-friendly science has continuously been presenting better avenues to help solve these challenging issues. In this connection, the present study introduces novel nanocomposites composed of emulsion-templated hierarchically porous poly(1-vinylimidazole) beads loaded with the silver nanoparticles generated via an in situ approach. These nanocomposites have been thoroughly characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis, Brunauer-Emmett-Teller, and field emission scanning electron microscopy. The appropriate surface chemistry, good thermal stability, swelling behavior, porosity, and nanodimensions contributed to achieve very good performance in water treatment. Owing to their easier handling and separation, these novel nanocomposites are highly efficient to remove arsenic and eriochrome black T with decent adsorption capacities in addition to the inactivation and killing of Escherichia coli (Gram-negative) and Staphylococcus aureus (Gram-positive) bacteria.

The large-scale industrial applications of superhydrophobic surfaces are restricted by their poor mechanical properties. We present a facile method to produce a mechanically durable superhydrophobic surface on building materials, which has the added feature to restore its properties after severe abrasion. These superhydrophobic surfaces were fabricated, from hydrophobic silica nanoparticles and commercially available spray adhesive, on three commercially available construction materials i.e. bricks, marble and glass. The prepared surfaces were able to sustain the impact of sand particles traveling at a speed of 11.26 km/h, and also revamp their superhydrophobic character by simple acetone treatment upon receiving severe damages from emery paper and knife scratches.

Microporous organic capsules with hollow interiors have received enormous attention due to their unusual encapsulation efficiency to confine chemicals within their hollow cavities and prompted controlled release by circumventing their ripening or poisoning. To this end, herein, we report the design and synthesis of carboxylic group functionalized hollow microporous organic capsules (HMOCs) using a facile emulsion polymerization technique that show extraordinary high encapsulation efficiency (up to 98%) of morphine·HCl and its promising prolonged release. The functionalized HMOCs are found to release the drug at a rate which is proportional to the amount of drug remaining in its interior. Due to the presence of hollow and porous morphologies, they possess high BET surface areas, i.e. up to 974 m2 g-1. Moreover, the in vivo results showed that functionalized HMOCs can offer slow release of active drug molecules and attenuate the level of writhing response over 72 h of intraperitoneal injection. The functionalized HMOCs, therefore, present a new class of potential drug delivery systems that can maintain the slow and prolonged release of analgesics by lowering the dosage and avoid frequent administration.

Emulsion templating has emerged as a cutting-edge technique to prepare a wide array of porous polymer–metal nanocomposites with intriguing properties. Using this strategy, we set out to prepare novel hierarchically porous poly(vinylsulfonic acid) beads, which were then used for the in situ production of silver nanoparticles to obtain poly(vinylsulfonic acid)–Ag nanocomposite beads via a facile approach. Owing to their multimodal macro-meso-/microporosity that accounts for their decent BET surface areas (170.75–197.74 m2/g) and easier mass diffusion and transport together with the synergistic benefits of very small silver nanoparticles (down to ∼3.77 nm), the nanocomposite beads are found effective to remove Hg(II) and RhB and to kill Escherichia coli (Gram-negative) and Staphylococcus aureus (Gram-positive) bacteria. The adsorption capacities (167.98–190.58 mg/g) of these materials for Hg(II) surpass some recently reported benchmark materials. The larger size (1.56 ± 0.20–1.50 ± 0.14 mm) of the beads that...

This study is carried out on polysaccharide-based hydrogel extracted from the seeds of Ocimum basilicum L. for its evaluation as a superabsorbent and stimuli responsive biomaterial for sustained release drug delivery system. O. basilicum (Syn: Basil) seed hydrogel (BSH) expressed high swelling capacity at pH 6.8 and 7.4 and deionized water. Highly reversible on-off switching (swelling-deswelling) behavior of BSH was ascertained in deionized water and ethanol, pH 7.4 and 1.2, and deionized water and normal saline. Scanning electron microscopy (SEM) of BSH has revealed macroporous structure of BSH having average pore size of 1.92 ± 3.83 μm noted after swelling and lyophilization. BSH containing tablet formulations showed a sustained release pattern of diclofenac sodium (DS) which is dependent on the concentration of BSH. When comparing with commercially available formulation of DS, even better sustained release behavior of DS was observed in BSH-based formulation. Super case-II transport mechanism is followed by the DS release from BSH matrix tablet. Haemocompatibility studies of BSH were also performed and found it nonhaemolytic and nonthrombogenic.

