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In this work, we report hybrid NiCo2S4@Ni(OH)2 electrode materials on Ni foam by a multi-step hydrothermal approach. The mass capacitance of the prepared sample shows an excellent cycling stability after 10 000 cycles of charge/discharge tests.

We prepare several Ni1−xCoxMoO4·nH2O nanostructures through facile hydrothermal strategies. The obtained electrode materials delivered a specific capacitance of 1390 F g−1 at 1 A g−1. The as-assembled device shows an energy density of 72.45 W h kg−1 at a power density of 2688.8 W kg−1.

We prepare hybrid structured NiCo2S4@PPy nanoarchitectures by a hydrothermal method and subsequent electrodeposition process. The assembled asymmetric device presents an energy density of 59.59 W h kg−1 at 1404.04 W kg−1.

Implementing sensitive and fast ppb-level formaldehyde sensing at room temperature is still in extreme demand for practical indoor air quality monitoring. Herein, we developed a visible-light-sensitive and dipole-modified graphene-based nanocomposite ZnOx@ANS-rGO for ultrasensitive trace formaldehyde sensing. The rich oxygen vacancy zinc oxide (ZnOx) nanoparticles on graphene nanosheets provide OH-groups and edge sorption sites to facilitate the activation of adsorbed oxygen. Moreover, the supramolecular assembled 5-aminonaphthalene-1-sulfonic acid-modified graphene (ANS-rGO) nanosheets with donor–π–acceptor dipole served as an excellent conduction platform to transport and collect photo-generated electrons. Based on the collaboration of rich ZnOx and ANS-rGO, the obtained sensor ZnOx@ANS-rGO-0.1 showed the highest response (Ra/Rg = 1.58 to 1 ppm HCHO) among the MOS materials reported so far, and its limit of detection (LOD) can be as low as 5 ppb under 405 nm light illumination at RT. The outstanding efficiency and accuracy of the obtained gas sensor were confirmed by practical performance estimation in a 30 m3 chamber. The selectivity, long-term stability, repeatability and humidity resistance of the obtained sensors at RT were also revealed. The sensing mechanism based on the combination of visible-light activation and dipole modification was analyzed by the O-XPS, PL, in situ ATR-FTIR and charge density difference calculation.

A tetraphenylethylene (TPE) derivative (N,N-dimethyl-N′-(4-(1,2,2-triphenylvinyl)phenyl)acetimidamide, TPE-amidine) was designed and synthesized, and used to prepare visible CO2 chemosensors, TPE-amidine-L (liquid) and TPE-amidine-S (solid). The hydrophilicity of TPE-amidine thoroughly changed because of the unique reversible reaction between the amidine group and CO2, which controlled the molecular aggregation extent in water by CO2. Combining with the well-known aggregate-induced emission effect, the highly selective CO2 chemosensor TPE-amidine-L was developed, which has the lowest CO2 detection limit of 24.6 ppm compared with other reported CO2 chemosensors, and can be regenerated within 10 s by adding triethylamine. With the aim of being safer and more convenient to use, a polyacrylamide hydrogel containing TPE-amidine was prepared as a renewable CO2 sensing “tape” (TPE-amidine-S). The flexibility, adhesivity, CO2 sensitivity and reversibility of the “tape” is systematically investigated, showing great potential for “on-site” and “real-time” CO2 detection in practical applications.

Molybdenum disulfide (MoS2) is an extremely promising electrode material for supercapacitors due to its superior electrochemical performance and conductivity. In this study, polypyrrole (PPy) modified MoS2/Ni3S2 (MNS@PPy) assemblies grown directly on the Ni foam (NF) substrate are prepared by a facile hydrothermal route and a subsequent electrodeposition process. The as-obtained products show a specific capacitance of 845 C g−1 at 1 A g−1 with outstanding cycling stability after 10 000 cycles. Using the as-synthesized products as positive materials, an assembled hybrid capacitor delivers an energy density of 280.5 W h kg−1 at a power density of 2845 W kg−1, demonstrating its promising application in portable micro-/nanoscale energy storage devices.

