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The present investigation aims to remove Cr(VI) by flower like Cerium Phosphate Polypyrrole nanocomposite material (CePO4-PPY). The material was synthesized by in situ oxidative polymerization method and characterized by FTIR, Raman, XRD, XPS, Zeta potential, N2 adsorption–desorption isotherms, and TGA-DTA analysis. Field emission scanning electron microscopy and transmission electron microscopy images revealed the flower-like morphology of the synthesized nanocomposite. Meanwhile, the fabrication of polypyrrole on cerium phosphate nanoparticles provided a plentiful of active adsorption sites to interact with hexavalent chromium ions. The Cr(VI) adsorption followed the pseudo-second-order kinetic and Langmuir isotherm model showing a high adsorption capacity of 117.78 mg g−1 at room temperature at lower pH. The high tolerance capacity of CePO4-PPY in the presence of other co-anions makes it a highly efficient adsorbent. The adsorption dynamic study demonstrated that the rate-determining step was controlled by surface diffusion, pore diffusion, and film diffusion. XPS spectra confirmed the simultaneous adsorption of Cr(VI) and in situ chemical reduction to Cr(III). Regeneration studies illustrated the efficiency of more than 80%, even after five cycles. Therefore, CePO4-PPY nanocomposite could be a unique alternative to act as a promising adsorbent for the effective treatment of Cr(VI) containing wastewater.

Wound dressings composed of hydroxyethylacryl chitosan (HC) and sodium alginate (SA) were developed with antibacterial activity by loading Ag particles. The formation of Ag particle in the HC/SA films was achieved by an immersion method through in situ chemical reduction of AgNO3 solution and confirmed by FTIR, SEM-EDS, XRD and XRF techniques. The effect of Ag loading in the Ca-crosslinked HC/SA films with different crosslinking density was studied on swelling behavior, mechanical properties, cytotoxicity, antibacterial activity and drug release behavior. The results showed that Ag loading increased swelling degree in phosphate buffer and enhanced mechanical properties. The HC/SA films with Ag loading exhibited antibacterial activity against E. coli and S. aureus as well as no toxicity on Vero cell. In vitro drug release profiles of the films were examined using para-acetylaminophenol, as a soluble model drug. The increase in crosslinking density and Ag loading prolonged drug releasing rate and almost the films showed linearity profiles. It can be concluded that the HC/SA films with Ag loading have a promising potential in modern wound dressings with antibacterial property and controlled drug release.

Novel PdAg bimetallic alloy nanoparticle modified graphitic carbon nitride (g-C3N4) nanosheet was designed and prepared by an in situ chemical reduction procedure. By optimizing the loading content of the PdAg alloy NPs, the PdAg/g-C3N4 composite photocatalyst showed a champion photocatalytic hydrogen generation rate of 3.43 mmol h−1 g−1, and the apparent quantum yield (AQY) was determined to be 8.43% at 420 nm. Moreover, the photoluminescence and photoelectrochemical experimental results suggest that a higher separation efficiency of photo-induced charge carriers (e- and h+) was obtained after loading PdAg alloy NPs on g-C3N4. The experimental outcomes indicate that there is a synergistic effect formed between PdAg and g-C3N4, which could significantly promote the charge transfer photo-induced charge carriers in the hybrid sample. A reasonable catalytic mechanism for the enhanced photocatalytic performance of the composite photocatalyst was proposed and verified by TRPL measurement, which could be taken as a guidance for the development of novel high performance catalytic system.

Here, by a simple one-step in situ chemical reduction method, the AgxCuy alloy was tailored on the surface of mesoporous TiO2 (M-TiO2), therefore, a series of bi-functional mesoporous TiO2 nanohybrids (M-TiO2/AgxCuy) for both surface enhanced Raman scattering (SERS) detection and photocatalytic degradation of ampicillin (AMP) were achieved. The composition and structure of the nanohybrids were well characterized using XRD, TEM, XPS and HRTEM-EDS measurements. Results indicated that AgxCuy alloy was mainly attached around the pores of M-TiO2 which may generate more active sites than nonporous P25−Ag−Cu. Thus, the M-TiO2/AgxCuy nanohybrids could be used as efficient SERS substrates to sensitively monitor the AMP in water with lower detection limit (˜ 1 ppt) than P25−Ag−Cu. Besides, the M-TiO2/Ag3Cu1 nanohybrid also showed higher photocatalytic activities for the degradation of AMP under UV irradiation over the M-TiO2/Ag, the M-TiO2/Cu and the P25−Ag−Cu. This work provided a simple and effective approach to synthesize bi-functional nanohybrids for detection and degradation of organic contaminants in wastewater.

