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Zinc imidazolate framework (ZIF-8) and titanium dioxide (TiO2) have been extensively studied as photocatalysts and have shown promising results. Herein we are reporting a composite of carbon-doped TiO2 (C-TiO2) and ZIF-8 for solar light harvested methylene blue degradation. Pure ZIF-8 is an ultraviolet entity with a wide band gap energy of 4.9 eV due to which the analysis of its visible light assisted photocatalytic performance is a challenging task. C-TiO2 has been chosen owing to its low band gap energy as compared to TiO2 which enables the free radical initiated reaction to shift in the visible region instead of the ultraviolet region. The doping of C-TiO2 in the ZIF-8 matrix accounts for the abatement in the band gap energy of the C-TiO2/ZIF-8 composite. Moreover, ZIF-8's large surface area makes it easier for pollutants to adhere to the catalyst's surface. To construct a C-TiO2/ZIF-8 heterostructure, the zinc based ZIF matrix has been built upon the exterior of C-TiO2 nanoparticles. UV-Vis-DRS spectroscopy confirmed the reduction in the band gap of the composite in contrast to ZIF-8. The XRD analysis revealed the reduction in the average d-spacing as well as the average crystallite size. Raman spectra analysis confirmed the blue shift in Zn-N stretching band. The prepared composite of ZIF-8 decorated on C-TiO2 showed an efficient capacity of solar light harvested degradation of methylene blue which follows pseudo first-order kinetics.

This work reports the synthesis of Au doped iron oxide nanoparticles by co-precipitation method using a cationic polymer as a stabilizer and subsequent coating with graphene oxide (GO) to form the catalytically enhanced GO/Au-Fe3O4 nanoparticles. The nanoparticles were characterized using Fourier Transform Infrared (FT-IR) spectroscopy and X-ray diffraction analysis. The analysis confirms the synthesis of iron oxide nanoparticles and successive coating of GO. The synthesized nanoparticles were used as a catalyst for the reduction of 4-nitrophenol to 4-aminophenol. The effect of temperature on the catalytic activity was studied and the kinetic parameters were calculated. The iron oxide nanoparticles were found to be effective and highly reusable due to their magnetic nature. These nanoparticles can be recovered with the help of a magnet and can be separated effortlessly from the reaction medium after the completion of the reaction.

One-dimensional nanostructures of titanium dioxide (TiO2) pay tremendous attention to photocatalysis. In this context, we present the consequence of bimetallic nanoparticles (Zn-Pd) on electrochemical and photocatalytic properties of TiO2 nanotubes (TiNTs). Bimetallic nanoparticles of Zn-Pd are crafted on TiNTs by photodeposition process at room temperature. The presence of bimetallic nanoparticles (MNPs) decreases the ability of the recollection of the electron-hole pairs and modifies structure of TiNTs. Crafting of Zn-Pd on TiNTs modify the structure of ZnPd-TiNTs as evident by scanning electron microscopy (SEM). The results showed that nanoparticles of Zn-Pd are crafted uniformly over TiNTs. The detailed analysis of TiNTs and ZnPd-TiNTs are investigated via X-ray diffraction (XRD) and raman spectroscopy. Observations reveals intensity of plane increases after crafting of Zn-Pd, showing increased anatase phase crystallinity and crystallite size. In addition, the change in the peak position of ZnPd-TiNTs is due to the crafting of Zn-Pd over TiO2, resulting in a change in the TiO2 structure. The changed structure of TiNT extensively changes the catalytic properties of the hybrids of ZnPd-TiNTs that have been further corroborated by photocatalytic applications. The photocatalytic behavior of ZnPd-TiNT hybrids is found to be significantly higher than TiNTs. The enhancement in photocatalytic activity of ZnPd-TiNTs hybrids is owing to the better charge separation.

s Graphene oxide nanocomposites in polyethylene glycol (GO-PEG) were prepared by the ultrasonication assisted suspension. GO was synthesized by the modified Hummer’s method and was then dispersed in PEG to obtain the nanocomposites. The sonication time for the synthesis of the nanocomposites was varied to study its effect on the structural, optical and vibrational properties of the nanocomposites. The synthesized nanocomposites were characterized using UV–visible spectroscopy and Raman spectroscopy. The value of λmax for the synthesized nanocomposites was observed in the range of 230–250 nm. The D and G bands of carbon associated with GO were observed at 1360 cm−1 and 1588 cm−1, along with the 2D band in the micro-Raman spectrum of the GO-PEG nanocomposites.