Herein, we report a simple and facile sequential hydrothermal process for the synthesis of Co3O4 nanowire@NiO nanosheet arrays (CNAs). The as-synthesized CNAs were characterized in detail using various analytical techniques, which confirmed the high crystallinity, purity, and high-density growth of these nanomaterials. From an application point of view, the as-synthesized CNAs were directly used as supercapacitor electrodes, revealing a specific capacitance of up to 2018 mF cm−2 at a current density of 2 mA cm−2. Furthermore, a flexible asymmetric supercapacitor was fabricated using the as-synthesized CNAs as the anode and activated carbon as the cathode, which revealed a specific capacitance of 134.6 mF cm−2 at a current density of 2 mA cm−2. In addition, the supercapacitor showed excellent capacity retention of 73.5% after 10 000 cycles at a current density of 10 mA cm−2.

The rational design and construction of supercapacitor electrode materials with prominent energy and power density play an indispensable role for their potential application in energy storage devices. In this work, NiCo2O4 nanowires grown on Ni foam have been synthesized through a facile hydrothermal approach, revealing a large capacitance and superior cycling stability with 80.3% capacitance retention after 20 000 cycles. The asymmetric supercapacitors are fabricated based on NiCo2O4 nanowire electrodes, which deliver an energy density of 27.4 W h kg−1 at a power density of 493.2 W kg−1 and an excellent cycle life with 79.2% capacitance retention after 10 000 cycles.

This paper reports the successful, eco-friendly and cost-effective synthesis of nanocuboidal-shaped zirconium based metal–organic framework (MOF), i.e., UiO-66, using poly(ethylene) terephthalate (PET) derived from 1,4-benzenedicarboxylic acid (BDC). BDC was synthesized from waste and post-consumed PET bottles via alkaline hydrolysis and it has been used as a source of organic linker. The synthesized MOF was characterized in detail in terms of its morphological, structural, compositional, thermal and textural properties with numerous analytical, spectroscopic and microscopic techniques. The detailed studies confirmed that the formed nanocuboidal-shaped UiO-66 showed high crystallinity, purity and porosity. The MOF was further investigated for the adsorption of non-steroidal anti-inflammatory drug, i.e., ketorolac tromethamine (KTC), from the aqueous phase. The effect of influencing parameters such as adsorbent dose, initial drug concentration and pH of drug solution was studied. It was found that the maximum adsorption capacity of the adsorbent (729.92 mg g−1) was achieved under acidic conditions (pH = 3). The adsorption phenomenon followed pseudo second order kinetics and the adsorption data of kinetics fitted well to the Langmuir isotherm model, demonstrating monolayer adsorption. The adsorbent also showed excellent stability and reusability up to six cycles as confirmed by the PXRD analysis. This study provides an efficient and eco-friendly strategy for the rapid removal of KTC from an aqueous solution, and may promote the ideal design of advanced MOFs adsorbents for environmental remediation.

This paper reports the synthesis of TiO2 quantum dots, carbon dots (C-dots), and TiO2/C-dots using facile sol–gel and hydrothermal methods. The synthesized quantum dots were further characterized in detail to understand their crystalline, structural, morphological, thermal and optical properties using various spectroscopic and analytical techniques. The characterization results confirmed that the prepared photocatalysts exhibited high crystallinity, purity and excellent optical properties. The morphological results indicated that the C-dots were uniformly distributed over the TiO2 quantum dots and nanocomposites have an average size of 12 nm. Furthermore, the prepared sample, i.e. TiO2/C-dots, was efficiently employed as a potential heterogeneous photocatalyst for solar light driven photocatalytic degradation of a fluoroquinolone antibiotic drug levofloxacin. To optimize the photocatalytic degradation experiments, various catalyst dose-dependent, pH-dependent, and initial drug-concentration dependent experiments were carried out. The photocatalytic experiments revealed almost complete photocatalytic degradation of levofloxacin (10 mg L−1) within 90 minutes of solar light illumination using the TiO2/C-dots under optimum conditions, whereas bare TiO2 showed only 66.5% degradation of the drug. Different commercial photocatalysts such as TiO2 PC-50 and TiO2 PC-500 were also used for comparing the photocatalytic efficiency of the synthesized photocatalyst. Furthermore, the stability of the photocatalyst was studied by performing recyclability experiments up to 5 cycles using the TiO2/C-dots, indicating that the nanocomposites could be reused without any significant loss. The TOC results indicated the simultaneous 53.4% mineralization and photocatalytic degradation of levofloxacin under optimized conditions. The enhanced photocatalytic activity of the nanocomposites was attributed to the presence of the C-dots in the system, which provided more active sites for the drug molecules and also restricted the recombination of charge carriers. The role of active radical species in the photocatalytic degradation of levofloxacin was also investigated. A photocatalytic degradation mechanism and pathway were also proposed.