International audience; The efficiency of zero-valent iron (Fe-0)for the degradation of contaminants in water or soil can be highly reduced by side reactions with oxygen or water. This work was conducted to test whether this drawback can be effectively suppressed by the carbonation of Fe-0 with pyrolyzed biomass, which forms a Fe3C composite. The composite Fe3C was characterized and its reactivity and stability were assessed in batch tests with methyl orange (MO) as a model pollutant. The results indicated that the removal rate of MO on Fe3C composite was higher than that of Fe-0 (7.587 mg/(g.min) vs. 4.306 mg/(g.min)) at pH 4, where the degradation mechanism was confirmed by high-performance liquid chromatography-mass spectrometry. More importantly, the produced iron oxide in the Fe3C composite was highly suppressed. Regeneration studies showed that after three times of cycling, the removal efficiency of MO on Fe3C composite was kept to 99.42%, but Fe-0 almost lost its reactivity. In situ chemical reduction of a colorimetric redox probe (indigo-5, 5'-disulfonate, I2S) quantitatively demonstrated that Fe3C composite has the reduction kinetics of I2S obviously slower than Fe-0, indicating that Fe3C composite improved the stability of incorporated Fe-0 to resist the side oxidation.

A series of Palladium (Pd) supported multi-walled carbon nanotubes (Pd/MWCNTs) were synthesized via modified impregnation of Pd2+ followed by in situ chemical reduction with ethanol, NaBH4, and H2 as the reducing agent (referred as Pd/MWCNTs-E, Pd/MWCNTs-B, and Pd/MWCNTs-H, respectively). The electrocatalytic hydrodechlorination of 4-chlorophenol (4-CP), a highly toxic, cancerigenic, and bio-refractory contaminant, was investigated in a three-dimensional electrochemical reactor with Pd/MWCNTs as the particle electrodes. Nearly 100% of 4-CP could be efficiently dechlorinated and completely converted into phenol within 30 min under optimized conditions. Transmission electron microscope (TEM) and X-ray diffraction (XRD) results indicated that the small Pd nano-particles (6.4–13.1 nm) were uniformly supported on the surface of MWCNTs and formed face centered cubic (fcc) structure in all as-prepared catalysts. The removal efficiency of 4-CP was significantly affected by the size of loaded Pd nano-particles, where Pd/MWCNTs-B (100%, 6.4 nm) > Pd/MWCNTs-E (60%, 9.5 nm) > Pd/MWCNTs-H (29%, 13.1 nm). Effects of current density, initial pH, and initial dissolution oxygen (DO) on the 4-CP removal were also investigated. Scavenger experiments confirmed that indirect reduction by atomic H∗ was responsible for the reductive dechlorination of 4-CP. The stability of Pd/MWCNTs-B for the 4-CP dechlorination was also exhibited in repetitive experimental cycles.

Pools of chloroethenes are more recalcitrant in the transition zone between aquifers and basal aquitards than those elsewhere in the aquifer. Although biodegradation of chloroethenes occur in this zone, it is a slow process and a remediation strategy is needed. The aim of this study was to demonstrate that combined strategy of biostimulation and in situ chemical reduction (ISCR) is more efficient than the two separated strategies. Four different microcosm experiments with sediment and groundwater of a selected field site where an aged perchloroethene (PCE)-pool exists at the bottom of a transition zone, were designed under i) natural conditions, ii) biostimulation with lactic acid, iii) in situ chemical reduction (ISCR) with zero valent iron (ZVI) and under iv) a combined strategy with lactic acid and ZVI. Biotic and abiotic dehalogenation, terminal electron acceptor processes and evolution of microbial communities were investigated for each experiment. The main results where: i) limited reductive dehalogenation of PCE occurs under sulfate-reducing conditions; ii) biostimulation with lactic acid promotes a more pronounced reductive dehalogenation of PCE in comparison under natural conditions, but resulted in an accumulation of cis-dichloroethene (cDCE); iii) ISCR with zero-valent iron (ZVI) facilitates a sustained dehalogenation of PCE and its metabolites to non-halogenated products, however, the iv) combined strategy results in the fastest and sustained dehalogenation of PCE to non-halogenated products in comparison of all four set-ups. These findings suggest that biostimulation and ISCR with ZVI are the most suitable strategy for a complete reductive dehalogenation of PCE-pools in the transition zone.