One-dimensional (1D) titanium dioxide (TiO2) nanostructures have enormous attention for next-generation renewal energy resources. In reference to that, present work reports the effect of different voltages (40 V and 60 V) on the structural and morphological properties of 1D-TiO2 nanotubes (TONTs) and their hybrids by grafting of bimetallic nanoparticles (BiMNPs) of AgAu. The growth at different voltages affects the morphology and diameters of TONTs as imaged using field emission scanning electron microscopy (FESEM). The variation in anodization voltage from 40 to 60 V increases the diameter of TONTs that offers a larger active surface area of TONTs. It is further revealed that the crystallinity and crystallite size of TONTs is increased after increasing the anodization voltage. Furthermore, TONTs are integrated with AgAu BiMNPs to form the hybrid structures. The AgAu-TONT hybrid forms a modified interface and induces less compressive strains that improve the charge separation at the interface and hence improve the electronic structure, as investigated by X-ray photoelectron spectroscopy (XPS) and X-ray Diffraction (XRD). On further exploring the 1D-TONTs and AgAu-TONTs for photocatalytic studies, it is observed that the photocatalytic activity of AgAu-TONTs is better than TONTs-40 V and TONTs-60 V. The improved photocatalytic activity in the AgAu-TONTs is due to the large surface area, charge carrier generation, and lesser compressive strain present at the interface.

Metal oxide nanostructure hybrid materials have garnered focused attention for next-generation memory-based devices. TiO2 nanostructure hybrids dwell in that league of materials. In reference to th...

Phase change material (PCM)-based thermal energy storage (TES) systems are preferred due to high energy density; however, they possess an inherent problem of low dispatchability. This is due to the low thermal conductivity of the constituent PCMs. For ensuring high energy density and high rate of dispatchability of the TES systems, it is necessary to find methods to enhance the thermal conductivity of these PCMs. The present study chooses low-temperature melting PCM (n-nonadecane) which is suitable for thermal regulation of various devices, systems and buildings. For enhancement of PCM, TiO2 nanoparticles are prepared using continuous spray pyrolysis method and dispersed within the PCM matrix using advanced wet impregnation technique, to form nano-enhanced PCMs (NEPCMs). The thermal properties of these NEPCMs have been adjudged, in this study. The advanced wet impregnation technique ensures uniform mixing of nanoparticles, and no visual separation or settling issues are encountered up to 2% by weight concentration. An increase in thermal conductivity up to 37% is observed. It is also observed that beyond 2% concentration, partial settling of nanoparticles is observed over a 1-week duration.

In the quest to create effective sensors that operate at room temperature, consume less power and maintain their stability over time for detecting toxic gases in the environment, molybdenum disulfide (MoS2) and MoS2-based hybrids have emerged as potent materials. In this context, the current work describes the fabrication of Au-MoS2 hybrid gas sensor fabricated on gold interdigitated electrodes (GIEs) for sensing harmful CO and NH3 gases at room temperature. The GIEs-based Au-MoS2 hybrid sensors are fabricated by decorating MoS2 nanoflowers (MNF) with varying size of Au nanoparticles using an inert gas evaporation technique. It is observed that by varying the size of Au nanoparticles, the crystallinity gets modified, as confirmed by x-ray diffraction and Micro-Raman spectroscopy (μRS). The gas sensing measurements revealed that the best sensing response is found from the Au-MoS2 hybrid (with an average particle size of 10 nm). This particular hybrid shows a 79% response to CO exposure and a 69% response to NH3 exposure. The measurements are about 3.5 and 5 times higher than the bare MoS2 when exposed to CO and NH3 at room temperature, respectively. This enhancement in sensing response is attributed to the modified interfacial interaction between the Au nanoparticles and MNF gets improved, which leads to the formation of a Schottky barrier, as confirmed using x-ray photoelectron spectroscopy and ultraviolet photoelectron spectroscopy analysis. This enables the development of efficient gas sensors that respond quickly to changes in the gas around them.