Herein, we report the fabrication and detailed characterization of a new electrochemical enzyme-free sensor for the direct sensing of monosaccharide and disaccharide sugars based on perforated NiO nanosheets (NSs). The NiO nanosheets were synthesized by a facile hydrothermal process followed by annealing and they were characterized in terms of their morphological, structural, compositional and optical properties. Detailed characterization confirmed the large-scale synthesis, good crystallinity and high purity of the synthesized perforated NiO nanosheets. To fabricate sugar sensors, sensor electrodes were prepared by modifying carbon paste with the perforated NiO nanosheets. Cyclic voltammetry and amperometry techniques were used to investigate the effect of the NiO nanosheets on the electrocatalytic oxidation of monosaccharide and disaccharide sugars. The electrodes exhibit a high sensitivity to glucose (724 μA mM−1 cm−2), with a low detection limit (10 μM), and respond over a wide linear range (from 50 μM to 3 mM). The analytical performance of the developed sensors, in addition to their ease of fabrication, qualifies them to be a good platform for enzyme-free sugar sensing.

Mixed phased TiO2 catalysts codoped with N and Ti3+ have been successfully synthesized using a low-temperature, one step hydrothermal method using TiN as the precursor. The as prepared samples were studied for their crystalline structure, morphology, composition, and optical properties using various analytical techniques such as X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), ultraviolet-visible diffuse reflectance spectroscopy (UV-vis DRS), and X-ray photoelectron spectroscopy (XPS). It was observed that N and Ti3+ codoped TiO2 samples having mixed phases of brookite, anatase and rutile could be obtained at a wide range of hydrothermal time durations ranging from 24 h to 72 h. The as-prepared samples exhibit a distinct red shift, suggesting that N and Ti3+ codoping significantly enhances the optical absorption characteristics of TiO2. The photocatalytic activity of the prepared samples was studied using methylene blue and colorless resorcinol dyes. The prepared samples demonstrated good photocatalytic activity because of their excellent mixed phase crystalline structures and an increase in the threshold wavelength response. The mechanism of the photocatalytic degradation reaction was also studied. This work provides a novel strategy to fabricate and extend the visible light response of TiO2, which facilitates their application in the environment remediation and energy conversion.

The polyaniline (PANI)/epoxy nanocomposites with enhanced mechanical and electrical properties were prepared by three different techniques. Fourier transform infrared (FT-IR) spectroscopy and scanning electron microscopy (SEM) were used to study the chemical structure and surface morphology of the PANI nanoparticles, which were synthesized by the oxidation polymerization method. The effects of PANI loading and preparation method on the mechanical and electrical properties of PANI/epoxy nanocomposites were comparatively studied. The SEM images of the PANI/epoxy nanocomposites after doing the tensile test were used to study the dispersion of PANI nanoparticles in the epoxy matrix. The tensile strength of 5.0 wt% PANI/epoxy nanocomposites (107.27 MPa) was much higher than that of our previous PANI/epoxy nanocomposites (about 60.0 MPa) with the same PANI loading. The volume resistivity of the PANI/epoxy nanocomposites was also decreased compared to the reported literature. The toughness and Young's modulus of the PANI/epoxy nanocomposites were also studied and presented in this paper.

In this contribution, the synthesis and catalytic activity of alkali metal molybdates for the degradation of cationic dyes under ambient conditions were systematically studied. The influences of Na and Mo precursors, Na/Mo ratio, and calcination temperature on the chemical composition and catalytic activity of sodium molybdates were investigated. Among all the obtained sodium molybdates, Na2Mo2O7 showed the highest catalytic activity for the degradation of cationic red GTL, safranine T, and methylene blue, etc. Particularly for cationic red GTL, a degradation efficiency of 98.5% could be achieved within 5 min. The optimal synthesis conditions for the formation of pure Na2Mo2O7 are also presented. The morphology and structure of Na2Mo2O7 were carefully characterized using XRD, SEM, HR-TEM and SAED, and FT-IR. In addition to sodium molybdates, potassium and lithium molybdates were also similarly synthesized, which also showed excellent catalytic activities for dye degradation. This work will shed light on the synthesis of novel active catalysts for the catalytic wet air oxidation of dyes.