In situ chemical reduction using commercial zero valent iron microparticles (ZVIm) resulted to be an efficient technique for the removal of recalcitrant and toxic chlorinated organic compounds (COCs) dissolved in groundwater. Groundwater was obtained from Bailin’s landfill (Sabinanigo, Spain), where liquid and solid wastes of an old lindane factory were uncontrollably dumped during decades. 28 COCs were identified and quantified by gas chromatographic analysis: five isomers of hexachlorocyclohexane (α, β, e, γ, δ-HCH), benzene, 10 chlorobenzenes and 12 cyclic non-aromatic organochlorine compounds (ΣCOCs = 93 mg L−1). Batch-wise and column experiments were carried out using soil and groundwater from the polluted landfill. It was found that the dechlorination rate increases with the chlorine content of the organic molecule. Non-aromatic COCs with high chlorine content (from 5 to 7 atoms), as well as HCHs, were very rapidly eliminated in the presence of ZVIm via dechloroelimination, while conversions from 60% to 80% were obtained for chlorobenzenes at the end of the treatment, the last ones, dechlorinated via hydrogenolysis. It has been proved that ZVIm appears as an efficient, stable and cost-effective treatment for COCs reduction and the results obtained in the laboratory can be used at full scale. Therefore it was concluded that ZVIm can be used for the on site treatment of the pumped groundwater and also, for the in situ treatment (as permeable reactive barriers (PRBs)) of the groundwater, leading to the complete degradation of the most toxic COCs, those with higher chlorine content, less aromaticity and lower vapor pressure.

Non-noble metal Cd nanoparticles, as an efficient cocatalyst, are successfully constructed onto the surface of hexagonal CdS nanorods (CdS NRs) for the photocatalytic hydrogen evolution reaction by a facile in situ chemical reduction approach based on a thermal treatment process. The in situ introduction of Cd can significantly improve the photocatalytic H2 production performance of CdS NRs in sodium sulfide and sodium sulfite aqueous solutions under visible light irradiation. The superior electrical conductivity of metallic Cd and the intimate interfacial contact between Cd and CdS NRs are suggested to account for the enhanced light absorption intensity, more efficient charge separation, and faster interfacial charge migration, resulting in the dramatically promoted photocatalytic H2 production activity. This work provides a new route for the in situ deposition of Cd nanoparticles onto CdS and other Cd-containing semiconductor photocatalysts with desired morphologies.

In the present work, a newly synthesized hybrid β-chitin/dicalcium phosphate anhydrous (DCPA) loaded with copper nanoparticles Cu(NPs) was investigated as an antibacterial agent using various strains. The hybrid β-chitin/DCPA was obtained via a mechano-chemical route and the Cu(NPs) supported over β-chitin/DCPA matrix was successfully synthesized from Cu(II) ions using the ultrasound-assisted method followed by in situ chemical reduction with sodium borohydride. All the prepared materials were characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), UV–vis diffuse reflectance spectroscopy (DRS), simultaneous thermogravimetry/differential thermal analysis (TG/DTA), and scanning electron microscopy (SEM-EDS). The localized surface plasmon resonance (LSPR) of Cu(NPs) after the reduction process was identified by the optical absorption spectroscopy, in the visible light region around 600 nm. The antibacterial activity of Cu-based materials was investigated against series of Gram-positive bacteria (S. aureus, L. monocytogenes) and Gram-negative (E. coli, P. aeruginosa) strains, using the microtitration assay by determining the minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC). Among the materials tested, Cu(NPs)/β-chitin/DCPA exhibited a high antibacterial effect exceeding CuII-β-chitin/DCPA and many others reported antibacterial agents, with a MIC value of 125 μg.mL−1 (6 μg.mL−1 of copper). The excellent antibacterial result was related to high dispersion properties of the hybrid support (β-chitin/DCPA) which avoid the aggregation of Cu(NPs) via various surface bonds with β-chitin biopolymer. Copper-based materials synthesized here exhibit promising antibacterial activities which can be explored in more details in others bacterial strains.

Amorphous semiconductors usually suffer from low photocatalysis efficiency due to the fast charge recombination rate. In this work, to activate the amorphous Bi2WO6, Bi2O3 and Bi particles were in sequence deposited over its surface via a facile in situ chemical reduction of amorphous Bi2WO6 by NaBH4 at room temperature. In the resultant ternary Bi/Bi2O3/Bi2WO6, the well-formed heterojunctions (i.e. Bi-Bi2O3 and Bi2O3-Bi2WO6) and the surface plasmon resonance effect of Bi both contribute to an increase in charge carrier concentration, an efficient e−/h+ separation and then an enhanced visible light photocatalytic performance. The molar ratio of Bi, Bi2O3 and Bi2WO6 in composite can be modulated by the dosage of NaBH4, and consequently the amount of each heterojunction (i.e. Bi/Bi2O3 or Bi2O3/Bi2WO6) as well as the intensity of SPR effect could be tuned. The photocatalytic NO removal test under visible light irradiation shows that BWO-0.8 (0.8 denotes the molar ratio of NaBH4 to Bi2WO6) presents a maximum NO removal efficiency of 55.4%, much higher than that of the pristine amorphous Bi2WO6 (10%). The enhanced activity can be attributed to the balanced SPR effect of Bi metal and the heterojunction effect, making their overall contribution maximized. The pathway study of photocatalytic NO oxidation by in situ FT-IR suggests that NO is converted to nitrates adsorbed over the catalyst surface. The present work could provide a new approach to activate the amorphous semiconductors for efficient visible light photocatalysis.