Molybdenum Disulfide (MoS2) is considered as one of the most important two-dimensional (2D) transition metal dichalcogenides (TMDs), its atomic thin layer has a strong potential which is to be used as gas sensor components. In this paper a two-zone furnace is used to grow quasi two-dimensional (Q2D) thin layer of MoS2 on silicon dioxide substrate by varying zone temperature. Sulfur is placed in a boat upstream separated from the MoO3 boat, which contains substrate in face-down condition. Nitrogen (N2) is used as the carrier gas. Raman spectroscopy and X-Ray diffraction (XRD) is employed to study the crystal structure of MoS2. Furthermore, we have measured the effect of hydrogen (H) and carbon monoxide (CO) gas on the resistance of MoS2layered structure. These results improve our understanding of how the resistance of Q2D thin layer of MoS2 responds to CO gas.

Gold-Silver (Au-Ag) bimetallic alloy nanoparticles exhibit improved catalytic activity in comparison to the monometallic nanoparticles due to synergistic effect. In this work Au-Ag bimetallic alloy nanoparticles (BNPs) have been supported on alkali activated sand which acts as an inert support material, stabilizes the nanoparticles and prevents their agglomeration. In addition to providing high surface area for adsorption, sand is inexpensive and environmentally benign. Au-Ag alloy nanoparticles were prepared via co-reduction mechanism using polymer as a stabilising agent. Alkali activated sand was coated with the alloy nanoparticles using surface adsorption method. Efficient reduction of 4-Nitrophenol to 4-Aminophenol by NaBH4 in the presence of BNPs supported on alkali activated sand was investigated. Also, the heterogenous nature of the catalyst makes it highly reusable due to its effortless separation from the reaction medium.

Titanium dioxide (TiO2) is one of the most effective n-type semiconductors for photocatalytic applications. Compared with the bulk TiO2 nanostructures, the one-dimensional (1D) TiO2 nanostructures have elicited great interest due to its various advantageous properties such as high surface-volume ratio, high chemical stability, strong oxidizing power, nontoxicity and low cost. TiO2 exists mainly in two crystalline phases namely anatase and rutile. When different phases of TiO2 are combined, they have better charge transport and light absorption properties than pristine nanotubes and nanorods. In reference to that, mixed phases play an important role in the modification of the photocatalytic properties. In the present work, three different nanostructures (TiO2 nanotubes, nanorods and mixed phase nanohybrids) are fabricated by electrochemical anodization and hydrothermal processes, respectively. TiO2 nanotubes are synthesized by electrochemical anodization of highly pure titanium foil in a solution containing ethylene glycol, ammonium fluoride and distilled water, TiO2 nanorods are grown on fluorine-doped tin oxide (FTO) using a hydrothermal method and hybrid TiO2 nanostructures consisting of rutile TiO2 nanorods synthesized by hydrothermal method on anodized TiO2 nanotubes in a high temperature and high-pressure condition with titanium-n-butoxide as the reaction precursor. The three different morphologies of nanotubes, nanorods and nanohybrids are investigated using scanning electron microscopy (SEM). The crystallinity of the TiO2 nanotubes, nanorods and nanohybrids are studied using Raman spectroscopy and X-ray diffraction (XRD) techniques. TiO2 nanotubes, nanorods and nanohybrids are crystalized in anatase, rutile and mixed phase (anatase and rutile), respectively. The structural transformation of the formed TiO2 nanohybrid is compared with TiO2 nanorods and nanotubes that further be explored for photocatalysis by degradation of methylene blue (10 μM) under xenon lamp in the presence of catalysts. It is observed that overall photocatalytic activity of mixed phase TiO2 nanohybrids is better than TiO2 nanotubes and nanorods owing to better electron hole separation and transportation.

A novel pore-filling system was prepared using spray as the key-technique, for solar cells and various other applications. High performance in perovskite, dye-sensitized and eta cells is often achieved using metal oxide layers or their mesoporous analogues. One dimensional scaffold materials such as nanorods or nanotubes are also employed in order to improve charge collection. Herein, we introduce a method to more efficiently fill the pores in the most common nanostructure architecture namely mesoporous, nanorods or nanotubes. The method employs the use of spray technique with applied DC voltage (through two different voltage supplies) as the cost-effective technology for time efficient pore filling. SnS nanoparticles and N719 dye have been pore-filled onto a previously deposited ZnO nanorods and mesoporous TiO2 film, respectively, using the novel setup. Scanning electron microscopy images revealed an improved pore-filling, the complementary enhancement of ~ 24% in the DSSC efficiency and ~ 16% and 7% in terms of current density and fill factor, respectively has been found in comparison to the reference standard device. It is attributed to an increase in the concentration of dye molecules into the pores of TiO2 nanostructures due to better dye loading and hence observed an improvement in light absorption, electron transportation and charge collection. This pioneer pore filling technique exponentially reduced the dye loading time duration from overnight immersion of photo anodes in dye solution to 15–20 min.