Bio-calcification, known as microbiologically induced calcium precipitation, is an important process of the global carbon cycle. A large number of microorganisms exhibit this ability, including cyanobacteria. Even though the process was realized a long time ago, the detailed mechanism is still unclear. In this paper, we investigate the key role of extracellular carbonic anhydrase during bio-calcification of Synechocystis sp. FACHB 898. Detailed studies revealed that the precipitation of CaCO3 was significantly hindered when the function of extracellular carbonic anhydrase in Synechocystis sp. was inhibited. Furthermore, the reduction of calcium concentration in solution was significantly correlated with the reduction of bicarbonate concentration as 1 : 2. The results suggested that extracellular carbonic anhydrase of cyanobacteria enhanced CaCO3 precipitation from calcium and bicarbonate through facilitating the proton consumption during transformation of bicarbonate to carbon dioxide.

Herein, we report the use of a layered double hydroxide/graphene oxide (LDH/GO) hybrid as a nanofiller for a polysulfone (PSf) substrate in the fabrication of a thin film nanocomposite (TFN) forward osmosis (FO) membrane. The influence of the incorporation of the LDH/GO hybrid on the physicochemical properties of the PSf substrate was explored and a systematic investigation of the resultant TFN membrane performance was conducted. The results demonstrate that the addition of the LDH/GO hybrid enhanced the PSf substrate with increased porosity, hydrophilicity, surface pore diameter, and mechanical strength. Consequently, all the TFN membranes obtained increased water permeability and salt rejection, as compared to the thin film composite (TFC) membrane prepared on a conventional PSf substrate. Using 1 M NaCl as the draw solution and DI water as the feed solution, the water flux of the TFN membrane with a 2 wt% LDH/GO dosage as high as 23.6 L m−2 h−1 was obtained under the pressure retarded osmosis (PRO) mode. Compared to conventional TFC membranes, the TFN membrane with a 2 wt% LDH/GO showed a very low reverse salt flux (6.2 g m−2 h−1). The improvement in FO performance is attributed to the lower structural parameters of the modified PSf substrate, and the reduction of the internal concentration polarization. This study suggests the LDH/GO hybrid is an effective additive for modifying the PSf substrate for the development of FO membranes.

Herein, we report the successful formation of graphitic carbon nitride coated titanium oxide nanotube array thin films (g-C3N4/TiO2) via the facile thermal treatment of anodized Ti sheets over melamine. The proportion of C3N4 and TiO2 in the composite can be adjusted by changing the initial addition mass of melamine. The as-prepared samples are characterized by several techniques in order to understand the morphological, structural, compositional and optical properties. UV-vis absorption studies exhibit a remarkable red shift for the g-C3N4/TiO2 thin films as compared to the pristine TiO2 nanotubes. Importantly, the prepared composites exhibit an enhanced photocurrent and photo-potential under both UV-vis and visible light irradiation. Moreover, the observed maximum photo-conversion efficiency of the prepared composites is 1.59 times higher than that of the pristine TiO2 nanotubes. The optical and electrochemical impedance spectra analysis reveals that the better photo-electrochemical performance of the g-C3N4/TiO2 nanotubes is mainly due to the wider light absorption and reduced impedance compared to the bare TiO2 nanotube electrode. The presented work demonstrates a facile and simple method to fabricate g-C3N4/TiO2 nanotubes and clearly revealed that the introduction of g-C3N4 is a new and innovative approach to improve the photocurrent and photo-potential efficiencies of TiO2.

Conjugated polymer (CP) multilayer films with higher conductivity have been constructed by electric-field induced LBL assembly technique. Single component has been selected in the alternate deposition process, which not only provides a universal approach for CP films fabrication but also broadens the applicable scope of LBL assembly technique.

In this contribution, the morphology-dependent performance of Mg3Al–CO3 layered double hydroxide (LDH) as a nanofiller for polypropylene (PP) was evaluated for the first time. Three types of PP nanocomposites with 0-dimensional spherical, 2-dimensional plate-like, and 3-dimensional flower-like Mg3Al–CO3 LDHs as nanofillers were prepared using a solvent mixing method. The influence of morphology as well as the loading of LDHs on the thermal stability, flame retardancy, and rheological behaviors of the PP/LDH nanocomposites was then systematically investigated. The results showed that the thermal stability was significantly improved after incorporating LDH nanoparticles. For instance, the T0.5 of the 13.0 wt% PP/plate-like LDH nanocomposite was increased by 61 °C compared to that of pure PP. The addition of Mg3Al–CO3 LDHs can enhance the flame retardant performance of PP as well, and the efficiency was dependent on both the morphology and loading of LDH. The influence on the storage modulus (G′) and loss modulus (G′′) of PP was observed to follow the order of spherical > plate-like > flower-like. This work demonstrated that more attention should be paid to the influence of LDH morphology for the future design of the polymer/LDH nanocomposites.