In this work, ultrasound assisted catalytic removal of Rhodamine B (RhB) dye has been carried out in the presence of reduced Graphene Oxide enveloped Copper Phthalocyanine nanotube (RGO-CuPc) for the first time. This RGO-CuPc nanocomposite has been synthesized by in situ chemical reduction of Graphene Oxide (GO) with CuPc tube. Then our as prepared composite and pristine CuPc tubes are well characterized by various spectroscopic techniques such as X-Ray Diffraction, UV–vis and microscopic techniques like FESEM, HRTEM etc. Electrochemical EIS measurement has also been carried out to investigate charge transfer mechanism. These results confirm the purity of the as prepared samples. Efficient sonocatalytic RhB dye removal upto ∼92.22% is achieved by RGO-CuPc composite within 100 min as compared to pristine CuPc tube (∼70%). A plausible reaction pathway towards dye removal is discussed in detail. Also degradation performance in the presence of enhancer and scavenger has been investigated.

In this work, graphene supported Pt (Pt/G) and NiPt nanoparticles (NiPt/G) were synthesized by in situ chemical reduction of graphene oxide, Ni+2 and Pt+4 ions. The structural investigation was performed by Fourier transform infrared (FT-IR) spectra, X-ray photoelectron spectroscopy (XPS), Brunauer, Emmett, and Teller (BET) analysis, Field emission scanning electron microscopy (FE-SEM), Energy-dispersive X-ray spectroscopy (EDX) and X-ray diffraction (XRD). The electrocatalytic activity of the Pt/G and PtNi/G catalysts toward BH4− oxidation in alkaline media was investigated by means of cyclic voltammetry (CV) and chronoamperometry (CA). The results showed that the catalytic activity of the PtNi/G catalyst toward NaBH4 electrooxidation was higher than that of Pt/G because of the synergistic effect between Pt and Ni. A direct borohydride-hydrogen peroxide fuel cell (DBHPFC) was fabricated using Pt/G (0.5 mg cm−2) as cathode catalyst and NiPt/G as anode catalyst. The maximum power density was 64.9 mW cm−2 at 60 °C, 1 M NaBH4 and 2 M H2O2 for anodic loading of 2 mg cm−2 and 60.4 mW cm−2 at 60 °C, 1 M NaBH4 and 2 M H2O2 for anodic loading of 1mg cm−2.

A flexible polyamide@Ag hybrid nanoarray film was fabricated as a highly sensitive and disposable SERS substrate for sensing label-free adenosine. Through the combination of silver nanoparticle (AgNP) self-assembly onto polyamide and in situ chemical reduction for further AgNP growth under specific conditions, a SERS-active metal “hat” with a large number of nanogaps was formed on the surface of the nanoarrays. This in situ chemical reduction step can overcome the size limitation of direct self-assembly of AgNPs onto the array. The resultant hybrid substrate possesses both a high degree of structural stability and an orderly spatial arrangement, which are beneficial for the uniform distribution of hotspots on the substrate. Additionally, its SERS performance was improved by more than an order of magnitude relative to that of the directly self-assembled PA@Ag substrate, and the detection limit for rhodamine 6G (R6G) could reach 10−14 M. Adenosine, a possible lung cancer biomarker, was detected with this substrate, and the limit of detection could reach 10−8 M. To further increase the detection limit, 4-mercaptophenylboronic acid-modified AgNPs were introduced to form Ag-adenosine-Ag molecular bridges via the boronate affinity technique. This strategy can ensure that adenosine is located in hotspots as a connecting medium. Subsequently, additional Raman hotspots were generated on the active Ag “hat” surface, thereby achieving a secondary enhancement of the adenosine signal with a detection limit as low as 9.83 × 10−10 M.