Two-dimensional (2D)/one dimensionsal (1D)-MoS2/TiO2 heterostructures have proven to be potent for photocatalytic applications. Enhancement of a heterostructure’s photocatalytic activity may be influenced by the accumulation of strain at the interface, which affects the interfacial interaction. Keeping this in mind, the present paper reports strain-accumulated interfacial modification of 2D/1D-MoS2/TiO2 heterostructures for the enhancement of photocatalytic activity. Two different synthesis methods, namely the hydrothermal and chemical vapor deposition (CVD) methods, are used for the growth of MoS2 on TiO2 nanostructures. Micro-Raman spectroscopy reveals that strain is accumulated at the interface of the growth of the MoS2 over the TiO2 nanostructures. It is further revealed that the MoS2/TiO2 heterostructure synthesized by the CVD method induces compressive strain. Also, the heterostructure synthesized by the hydrothermal method induces tensile strain that modifies the charge separation at the interface, which is further confirmed by x-ray photoelectron spectroscopy (XPS). Moreover, ultraviolet photoelectron spectroscopy (UPS) reveals upward band-bending in the MoS2/TiO2 heterostructure synthesized by the hydrothermal method. Similarly, the heterostructure synthesized by the CVD method shows downward band-bending that leads to improved charge separation at the interface. The modified interfaces of the heterostructures are further studied for electrochemical measurements using cyclic voltammetry (CV) and photocatalytic activity by degradation of a model compound.

In this work, Boron Nitride (BN) nano-particles have been synthesized by hydrothermal treatment using boric acid and an amine-based nitrogen source. BN, a structural analogue of carbon, has garnered considerable attention in the recent years due to its high thermal conductivity, chemical stability, low toxicity, large intrinsic band gap and chemical inertness. The synthesized nanoparticles are non-toxic and heavy metal free exhibiting strong blue fluorescence under UV illumination. The BN nanoparticles were characterized by Transmission Electron Microscopy (TEM), UV–Vis Spectroscopy and Fourier Transform Infrared Spectroscopy (FT-IR) and Zeta Potential measurement. FT-IR analysis revealed the formation of B–N, O–H and N–H bonds. In case of UV–Vis spectroscopy, absorption wavelength was observed at 264 nm. The synthesized nanoparticles may have potential applications in the field of fluorescence sensing and bio-imaging.

Surfactant free MoO3 nanorods (50 nm–5 µm long and 50–300 nm diameter) with Au nanoparticles with varying nanorod dimensions and Au fraction have been synthesized in-situ by using inexpensive continuous spray pyrolysis (CoSP) technique. In-situ grown gold nanoparticles (∼10–20 nm) with MoO3 nanorods (Au/MoO3) were obtained which proved useful in getting the additional effect due to plasmonics. The CoSP- synthesized Au/MoO3 nanorods have been used as anode buffer layers in organic photovoltaic devices (OPVs). The resulting devices exhibit a remarkable enhancement in power conversion efficiency (from 2.22% to 3.71%) when Au/MoO3 nanorods were used in the device which can be attributed to the strong localized surface plasmon resonance (LSPR) absorption.

ZnO nanostructured thin films have been fabricated by continuous spray pyrolysis (CoSP) technique using different seed layers and implemented as photoanodes for photoelectrochemical (PEC) water splitting. Effects of Al loading (0.02–0.2 wt%) in the ZnO seed and the voltage applied during the spray on morphological, structural, optical and photoelectrochemical properties of ZnO nanostructures have been studied. In the ZnO films grown on Al doped ZnO(AZO) seed with lower Al wt%, a red shift in the band gap has been observed along with increased (0 0 2) orientation in the XRD pattern. A blue shift in band gap is observed with AZO seed having higher Al wt% which can be attributed to the Burstein-Moss effect. The decrease in the band gap with stronger (0 0 2) orientation becomes more prominent on applying the voltage. Linear sweep voltammetry measurements carried out on the ZnO films grown on AZO seed and with applied voltage show a significant increase in photocurrent under illumination as compared to that for unmodified ZnO thin films. The significantly improved photoresponse of ZnO nanostructured thin films using a simple and cost effective fabrication method can find applications for water splitting under light leading to hydrogen generation and other related products.