This study reports on a simple approach for the fabrication of an electrode modified with biocompatible C-dot wrapped ZnO nanoparticles for selective photoelectrochemical monitoring of H2O2 released from living cells. The biocompatibility of the ZnO nanoparticles was confirmed through in-vitro cellular testing using the MTT assay on Huh7 cell lines. The ZnO nanoparticles wrapped with dopamine-derived C-dots possess numerous catalytically active sites, excessive surface defects, good electrical conductivity, and efficient separation ability of photo-induced electrons and holes. These properties offer highly sensitive and selective non-enzymatic photo-electrochemical monitoring of H2O2 released from HeLa cells after stimulation with N-formylmethionyl-leucyl-phenylalanine. The sensor has a wide linear range (20–800 nM), low detection limit (2.4 nM), and reliable reproducibility, this implying its suitability for biological and biomedical applications.

We demonstrate the synthesis of hydrophobic silica nanoparticles from sodium silicate and their application in separation of the oil–water mixture. For this, hydrophobic silica nanoparticles of size 35 ± 8 nm were initially synthesized by sol–gel method using sodium silicate and trimethylchlorosilane, and further deposited on commercially available filter paper and polyurethane foam by dip coating technique. The coating cycles were optimized for filter paper to ensure that fibers of the filter paper have been completely covered with hydrophobic silica nanoparticles to provide an ideal porous superhydrophobic/superoleophilic framework for gravity based separation of oil–water mixtures. It was confirmed by water contact angle of ~155° and sliding angle

We report the synthesis of hydrophobic silica nanoparticles of different mean sizes ranging in diameter from 48 to 260 nm for the preparation of superhydrophobic composites. The nanoparticles were synthesized by adding methanol into aqueous solution of sodium silicate followed by the addition of trimethylchlorosilane. The different mean sizes of nanoparticles were achieved by varying the concentration of sodium silicate solution in methanol. It was found that nanoparticles with bi-modal distribution demonstrated superior hydrophobic properties owing to their hierarchical structure. The nanoparticles with bi-modal size distribution were deposited on cotton fabric and fibers to prepare superhydrophobic composites using an immersion technique. The prepared composites were used for the separation of four oil-water mixtures; the composites containing fabric separated oil-water mixtures via filtration while composites containing fibers separated oil-water mixture by absorption.

Ion implantation has a potential to modify the surface properties and to produce thin conductive layers in insulating polymers. For this purpose, poly-allyl-diglycol-carbonate (CR-39) was implanted by 400 keV Au+ions with ion fluences ranging from 5 × 1013ions/cm2to 5 × 1015ions/cm2. The chemical, morphological and optical properties of implanted CR-39 were analyzed using Raman, Fourier transform infrared (FT-IR) spectroscopy, atomic force microscopy (AFM) and UV-Vis spectroscopy. The electrical conductivity of implanted samples was determined through four-point probe technique. Raman spectroscopy revealed the formation of carbonaceous structures in the implanted layer of CR-39. From FT-IR spectroscopy analysis, changes in functional groups of CR-39 after ion implantation were observed. AFM studies revealed that morphology and surface roughness of implanted samples depend on the fluence of Au ions. The optical band gap of implanted samples decreased from 3.15 eV (for pristine) to 1.05 eV (for sample implanted at 5 × 1015ions/cm2). The electrical conductivity was observed to increase with the ion fluence. It is suggested that due to an increase in ion fluence, the carbonaceous structures formed in the implanted region are responsible for the increase in electrical conductivity.