Porous polymer microspheres with interconnective open pores have attracted significant interest, owing to their unique properties as compared to those of traditional microspheres. However, developing a facile synthetic method to produce these unique particles remains a challenge. Herein, a method is proposed to produce highly porous polystyrene (PS) microspheres with interconnective open pores and a uniform size distribution, which were prepared by simply dispersing PS seed particles in an oil-in-water emulsion system. The morphological evolutions of the PS microspheres exposed to different types of oil-in-water emulsions were systematically investigated, and the relationship between the colloidal stability of the emulsions and the final structure of the PS microspheres was studied. Based on these results, the best oil-in-water system for synthesizing highly porous PS microspheres with interconnected open pores was found. The proposed synthetic method was demonstrated to offer significant advantages over previously developed techniques; it was simple, fast, and easy to process, and did not require special additives such as surfactants, complex techniques, etching processes to generate pores, and sophisticated equipment. Catalytic microreactors were fabricated by synthesizing mono- and bimetallic nanocrystals on the surface of the porous microspheres via in situ chemical reduction. When the microreactors were used as a heterogenous catalyst for the 4-nitrophenol (4-NP) reduction reaction by sodium borohydride (NaBH4), they exhibited extremely high catalytic activity and excellent recyclability. These results demonstrated that the highly porous microspheres have very high porosity, huge surface area per unit volume, and good chemical stability, indicating their great potentials as a supporting material for practical applications in catalysis.

For practical applications of graphene-based materials in flexible supercapacitors, a technological breakthrough is currently required to fabricate high-performance graphene paper by a facile method. Herein, highly conductive (∼6900 S m−1) graphene paper with loose multilayered structure is produced by a high-efficiency in-situ chemical reduction process, which assembles graphite oxide suspensions into film and simultaneously conducts chemical reduction. Graphene papers with different parameters (including different types and doses of reductants, different thicknesses and areas of films) are successfully fabricated through this in-situ chemical reduction method. Meanwhile, the influences of the graphene papers with different parameters upon the supercapacitor performance are systematically investigated. Flexible supercapacitor based on the graphene paper exhibits high areal capacitance (152.4 mF cm−2 at current density of 2.0 mA cm−2 in aqueous electrolyte), and excellent rate performance (88.7% retention at 8.0 mA cm−2). Furthermore, bracelet-shaped all-solid supercapacitor with fascinating cycling stability (96.6% retention after 10 000 cycles) and electrochemical stability (an almost negligible capacity loss under different bending states and 99.6% retention after 4000 bending cycles) is established by employing the graphene paper electrode material and polymer electrolyte.

We demonstrate a facile, single step, low temperature and energy efficient strategy for the synthesis of SnO2-reduced graphene oxide (RGO) nanocomposite where the crystallization of SnO2 nanoparticles and the reduction of graphene oxide takes place simultaneously by an in situ chemical reduction process. The electrochemical property of the SnO2-RGO composite prepared by using low concentrations of reducing agent shows better Li storage performance, good rate capability (378 mAh g−1 at 3200 mA g−1) and stable capacitance (522 mAh g−1 after 50 cycles). Increasing the reductant concentration lead to crystallization of high concentration of SnO2 nanoparticle aggregation and degrade the Li ion storage property.

Graphene paper has attracted considerable attention because of its impressive electrical and mechanical properties, which endow it with the great potential for applications in future flexible electronics. Therefore, developing a high-efficiency route to fabricate large-area and foldable graphene paper with good electrical and mechanical properties is quite necessary. In this work, a facile in-situ chemical reduction method for the preparation of graphene paper was successfully developed. The in-situ chemical reduction process involves simultaneous film formation and reduction, and the produced graphene paper has high integrity and good foldability. The thickness and area of graphene paper can also be readily regulated by adjusting the experimental parameters. Furthermore, the dissipation of reductant air stream (HI/CH3COOH air stream) can “push up” the graphene nanosheets to form a loose layered structure. This inside-out reduction process gives the produced graphene paper a sheet resistance as low as 17.8 Ω sq−1, verifying the advantages of this in-situ chemical reduction method. For the application of the obtained graphene paper, a flexible solid-state supercapacitor based on the graphene paper was fabricated, which had a device areal capacitance of 44 mF cm−2 (device volumetric capacitance of 858 mF cm−3) and excellent electrochemical stability.

Graphene based polymer composites have attracted considerable attention for both fundamental studies and practical applications. Fabricating polymer/reduced graphene oxide (rGO) composites via a readily mass-producible and environment-friendly technique is imperative for industry production. In this work, we tried to add various kinds of chemical reductants as “modifier” and study the possibility of in situ chemical reduction of graphene oxide (GO) during traditional thermoplastic processing of polymer and GO mixture. The thermal analysis and structural characterization revealed that among the 4 kinds reductants we investigated, hydroquinone (HQ) can effectively reduce GO during the commonly used melt-blending or twin-roller miller mixing processing. For an ethylene vinyl acetate copolymer (EVA) composite prepared by melt-blending of EVA and GO (95:5 in mass) at 100 °C, the heat of reduction corresponds to the remove of oxygen-containing groups on GO in the composite is 50.6 J/g. In contrast, the value for the composite with 5 wt% HQ is only 1.6 J/g. The significant decreased values of reduction heat suggested the effective reduction of GO due to the addition of HQ. Although the reducing ability of HQ is weak relatively, our work confirms that it is possible to chemically reduce GO during traditional processing of polymer materials, which is helpful to develop a large-scale producible, cost-effective and environment-friendly approach for the fabrication of polymer/rGO composites.