A simple, single pot synthesis method has been described for the synthesis of Au Ag alloy nanoparticles using cationic long chain polymer. Unlike other methods for alloy NP synthesis, our method is unique because of its fast synthesis rate and robust nature. The high stability of the synthesized monometallic and bimetallic nanoparticles is attributed to the combined effect of the steric hindrance and electrostatic repulsion provided by polymeric stabilizer. Efficient reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) in the presence of alloy nanoparticles and NaBH4 is investigated and is found to depend upon the gold content in the nanoparticles.

The synthesis of MoO3 nanoparticles is reported using a Continuous Spray Pyrolysis (CoSP) reactor and the influence of zone temperature, precursor concentration on the structural and morphological properties is investigated. The collected nanoparticles are utilized to prepare thin films by spin coating and further annealing at various temperatures. The improvement in morphology, crystallinity and the band gap shift shows the effectiveness of the annealing treatment in creating a proper hole transport layer for device applications. The technique thus allows the film formation using a non-vacuum method well suited for organic solar cells. The CoSP based MoO3 (CoSP_MoO3) films are demonstrated to have equal performance to hole-injection layers composed of thermally evaporated MoO3 (eMoO3).

One dimensional TiO2 nanorods (TONRs) hybrids have enormous potential for photocatalytic applications. Integrating TONRs with plasmonic Nanoparticles (PNPs) to form hybrid structures enhances its photocatalytic activity by local surface plasmonic resonance (LSPR) effect. The Present work reports PNPs decorated TONRs for visible light driven photocatalytic activity. PNPs of silver (Ag) and gold (Au) with different sizes are decorated over TONRs to form PNP-TONRs hybrids. The size of Ag and Au PNPs are engineered by using inert gas evaporation method at different vapour pressures. The microRaman studies of hybrids reveal the enhanced Eg mode due to SERS effect. The decoration of Au PNPs with small size PNPs on TONRs have been found efficacious to alter Schottky effect and plasmonic activity. PNPs-TONRs hybrids are further explored for photocatalytic activity. The overall photocatalytic activity of small sized Au based hybrids is better than Ag based hybrids owing to their better Schottky effect and plasmonic activity.

Diabetic wounds are susceptible to microbial infection. The treatment of these wounds requires a higher payload of growth factors. With this in mind, the strategy for this study was to utilize a novel payload comprising of Eudragit RL/RS 100 nanofibers carrying the bacterial inhibitor gentamicin sulfate (GS) in concert with recombinant human epidermal growth factor (rhEGF); an accelerator of wound healing. GS containing Eudragit was electrospun to yield nanofiber scaffolds, which were further modified by covalent immobilization of rhEGF to their surface. This novel fabricated nanoscaffold was characterized using scanning electron microscopy, Fourier transform infrared spectroscopy, and X-ray diffraction. The thermal behavior of the nanoscaffold was determined using thermogravimetric analysis and differential scanning calorimetry. In the in vitro antibacterial assays, the nanoscaffolds exhibited comparable antibacterial activity to pure gentemicin powder. In vivo work using female C57/BL6 mice, the nanoscaffolds induced faster wound healing activity in dorsal wounds compared to the control. The paradigm in this study presents a robust in vivo model to enhance the applicability of drug delivery systems in wound healing applications. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 641-651, 2018.

Any object on the earth’s surface having its temperature around 28°C acts as a strong source of thermal infrared radiation emitting mostly in 3–30 μM range. Thus, such objects become a source of infrared radiation with emission range overlapping with solar spectra. This overlapping is more significant in the 3–5 μM range. As the temperature of the object increases, the reflection of the solar radiation becomes less important than the self-emitted energy of the object. Since the emission from the heated objects and solar radiations has different overlapping mechanisms in different wavelength bands, the regulation of these radiations will also require different coating materials. Infrared reflective and absorptive materials are being used extensively in architectural, plastic, paints and military, photovoltaic, electronic, textiles, energy savings, etc. This chapter describes the mechanism of infrared radiation regulation by various organic and inorganic materials and their applications as active, passive, and opaque coatings.