The increasing demand for high performance lithium ion batteries (LIBs) has aroused great interest in developing high specific capacity, cycle performance and rate capability anode materials. Transition metal oxides (TMOs) have attracted much attention as promising anode materials for rechargeable LIBs owing to their high theoretical capacity. Here, a general strategy has been developed to fabricate high-performance fibrous TMO anodes such as elemental Ni doped NiO fibre (NiO/Ni/C-F), yolk–shell structured carbon@Fe2O3 fibre (C@Fe2O3-F), and hollow CuO fibre (CuO-HF) with controllable nanostructures by using alginate microfibres as templates. The key to the formation of various TMO micro-/nano-structures is the templating ability of the natural structure of long alginate molecular chains, where the metal cations can be confined in an “egg-box” via coordination with negatively charged α-L-guluronate blocks. When tested as anode materials for LIB half cells, these fibrous electrodes deliver excellent cycling performance with no capacity decrease after 200 cycles (793 mA h g−1, NiO/Ni/C-F, 0.072 A g−1; 1035 mA h g−1, C@Fe2O3-F, 0.1 A g−1; 670 mA h g−1, CuO-HF, 0.067 A g−1), and demonstrate great rate performance at different current densities. This finding highlights a general, green and eco-friendly strategy for the scale-up production of potential high-performance TMO anodes for LIBs.

This paper reports a facile low temperature hydrothermal process to grow highly porous ZnO nanosheets, self-assembled in rosette-like morphology, over the transparent indium tin oxide (ITO) glass substrate for dye-sensitized solar cell application. The prepared porous nanosheets were examined in detail using several techniques to understand the morphological, structural, compositional, optical and photovoltaic properties. The detailed morphological investigations reveal that the prepared nanosheets are made by the accumulation of small ZnO nanoparticles with typical diameters of 28 ± 3 nm. A systematic growth process to prepare such ZnO nanosheets is also discussed in terms of chemical reactions involved. The prepared nanosheets possess the stoichiometric elemental ratios of Zn and oxygen and exhibiting good crystallinity and wurtzite hexagonal phase along with good optical properties. Furthermore, the prepared ZnO nanosheets on ITO substrates were directly utilized as a photo-anode to fabricate an efficient dye-sensitized solar cell (DSSC), which demonstrated a reasonable light-to-electricity conversion efficiency of ∼3.4% with high short circuit current (JSC) of 9.45 mA cm−2, open circuit voltage (VOC) of 0.654 and fill factor of 0.55. The obtained JSC and the performance of the fabricated DSSC are attributed to the high surface to volume ratio of porous ZnO nanosheets, which delivers the high light harvesting efficiency.

Heterostructured ZnO/ZnS nanoforests are prepared through a simple two-step thermal evaporation method at 650 °C and 1300 °C in a tube furnace under the flow of argon gas, respectively. A metal catalyst (Au) to form a binary alloy has been used in the process. The as-obtained ZnO/ZnS products are characterized by using a series of techniques, including scanning electron microscopy (SEM), X-ray diffraction (XRD), energy dispersion X-ray spectroscopy (EDS), Raman spectroscopy and photoluminescence. A possible growth mechanism is temporarily proposed. The hybrid structures are also directly functionalized as supercapacitor (SC) electrodes without using any ancillary materials such as carbon black or binder. Results show that the as-synthesized ZnO/ZnS heterostructures exhibit a greatly reduced ultraviolet emission and dramatically enhanced green emission compared to pure ZnO nanorods. The SCs data demonstrate high specific capacitance of 217 mF cm(-2) at 1 mA cm(-2) and excellent cyclic performance with 82% capacity retention after 2000 cycles at a current density of 2.0 mA cm(-2).