In this study, N-doped reduced graphene oxide/waterborne polyurethane (NRGO/WPU) composites were prepared by in situ chemical reduction of graphene oxide in an aqueous solution system. The morphology, structure, electrical conductivity, electromagnetic shielding, as well as thermal stability of the NRGO/WPU composites were characterized. The results show that simultaneous chemical reduction and N-doped functionalization of graphene oxide were achieved using diethylenetriamine as a reducing agent and N-doping agent. The introduction of NRGO could endow the WPU with quality electromagnetic interference shielding effectiveness (EMI SE). The composites with 12 wt% NRGO content exhibited the EMI SE of 28.3 dB at 9 GHz. Attributable to the uniform distribution of NRGO in the WPU matrix and its formed network structure, the NRGO/WPU composites had a better electrical conductivity compared with virgin WPU. TG and DTG indicated that the NRGO/WPU composites had a better thermal stability than virgin WPU.

Polymeric membranes enhanced by nanoparticles have received great attention over the past decade due to their abilities to meet the growing demand in addressing the global scarcity and pollution of water resources. Many efforts have been devoted to improve the membrane performance using this strategy, and to develop novel applications via molecular-level design for nanoparticle-polymer systems. Recent advances in applying in situ preparative techniques in polymeric membrane can potentially lead to new classes of nano-enhanced membranes for advanced water purification. Considering the increasing interest in this field related to the potential for controlling the dispersion and stability of nanoparticles, we review the progress of in situ preparative techniques for water purification. Categories of in situ preparative techniques are elaborated in detail, primarily focusing on the mechanism of the sol-gel process and in situ chemical reduction, which are considered as the most common applications of in situ preparative techniques. We also describe the effect of binding styles of nanoparticles ( in situ formation in the membrane matrix or on the membrane surface) on the structure-property relationship in nano-enhanced membranes, discussing recent applications of in situ formed metal nanoparticles, metal oxide nanoparticles, polymeric nanoparticles and other nanoparticles in water treatment. Finally, we suggest the antifouling mechanisms of in situ preparative techniques and give a further perspective for the next-generation nano-enhanced membranes. Further development of nano-enhanced membranes must go hand in hand with strict regulations for drinking water consumption and environmental safety.

In present study, heterojunctioned Bi2O3/BiOCl (BO/BOC) was synthesized via in situ chemical reduction and oxidation of BiOCl nanoplates. BiOCl was reduced to metallic Bi in KHB4 solution followed by oxidation in H2O2 solution to produce BO/BOC. The BO/BOC was supported over graphene sand composite and also on chitosan using wet impregnation method to report BO/BOC/GSC and BO/BOC/CT nanocomposite. The morphology and compositional characteristics of BO/BOC/GSC and BO/BOC/CT were investigated by FESEM, TEM, HRTEM, FTIR, XRD, EDX, RAMAN, BET and UV–visible diffuse reflectance spectral analysis. The photocatalytic activity of BO/BOC/GSC and BO/BOC/CT was performed for mineralization of ampicillin (AMP) and oxytetracycline (OTC) antibiotics under solar light. The adsorption process had significant effect on photodegradation of AMP and OTC. The adsorption of both OTC and AMP onto BO/BOC/GSC and BO/BOC/CT followed pseudo second order kinetics. Simultaneous adsorption and degradation process (A + P) resulted in higher degradation rate of investigated antibiotics. The applicability of power law model indicates the intricacies of mineralization process. During A + P process, OTC and AMP were mineralized to CO2·H2O, NO3− and SO42− ions. Both BO/BOC/GSC and BO/BOC/CT exhibited significant recycle efficiency.

Monodisperse silver nanoparticles (Ag NPs) were facilely loaded on the inner and outer surface of hierarchical wrinkled mesoporous silica (WMSs) via an in situ chemical reduction, and the antibacterial capacity of the obtained nanocomposite was investigated in detail. Typical sulfydryl-functionalized wrinkled mesoporous silica nanoparticle with radical pore channels was firstly prepared through sol-gel technique with cetyltrimethylammonium bromide (CTAB) as the templating surfactant. After sulfonation of the as-prepared WMSs, Ag(+) ions were then densely locked up on the inner and outer surface of WMSs via electrostatic interactions. Well distributed Ag NPs (ca. 3-5nm) on WMSs without any agglomeration were finally obtained via a simple in situ reduction reaction with sodium borohydride. Minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) test indicated that the obtained products can achieve durable and much better antibacterial performance both against Gram-negative bacterium Escherichia coli (E. coli) and Gram-positive bacterium Staphylococcus aureus (S. aureus) comparing to pure colloidal silver nanoparticles, which rendered them as favorable candidate for the development of effective antibacterial agents.