TiO 2 anatase photocatalysts with ca. 2, 4 and 8 wt.% copper metal loading have been employed for the photocatalytic degradation of textile dyes (one of the major contaminants in effluent from textile industries around the world) and their degradation efficiencies compared with benchmark Degussa P25. In order to investigate their surface and bulk composition, all catalysts were characterized using XRD, UV–vis, XPS and TEM techniques. TEM and XPS results confirmed the presence of Cu in its oxide form (Cu 2 O-CuO). Under optimized conditions (i.e. catalyst dose of 125 mg L −1 and initial dye concentration of 5 mg L −1 ), Degussa P25 showed 76% degradation efficiency for primary reactive blue 49 (RB 49) dye in 80 min. However, under the same optimized conditions, a complete primary RB 49 dye removal was observed at ca. 4 wt.% Cu 2 O-CuO/TiO 2 catalyst. Kinetics analysis of photodegradation ( k d ) nearly followed a pseudo-first-order kinetic model with a regression coefficient (R 2 ) value in the range of 0.97–0.86 for 4 wt.% Cu 2 O-CuO/TiO 2 catalyst. These results indicate that non noble supported TiO 2 anatase may be a better choice for photocatalytic dye degradation as compared to other commercially available photocatalysts.

Gold nanoparticles (Au NPs) of different sizes were supported on fibrous silica nanospheres (KCC-1) by various methods. The size and the location of the Au NPs on the support were found to depend on the preparation method. The KCC-1-supported Au NPs were thoroughly characterized by using HR-TEM, XRD, X-ray photoelectron spectroscopy, UV, and Brunauer–Emmett–Teller surface area measurements and were applied in catalysis for the oxidation of CO. The catalytic performance is discussed in relation to the morphological properties of KCC-1.

Achieving water splitting at low overpotential with high oxygen evolution efficiency and stability is important for realizing solar to chemical energy conversion devices. Herein we report the synthesis, characterization and electrochemical evaluation of highly active nickel nanoclusters (Ni NCs) for water oxidation at low overpotential. These atomically precise and monodisperse Ni NCs are characterized by using UV-visible absorption spectroscopy, single crystal X-ray diffraction and mass spectrometry. The molecular formulae of these Ni NCs are found to be Ni4(PET)8 and Ni6(PET)12 and are highly active electrocatalysts for oxygen evolution without any pre-conditioning. Ni4(PET)8 are slightly better catalysts than Ni6(PET)12 which initiate oxygen evolution at an amazingly low overpotential of ∼1.51 V (vs. RHE; η≈ 280 mV). The peak oxygen evolution current density (J) of ∼150 mA cm(-2) at 2.0 V (vs. RHE) with a Tafel slope of 38 mV dec(-1) is observed using Ni4(PET)8. These results are comparable to the state-of-the-art RuO2 electrocatalyst, which is highly expensive and rare compared to Ni-based materials. Sustained oxygen generation for several hours with an applied current density of 20 mA cm(-2) demonstrates the long-term stability and activity of these Ni NCs towards electrocatalytic water oxidation. This unique approach provides a facile method to prepare cost-effective, nanoscale and highly efficient electrocatalysts for water oxidation.

Gold nanoparticles and nanocomposites have high catalytic performance for several chemical reactions. Here we present gold and iron oxide nanoparticle modified polymer capsules as porous and multifunctional platforms for catalysis. Layer-by-layer polyelectrolyte microcapsules were formed on calcium carbonate template cores loaded with gold nanoparticles, allowing for high gold loading of the capsules. Magnetic nanoparticles were incorporated in the polymeric shells of the capsules, allowing for magnetic separation. The influence on the catalytic behaviour of gold was studied in terms of the nanoparticle size, the presence of a polymeric shell, and the presence of the magnetic nanoparticles in the shell, by using the model electron transfer reaction between hexacyanoferrate(III) and borohydride.