This work describes the facile aqueous solution based syntheses and detailed characterization of zinc based hydroxide/oxide and zinc hydroxy stannate materials and their efficient utilization as catalyst for the photodegradation of harmful organic dye, i.e. Rhodamine B. The detailed studies revealed that the reaction time and temperature are important parameters by which the crystal phases and morphology of prepared materials can be controlled. Therefore, it was observed that with increasing the reaction time and temperature, a mixed phase of Zn(OH)2 and ZnO and pure ZnO can be prepared. The detailed characterizations showed that zinc hydroxy stannate cubes grow in high density and possess cube shaped morphologies. The detailed photocatalytic experiments revealed that as-synthesized ZnSn(OH)6 cubes possess higher photoactivity compared to the zinc based hydroxide/oxide materials. The stability results indicated no significant deactivation even after four successive re-uses in RhB photodegradation. Furthermore, the rate of ˙OH radical formation during UV irradiation was also tracked to investigate the mechanism of RhB photodegradation. The same trend was also observed on comparing the photoactivity and rate of ˙OH radical formation. Thus, it can be proposed that the mechanism of RhB degradation catalyzed by the as-synthesized materials followed an indirect oxidation of the dye by ˙OH radicals formed over the photocatalyst during UV irradiation, instead of direct electron transfer between dye and photocatalyst because there was no remarkable adsorption of the dye onto the photocatalyst surface.

This paper presents the fabrication of a highly sensitive and selective glucose biosensor based on spruce branched α-Fe2O3 nanostructures. The spruce branched α-Fe2O3 nanostructures were synthesized by a hydrothermal process and characterized by using various techniques. The fabricated glucose biosensor exhibited a very high and reproducible sensitivity of 85.384 μA mM−1 cm−2 with a response time of less than 2 s and a detection limit (based on S/N ratio) of 1 μM. A linear dynamic range from 0.003–33 mM with a correlation coefficient (R2) of 0.9996 was observed for the fabricated biosensor.

This paper reports the photocatalytic degradation of levofloxacin (LEVO), a widely used antibiotic drug, using highly crystalline TiO2 nanoparticles. The TiO2 nanoparticles were synthesized using a sol–gel technique and characterized by various techniques in terms of their morphological, structural, compositional, thermal and optical properties. The detailed studies revealed that the prepared TiO2 nanoparticles are grown in high density, are highly crystalline and exhibit good optical properties. Over 90% photocatalytic degradation of LEVO was achieved by the prepared TiO2 nanoparticles in 120 min under UV light illumination. By comparing the photocatalytic degradation properties of the prepared TiO2 nanoparticles with a commercially available TiO2 catalyst (P25 and PC-50), it was observed that the as-synthesized TiO2 nanoparticles exhibited a superior photocatalytic performance towards LEVO. Moreover, the antibiotic efficacy of levofloxacin was tested against E. coli and interestingly, it was found that its antibacterial activity was drastically inhibited after the treatment of the drug solutions with the prepared photocatalyst.

This paper reports the successful fabrication and characterization of a highly sensitive p-nitrophenol (p-NP) amperometric chemical sensor based on crystalline α-MnO2 nanotubes. The α-MnO2 nanotubes were successfully synthesized using a simple hydrothermal treatment of potassium permanganate (KMnO4) and concentrated hydrochloric acid (HCl). The prepared nanotubes were examined in detail by using various analytical methods which revealed that the synthesized nanotubes are grown in very high density, possessing good crystallinity and high purity. The as-synthesized α-MnO2 nanotubes were used for the fabrication of the p-NP chemical sensor which exhibited high sensitivity of 19.18 mA mM−1 cm−2 and a low detection limit of 0.1 mM. To the best of our knowledge, this is the first report that used α-MnO2 nanotubes to fabricate a p-NP chemical sensor with such high sensitivity and low detection limit.

In this paper we report the preparation of a series of Bi3+-doped TiO2 nanoparticles with different Bi-concentrations, i.e. 0.25–5% by a facile sol–gel process and their application as an efficient photocatalyst. The detailed characterization revealed that the Bi-doped TiO2 catalysts possess densely grown nanoparticles, a high specific surface area, crystalline anatase TiO2 and good optical properties. The incorporation of Bi3+ into the TiO2 lattice led to the expansion of the TiO2 spectral response into the visible light region and the efficient separation of charge carriers. The prepared samples were employed for the photocatalytic degradation of Alizarin red S dye (ARS) under visible light illumination. It was found that the incorporation of the Bi3+ ions in the TiO2 lattice causes a marked improvement in the photocatalytic degradation of the ARS dye; however, the degradation efficiency depended upon the Bi+3 ion doping concentration and the dose of the prepared catalyst. The detailed photocatalytic experiments confirmed that the 1% Bi+3 ion doping concentration and 0.1 g L−1 dose exhibited the best photocatalytic degradation efficiencies for the model dye. Moreover, more than 80% degradation of ARS was observed by the prepared Bi-doped catalysts within 90 minutes under visible light. The synthesized Bi-doped TiO2 nanoparticles revealed a superior photocatalytic behavior towards the photocatalytic degradation of ARS under similar experimental conditions, as compared to the synthesized TiO2 nanoparticles and other commercially available derivatives (TiO2 PC-50 and TiO2 P25).