This work presents the first comparative study on syntheses, characterization, and applications of different clay/gold nanoparticle composites (clay/AuNPs) as acetylcholinesterase (AChE) carriers and modified-electrode materials to detect chlorpyrifos, an organophosphate pesticide. The selected based-clays were plate-like kaolinite (Kaol; 1:1 aluminum phyllosilicate), globular montmorillonite (Mt; 2:1 aluminum phyllosilicate), globular bentonite (Bent; 2:1 aluminum phyllosilicate), and fibrous sepiolite (Sep; 2:1 inverted ribbons of magnesium phyllosilicate). The clay/AuNPs were synthesized using in situ chemical reduction of the gold precursor with anchoring 3-aminopropyl triethoxysilane (APTES) on the clay surfaces. The studied materials were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), nitrogen adsorption/desorption, Fourier transformed infrared (FTIR) spectroscopy, thermogravimetric analyzer (TGA), zeta-potential analysis, and electrochemical impedance spectroscopy (EIS). Surface area, surface charges, and hydrophilic/hydrophobic nature of based-clays and the clay/AuNPs played major roles on AChE loading, residual activity, and sensor storage stability. The Mt/AuNPs was determined, among the studied clays, as the best supports for AChE loading and residual activities due to its high specific surface area and weak electrostatic interaction with the immobilized enzyme. Since apparent catalytic efficiencies kcatapp/KMappof the immobilized AChE in the four clay/AuNPs were found statistically similar, Mt/AuNPs which contained the highest enzyme loading was the favorite modified-electrode material. For chlorpyrifos detection, Kaol/AuNPs-based sensors resulted in the lowest detection limit, presumably due to the strong hydrophobic surface that helps to concentrate the nonpolar pesticide to the vicinity of the immobilized enzyme. Unfortunately, the highest electrostatic repulsion between the Kaol/AuNPs and AChE, and the dehydrated Kaol surface resulted in the lowest storage stability of the AChE pesticide sensors. Overall, Mt/AuNPs showed the highest potential as the AChE carrier and the modified electrode material for chlorpyrifos determination.

Nickel decorated electro-conducting melamine-formaldehyde resin (MFR) composites were prepared in two steps. In the first step micron-sized electro-conducting MFR/polyaniline (PAni) composite particles were prepared by in situ seeded chemical oxidative polymerization of aniline in presence of mesoporous MFR seed particles. Then surface of MFR/PAni composite particles were decorated/doped with Ni particles via in situ chemical reduction of Ni(II) salt. The size, chemical composition and magnetic properties of the prepared composite particles named as MFR/PAni/Ni were analyzed by scanning election microscope (SEM), transmission electron microscope (TEM), Brunauer–Emmett–Teller (BET) surface analysis, Fourier Transform IR (FTIR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), thermal gravimetric analyzer (TGA) and vibrating sample magnetometer (VSM). The results suggested that surface of MFR/PAni composite particles are best doped/decorated with Ni particles when MFR/PAni to Ni weight ratio was 1/0.1. An increase in Ni amount resulted in higher agglomeration and produced some free Ni particles. MFR/PAni/Ni composite particles possessed paramagnetic characteristics. The electrochemical/capacitive performance of MFR/PAni/Ni composite materials was evaluated by cyclic voltammetry (CV). Surface decoration/doping of MFR/PAni composite particles with increasing amount of Ni particles improved the specific capacitance value, suitable for application in supercapacitor.

In this work, PdNPs@ZnO-Co3O4 was synthesized via the facile oxidation treatment of bimetallic ZnCo-zeolitic-imidazolate-framework (ZnCo-ZIF) followed by in situ chemical reduction of PdNPs on the surface of the nanocrystals. After combined with MWCNTs, the PdNPs@ZnO-Co3O4-MWCNTs nanocomposites were formed, which were then exploited as novel electrode materials to construct the non-enzyme electrochemical sensors for high-sensitivity detection of tanshinol. Due to the high catalytic activity of multi-metallic PdNPs@ZnO-Co3O4, and the excellent charge transfer property between imidazole groups of the ligands in MOFs and MWCNTs, the obtained sensor exhibited high sensitivity for tanshinol detection under optimum experimental conditions. The sensor shows two well linear relationship between the current and tanshinol concentration in the range of 0.002–0.69 mM (R2 = 0.989) and 0.69–3.75 mM (R2 = 0.994) with the corresponding sensitivity of 59.16 μA mM−1 and 19.08 μA mM−1. And the limit of detection (LOD) was calculated to be 0.019 μM (S/N = 3). Furthermore, with the advantages of good repeatability, stability and selectivity, the fabricated sensor can be successfully applied to measurement of tanshinol in real medicinal liquids samples. Our results would accelerate the applications of MOFs in electrochemical field and provide insights into design of multifunctional non-enzyme sensing materials for various applications in biocatalysis, bioanalysis and drug testing.