Folate grafted and thiolated chitosan was synthesized and wrapped on the surface of mixed phosphatidylcholine based nanoliposomes (NLs) to improve the oral absorption and targeted pharmacological activity of anti-cancer drugs against breast cancer. In this study, a chitosan derived thiomer, having intrinsic properties of P-glycoprotein (P-gp) efflux pump inhibition, mucoadhesion and controlled drug release at a target site, was exploited to improve the performance of docetaxel (DTX) loaded NLs for better oral pharmacokinetics, targeted anti-cancer activity, liposomal stability and the physical characteristics of NLs. Thiomer enveloped nanoliposomes (ENLs) and bare nanoliposomes (NLs) were synthesized with the ingredient ratio pre-determined via Response Surface Methodology (RSM) plots by Design Expert® software. ENLs and NLs were thoroughly characterized for their surface chemistry, particle size, zeta potential, PDI, encapsulation efficiency, stability and release profile. ENLs were spherical in shape with a particle size of 328.5 ± 30 nm, a positive zeta potential of 18.81 ± 2.45 and a high encapsulation efficiency of 83% for DTX. Controlled release of DTX from formulations was observed for over 72 h for each formulation. The presence of thiol groups at the surface of the ENLs resulted in higher swelling and in situ gelling properties compared to the corresponding NLs. Furthermore, ENL/mucin mixtures showed a time dependent increase in viscosity for up to 12 h, leading to a 19.07-fold increased viscosity. Ex vivo permeation and P-glycoprotein inhibiting properties, studied in rat's small intestine, showed a 9.6-fold higher permeation and 13-fold enhancement of DTX in the presence of ENLs. In vitro cytotoxicity studies indicated that the ENLs can efficiently kill MD-MB-231 breast cancer cells with 200 fold lower IC50 values than DTX alone as a positive control. The pharmacokinetic study revealed that the ENLs significantly improved the oral bioavailability of DTX i.e. up to 13.6 fold as compared to an aqueous dispersion of DTX. Therefore, these enveloped hybrid nanoliposomes (ENLs) have the potential to be developed as useful nanocarriers for efficient oral delivery and breast cancer management using DTX.

Band gap tuning of nanomaterials is a current field of interest in order to transform UV-light active catalysts into visible light driven catalysts. Tungsten-doped SnO2 (W@SnO2) nanospheres (NS) with dopant concentration ranging from 0 to 6 mol%, were prepared and characterized by powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), inductively coupled plasma optical emission spectrometry (ICP-OES) and UV-Visible spectroscopy. The UV-Vis spectroscopic results revealed the shifting of absorption edges of SnO2 to the visible portion of the spectrum, and the XRD peaks shifted to the lower 2θ values with increase of the tungsten contents from 0 to 6 mol%. These results were further supported by density functional theory (DFT) calculations. W@SnO2 NS were evaluated for photocatalytic degradation of crystal violet (CV) dye under the optimized experimental conditions. The liquid chromatography mass spectrometric (LCMS) analysis of the dye solution before and after degradation experiments demonstrated complete mineralization of dye probably to H2O and CO2. Moreover, the thin films of 6 mol% W@SnO2 catalyst were casted to make the photocatalyst simply reusable. The photocatalytic results when compared with Degussa-P25 (standard titania) under light irradiation (both in UV and Vis), showed that the use of thin film can be a preferred choice for visible light harvesting photocatalytic degradation. Furthermore, the synthesized materials were assessed for electrocatalytic water splitting, with an overpotential of 280 mV and 144 mV to execute the OER and HER respectively, in alkaline medium (l M KOH).

The design of cost-effective and competent electrochemical water splitting module that is functional in a wide pH range is still a formidable challenge for viable H2 production. Herein, we report control synthesis of Ni/Ni3C nanoparticles (NPs) induced engineering of the nitrogen-enriched carbon-nanotubes (NCNT) of three different sizes/morphologies by the pyrolysis of melamine with Ni(NO3)·6H2O at various stoichiometric ratios (0.5-wt%, 2-wt% and 4-wt% of Ni). The catalytic potential and structural integrity of the in-situ self-assembled hybrid material was explored and found very effective to catalyse both OER and HER in a broad pH range (0-14). Promisingly, the nanostructuring of the Ni/Ni3C NPs and subsequently the diameter of the NCNT hold the catalytic potential, where 0.5-Ni/Ni3C@NCNT (average size ≈ 15–20 nm) showed remarkable activity for OER (ƞ10-base/acid/neutral = 280/400/600 mV, Tafel slopebase = 42 mV/dec) and HER (ƞ10-acid/base/neutral = 210/290/370 mV, Tafel slopeacid = 40 mV/dec). It is anticipated, that favourable electronic modulation of Ni/Ni3C, structural strain of NCNT, and possible concerted synergistic effect of the hybrid/doped nanocarbons with metal-carbide hold a great potential in this regard, and such modular strategies tailoring the structural-performance relationship may provide the guidance towards the designing of commercially viable electrocatalysts in this regard.