Our primary source of clean, abundant energy is the sun; the sun deposits 120,000 TW of radiation on the surface of the Earth, far exceeding human needs even in the most aggressive energy demand scenarios. All routes for utilizing solar energy exploit the functional steps of capture, conversion, and storage. The sun’s energy arrives on earth as radiation distributed across the color spectrum from infrared to ultraviolet having wavelength in the range from 2.5 to 0.28 μm. The energy of this radiation must be captured as excited electron-hole pairs in a semiconductor, a dye, or a chromophore, or as heat in a thermal storage medium. This chapter describes the different ways of utilizing the energy coming from the solar radiation, which has opened new avenues for generating clean energy by solar energy conversion: solar electricity and solar thermal systems. To get the maximum efficiency of solar devices, it becomes important to tailor the properties of solar energy materials, that is, to maximize the usage of solar spectrum. One method of achieving the higher efficiency is to use the effect of nanoscale for enhancing photon management in the photovoltaic cell. The other way is to look for several ways of minimizing energy utilization, as conservation of energy is the most effective way of reducing CO2 concentration. It has been discussed that it can be achieved by using a unique class of materials called as Solar Energy Materials, for thermal applications, which have optical properties that make them well adapted for utilizing solar energy and for reaching energy efficiency, especially in the built environment.

Recent developments in the area of food technology revolves around nanobiotechnology. Nanostructured materials have numerous innovative and novel applications in the food industry. Owing to the availability of a broad combination of linkages between the food industry and nanobiotechnology, efforts have been made in extending the storage life, enhancing food security, improving flavor, and delivering active food ingredients. Nanomaterials allow better encapsulation and release efficiency of the active food ingredients compared with traditional encapsulating agents. Electrospun nanofibers are excellent materials for the development of structural matrix for artificial foods and ecofriendly food packaging material. This chapter presents the applications of electrospun nanofibers for the production of a plethora of bioactive food ingredients and the value addition of food products. In addition, an overview of nanofiber materials and fabrication techniques for nanofibers has been highlighted. Future developments could provide the technology to extend the scope of production of ingredients to the food industry and should aim to improve the potential applications of nanotechnology for functional foods and nutraceuticals. Novel concepts and engineering approaches should be involved in nanomaterials to target the delivery of bioactive compounds and micronutrients. Further, new insights need to be gained regarding the interactions of multiple food ingredients and the biosafety of such functional foods.

This work reports tuning of the band gap of the titanium dioxide (TiO2) nanoparticles by carbon doping during sol-gel synthesis. Herein, polydiallyldimethylammonium chloride (PDADMAC), a cationic polymer has been used as the carbon source. The band gap, microstructure and the phase of the synthesized TiO2 can be engineered by controlling the concentration of PDADMAC. A significant reduction in the band gap energy from 2.96 eV to 2.37 eV was observed upon carbon doping. Phonon Confinement Model was employed to investigate the material properties. Theoretical calculations based on Density Functional Theory have also suggested the reduction of band gap as a result of significant interaction between carbon, titanium and oxygen atoms in the lattice. These studies have also proved that structural modifications also occurred due to doping of carbon atom in TiO2 nanomaterial. Carbon-doping resulted in a more efficient photocatalytic activity of the TiO2 nanoparticles. The kinetics and thermodynamics of photodegradation of methylene blue was investigated in detail.

Different coloured TiO2 nanoparticles were fabricated by continuous spray pyrolysis (CoSP) technique due to the controlled manner of defects formation in large scale synthesis of black, green and white TiO2 with the creation of selective Ti3+ defects as well as defects correlated to oxygen vacancies. The enhancement in the zone temperatures in CoSP furnace is resulted changed in the color of TiO2 nanoparticles. The change in colour is also affected by the subsequent annealing of nanoparticles. The changes occur due to a controlled and selective growth of TiO2 nanostructures inside the CoSP furnace. Ti3+ defects creation in the nanoparticles/hollow microspheres seems to occur because of a high pressure created during the synthesis. XPS analysis revealed that the black colour of as-prepared TiO2 is due to the formation of high concentration of Ti3+ defect (peak at 456.84 eV), which is also confirmed by the electron paramagnetic resonance analysis.