Using ZnO nanonails, a hydrazine electrochemical sensor has been fabricated, for the first time, which showed a high and reproducible sensitivity of 8.56 microA cm(-2) microM(-1) with a response time less than 5 s, a linear range from 0.1 to 1.2 microM and a correlation coefficient of R = 0.999. The limit of detection (LOD), based on the S/N ratio, was estimated to be 0.2 microM.

α-Fe2O3 dendritic nanostructures were prepared by simple hydrothermal method and then blended with MWCNT (multiwall carbon nanotubes) to construct a novel biosensor for the determination of L-dopa. The structure of the new material was characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM) and X-ray diffraction (XRD) and the electrochemical behavior of L-dopa was also studied by cyclic voltammetry (CV), differential pulse voltammetry (DPV) and amperometry in phosphate buffer solution (PBS) at pH 7.2. The experimental results suggested that α-Fe2O3 blended MWCNT composite showed 3-fold increase of the oxidation peak current compared to that of the bare electrode. The DPV current responses of L-dopa were increased linearly in the range from 5.0 × 10−8 to 3.8 × 10−6 M with a lower detection limit of 30 nM (3σ). Finally, the proposed sensor was demonstrated for the sensitive determination of L-dopa in pharmaceutical samples and the obtained results were quite promising.

We report the synthesis of coloured polypropylene (PP)/Mg 3Al-tartrazine layered double hydroxide (LDH) nanocomposites with enhanced thermal stability, UV absorption capacity, and rheological properties using a modified solvent mixing method for the first time. SEM images indicated that the LDH nanoparticles were evenly dispersed within the PP matrix due to the favourable interactions between PP and LDHs. TGA and DSC analysis indicated that the thermal stability of PP/LDH nanocomposites was significantly increased. Decreased G′ and G″ ascribed to the enhanced mobility (relaxation) of the confined polymer chains at the interface of the PP/LDH layers suggested that the LDH is nano-dispersed in the composites. UV-Vis spectroscopy showed that the addition of Mg3Al-tartrazine LDH significantly enhanced the UV absorption characteristics of PP. Since tartrazine is a nontoxic additive, these coloured PP/Mg3Al-tartrazine LDH nanocomposites are expected to have many promising applications such as for food packing and children's toys, etc. © 2013 The Royal Society of Chemistry.

In this contribution, polypropylene (PP) nanocomposites with four different inorganic anion (CO32−, NO3−, Cl−, and SO42−) intercalated Mg3Al layered double hydroxides (LDHs) as nanofillers were prepared using a solvent mixing method for the first time. The influence of interlayer inorganic anions on the thermal stability, melting and recrystallisation behavior and rheological property of PP was then systematically compared. The thermal stability was significantly improved, with Mg3Al–CO3 and Mg3Al–Cl LDHs, and T0.5 increased by about 44 °C compared to pure PP. The incorporation of LDHs increased the melting temperature (Tm) and the recrystallization temperature (Tc) of PP by about 3–4 °C and 10–13 °C, respectively. The influence on the storage modulus (G′) and loss modulus (G′′) follows the order of Mg3Al–SO4 > Mg3Al–NO3 > Mg3Al–CO3 > Mg3Al–Cl. Although the incorporation of all LDHs led to an improvement in the thermal stability, Tm, Tc, G′, G′′, and complex viscosity of PP/Mg3Al–X LDH nanocomposites, the extent of changes varied with the type of inter-layer anions. The study finally demonstrated that even very similar inorganic anions such as CO32−, NO3−, Cl−, and SO42− could lead to a significant difference in the property of the synthesized PP/LDH nanocomposites, and it must be taken into account for the future design of polymer/LDH nanocomposites.