A sustainable future demands innovative breakthroughs in science and technology today, especially in the energy sector. Earth-abundant resources can be explored and used to develop renewable and sustainable resources of energy to meet the ever-increasing global energy demand. Efficient solar-powered conversion systems exploiting inexpensive and robust catalytic materials for the photo- and photo-electro-catalytic water splitting, photovoltaic cells, fuel cells, and usage of waste products (such as CO2 ) as chemical fuels are appealing solutions. Many electrocatalysts and nanomaterials have been extensively studied in this regard. Low overpotentials, catalytic stability, and accessibility remain major challenges. Metal nanoclusters (NCs, ≤3 nm) with dimensions between molecule and nanoparticles (NPs) are innovative materials in catalysis. They behave like a "superatom" with exciting size- and facet-dependent properties and dynamic intrinsic characteristics. Being an emerging field in recent scientific endeavors, metal NCs are believed to replace the natural photosystem II for the generation of green electrons in a viable way to facilitate the challenging catalytic processes in energy-conversion schemes. This Review aims to discuss metal NCs in terms of their unique physicochemical properties, possible synthetic approaches by wet chemistry, and various applications (mostly recent advances in the electrochemical and photo-electrochemical water splitting cycle and the oxygen reduction reaction in fuel cells). Moreover, the significant role that MNCs play in dye-sensitized solar cells and nanoarrays as a light-harvesting antenna, the electrochemical reduction of CO2 into fuels, and concluding remarks about the present and future perspectives of MNCs in the frontiers of surface science are also critically reviewed.

A two-step high temperature colloidal doping technique has been used to synthesis Co-Ni co-doped CdS/ZnS core/shell nanocrystals in organic phase. Co-Ni ions were incorporated into the CdS quantum dots core pursued by ZnS shell (six monolayers) which was developed on top of it. The co-doped nanocrystals were further characterized usingtransmission electron microscopy (TEM),X-ray diffraction (XRD), ultraviolet-visible (UV-VIS) spectroscopy and photoluminescence (PL) spectroscopy measurements. The co-doped CdS/ZnS nanocrystals show two peaks; the sharp emission peak is due to CdS quantum dot at 440 nm while the broad emission peak (520–650nm) is due typical to Co-Ni ions as compared to undoped CdS/ZnS nanocrystals.

Two kinds of POSS-based organic–inorganic hybrid porous materials have been synthesized via Friedel–Crafts and Scholl coupling reactions, for the first time, using low-cost building blocks i.e., octaphenylsilsesquioxanes and simple knitting approaches to obtain high Brunauer–Emmett–Teller (BET) surface area porous polyhedral oligomeric silsesquioxane (POSS)-based hybrid materials. N2 sorption isotherms of the polymers show that both these materials are predominantly microporous and mesoporous with BET surface areas of 795 m2 g−1 for the polymer of octaphenylsilsesquioxanes-1 (POPS-1) and 472 m2 g−1 for the polymer of octaphenylsilsesquioxanes-2 (POPS-2). Moreover, POPS-1 can reversibly adsorb 9.73 wt% CO2 (1 bar and 273 K) and 0.89 wt% H2 (1.13 bar and 77 K), and POPS-2 shows moderate gas uptake with 8.12 wt% CO2 (1 bar and 273 K) and 0.64 wt% H2 (1.13 bar and 77 K). In addition, the structural integrity of POSS based building blocks was completely preserved under relatively strong acidic conditions.

The key challenge in the formation of stable CO2-in-water (C/W) emulsions has always been the availability of effective surfactants. Most of the surfactants being used for this purpose are expensive and difficult to synthesize, rendering the formation of C/W emulsions an uneconomical and unfavorable process. In this work, we report the use of commercial polyvinyl alcohol as an effective stabilizer for the formation of C/W emulsions at low temperatures. Porous emulsion-templated materials were prepared by the polymerization of the continuous phase of C/W emulsions. The open-cell morphology of the emulsion-templated materials was observed by scanning electron microscopy. To tune the morphology of the porous structures, the influence of the stabilizer concentration and the process of polymerization were investigated. These porous PAM materials were further evaluated for cellular growth and proliferation to demonstrate their applications in tissue engineering.