Chronic wounds and ulcers are posing a devastating manifestation on the socioeconomic status across the globe along with the patient compliance. It reinforces a need for the development of successful alternative treatments for the chronic wound care and ulcer management practices. This review explores the progressive developments being made in the fabrication of electrospun nanofibrous scaffolds towards elimination of microbial infection from chronic wounds to accelerate the wound healing process. Functional three dimensional nanofibrous scaffolds produced by electrospinning have great potential in a wide spectrum of biomedical practices, such as tissue engineering, drug/gene delivery and wound dressing. Moreover, this review also highlights the materials and post modification methods, such as the functionaliation of electrospun nanofibrous scaffolds using growth factors, so that such smart and bioactive nanofibrous scaffolds could be made suitable for wound healing applications.

This manuscript focuses on the fabrication of metal–semiconductor (M–S) hybrid thin films using simple and cost-effective spray pyrolysis technique. Various host matrices were chosen to demonstrate the versatility of our technique. The absorption characteristics of in-situ grown noble metal nanoparticles into the various host matrices (CdS, ZnO, ZnS, PbS, CuInS 2 ) have been demonstrated. The brilliant colors of M–S films are because of the surface plasmon resonance (SPR) absorption governed by the metal nanoparticles size, shape, morphology and the dielectric constant of the host matrix. The SPR peak due to the gold (Au) domains was observed in the visible–NIR region (550–1000 nm) which can be tuned with Au loading in the host matrix. The structural and morphological characterizations were carried out using XRD and TEM that reveals the distinct phases of Au and host material. The in-situ growth mechanism of Au domains in the host matrix has been also described.

Nanomaterials have emerged over the past decade as promising commodities in many fields including cosmetics, environment, food and feed, healthcare, biomedical, optics, drug-gene delivery, health, mechanics and chemical industries. The food industry has also embraced the ‘nano’ era in response to a growing need by consumers for healthier and nutritionally appealing, cost effective products. The excellent future of ‘nanotechnology’ in the food industry has evoked food scientists to think innovatively to meet these demands. Applications of nanotechnology in food science are going to impact the vital aspects of food and related industries from food safety to the molecular synthesis of new food products and ingredients. Modern day nanosensors are being developed for improving food quality and safety and packaging techniques that will change the way food is stored and delivered.

The study presents dithiothreitol (DTT) functionalized anisotropic gold nanoparticles (GNP) based colorimetric sensor for detection of toxic lead ions in water. Our results demonstrate the selectivity and sensitivity of the developed sensor over various heavy metal ions with detection limit of ∼9 nM. The mechanism of sensing is explained on the basis of unique corona formation around the DTT functionalized anisotropic GNP.

Nitrogen-doped, PEGylated carbon dots (C-dots) have been synthesized for the detection of mercury ions (Hg(2+)). The detection limit was found to be 6.8 nM. However, upon functionalization with dithiothreitol (DTT), it reached to as low as 18 pM. The C-dots-Hg(2+) system was also able to efficiently detect biothiols.

Using lysine (Lys) and dithiothreitol (DTT) as aggregation promoters, an ultrasensitive and highly selective colorimetric assay for detection of mercury (Hg2+) ions has been developed with anisotropic gold nanoparticles (GNP). The detection limit of the assay is determined to be 27 pM and 58 pM for Hg2+ in deionized water and tap water, respectively. The mechanism of sensing is explained on the basis of possible mercury-gold amalgam formation and subsequent aggregation of the GNP upon addition of Lys and DTT. The kinetics data indicate that the sensor can be effectively used for on-site and real-time Hg2+ detection.

A novel synthetic approach has been used to prepare sorbent hydrogel composite beads of potassium nickel hexacyanoferrate (KNiHCF), using PVA and cross-linked alginate as the binding matrix. The characterization study indicates the high hydrophilicity and high surface area of the synthesized beads. The application potential of these beads for removal of cesium ions from low level liquid nuclear waste has been studied in batch mode using a 137Cs radiotracer. The equilibrium sorption and kinetic data are obtained at different initial cesium ion concentrations. These data are analysed using various sorption isotherm and kinetic models. It is observed that the sorption process can be best described by the Langmuir isotherm model, and the monolayer capacity of the beads is determined to be 7 mg per g of the swollen beads, which corresponds to ~64 mg per g of the dry beads. The sorption of cesium ions onto the sorbent beads is found to follow pseudo second-order kinetics over the entire studied concentration range. The ion-exchange mechanism involves the exchange of cesium ions with potassium ions. The mechanism of the sorption process is also investigated using the intraparticle diffusion model and Boyd's plot, and the results indicate that the sorption of cesium ions onto the beads is a complex process, involving both intraparticle diffusion and film diffusion.