Novel layered microporous polymers with high surface area and gas storage were prepared by low-cost solvent knitting method., Two-dimensional (2D) nanomaterials, especially 2D organic nanomaterials with unprecedentedly diverse and controlled structure, have attracted decent scientific interest. Among the preparation strategies, the top-down approach is one of the considered low-cost and scalable strategies to obtain 2D organic nanomaterials. However, some factors of their layered counterparts limited the development and potential applications of 2D organic nanomaterials, such as type, stability, and strict synthetic conditions of layered counterparts. We report a class of layered solvent knitting hyper-cross-linked microporous polymers (SHCPs) prepared by improving Friedel-Crafts reaction and using dichloroalkane as an economical solvent, stable electrophilic reagent, and external cross-linker at low temperature, which could be used as layered counterparts to obtain previously unknown 2D SHCP nanosheets by method of ultrasonic-assisted solvent exfoliation. This efficient and low-cost strategy can produce previously unreported microporous organic polymers with layered structure and high surface area and gas storage capacity. The pore structure and surface area of these polymers can be controlled by tuning the chain length of the solvent, the molar ratio of AlCl3, and the size of monomers. Furthermore, we successfully obtain an unprecedentedly high–surface area HCP material (3002 m2 g−1), which shows decent gas storage capacity (4.82 mmol g−1 at 273 K and 1.00 bar for CO2; 12.40 mmol g−1 at 77.3 K and 1.13 bar for H2). This finding provides an opportunity for breaking the constraint of former knitting methods and opening up avenues for the design and synthesis of previously unknown layered HCP materials.

Deposition of nanoparticles on the surface of a variety of materials is a subject of great interest due to their potential applications in electronic devices, sensing, catalysis and bio-medical sciences. In this context, we have explored and compared various methodologies to generate gold and silver nanoparticles on the surface of cellulose fibers. It was found that boiling of the cellulose fibers in alkaline solution of gold and silver salts led to the formation and immobilization of gold and silver nanoparticles. However, in case of lecithin treated and thiol-modified cellulose fibers, high temperature was not essentially required for the formation and deposition of nanoparticles on cellulose substrate. In both these cases, fairly uniform metal nanoparticles were obtained in good yields (~43 wt% gold loading in case of thiol modified cellulose fibers) at room temperature. Borohydride-reduction method resulted in relatively lower loading (~22 wt%) with a wide size distribution of gold and silver nanoparticles on cellulose fibers. All these nanoparticle–cellulose composites were thoroughly characterized using scanning electron microscopy, energy dispersive X-ray, Fourier transform infrared spectroscopy, UV–visible spectroscopy, and elemental analyzer. Thiol modified cellulose–gold nanoparticle composites served as active catalysts in the reduction of 4-nitrophenol into 4-aminophenol.

Here we report the first ever fabrication of metal/semiconductor Cd/CdO shelled hollow microspheres with average diameter of 20–30 μm via heating cadmium metal powder inside horizontal tube furnace at 500 °C for 40 min under ammonia gas flow of 150 sccm. Vapor-solid (VS) based growth mechanism was proposed for the formation of Cd/CdO shelled hollow microspheres (CCOSHMs). The as-prepared product was characterized using X-ray diffraction (XRD) and scanning electron microscopy (SEM). Room temperature photoluminescence (PL) studies exhibited a UV emission band at 395 nm (E = 3.13 eV) which may be ascribed to combined effect of near band edge emission of CdO and Cd related radiative recombination of electrons in s, p conduction band near Fermi surface and the holes in the d bands generated by Xe light excitation. The hydrogen absorption properties of CCOSHMs were investigated at three different temperatures 373, 473, and 573 K. The maximum hydrogen absorption of 1.30 wt% was observed at 573 K which is better than many other materials. This indicates the potential of Cd/CdO shelled hollow microspheres for applications in light emitting devices as well as an interesting material for hydrogen storage research.