In this study, graphene (GP) supported Co-Sn-B alloy were synthesized via in situ chemical reduction reactions for hydrogen generation (HG) from alkaline sodium borohydride (NaBH4). X-ray diffraction (XRD), high resolution transmission electron Microscopy (HRTEM) and X-ray photoelectron spectroscopy (XPS) were employed to verify the structure, morphology and the surface element composition of the alloy. Coupled plasma-atomic emission spectrometry (ICP-AES) were used to analyze the surface composition of the alloy. The effects of complexing agent addition, Co/Sn molar ratio, graphene loading on catalytic activity of the alloy were studied. The maximum hydrogen generation rate reached 11,272 mL min−1gCo−1 at 30 °C in 5 wt. % NaOH and 5 wt. % NaBH4 solution, which was three times higher than unsupported Co-B catalysts. The activation energy of the catalytic hydrolysis reaction of sodium borohydride was 39.57 kJ/mol, which is comparable to the noble metal catalysts.

The synthesis and use of ternary metal oxides/metal particles/carbon hybrids, especially 1D naowires composed of MGeO 3 /M/C hybrids for energy storage, remains very few reports. In this work, 1D Cu x GeO y /Cu/C NWs (x 3 NWs, the phase partially transformed to a mixture of crystalline Cu (∼70 nm) and amorphous Cu x GeO y NWs with carbon coating, but the nanowire-shaped morphology was maintained. Electrochemical measurements showed that the Cu x GeO y /Cu/C NWs exhibited a stable reversible capacity of ∼900 mA h g −1 after 100 cycles. Even at 800 mA g −1 , it also exhibited excellent high rate capacity of 350 mA h g −1 . The newly generated Cu x GeO y @Cu@CNWs exhibit enhanced cycle stability with high lithium-storage capability compared to that of the as-preparedCuGeO 3 NWs. (*) The in situ-synthesized Cu nanoparticles, amorphous state and carbon coating might play an important role in activating and enhancing the reversibility of the conversion reaction of Cu x GeO y . In addition, this effective synthetic method might provide the methodology for the development of other ternary metal oxides/metal particles/carbon hybrids materials for energy storage.

In this work, a fascinating hybrid based on Ag-Pd bimetallic nanoparticles-decorated graphene oxide (Ag-Pd/GO) has been successfully synthesized by a green and in situ chemical reduction strategy. The resultant hybrid was particularly characterized by scanning electron microscopy, transmission electron microscopy, energy dispersive X-ray spectroscopy, ultraviolet-visible spectroscopy and electrochemical techniques. The morphological results illustrate that Ag-Pd nanoparticles in microspheric appearances are highly dispersed and embedded on the GO layers, resulting in a rough surface and three-dimensional (3D) microstructure with a high Ag-Pd content in the matrix. The as-synthesized 3D Ag-Pd/GO hybrid displays distinctly enhanced electrocatalytic activity for the vanillin oxidation in comparison with that of the monometal-decorated GO, revealing a synergistic effect of the matrix GO and the doped bimetallic Ag-Pd. Therefore, the Ag-Pd/GO composite can be used as an enhanced electrochemical sensing platform for the sensitive determination of vanillin, and the fabricated sensor displays a wide detection range of 0.02–45 μmol dm−3, low detection limit of 5 nmol dm−3 and satisfactory recoveries between 98.8 % and 103.5 %. All the results demonstrate that the 3D hybrids integrated graphene with bimetallic nanoparticles are promising candidates for the development of high-performance electrochemical sensors.

In the present work chitosan–silver (CS/Ag) nanocomposites, either in the form of nanoparticles (AgNP) or as ionic dendritic structures (Ag + ), are synthesized by a simple and environmentally friendly in situ chemical reduction process. The antibacterial activity of the resulting nanocomposites in the form of films is studied against two bacteria, Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli . The relationship between electrical, structural and antibacterial properties of CS/AgNP and CS/Ag + nanocomposites are studied by transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction, and UV–Vis, impedance, infrared and X-ray photoelectron spectroscopies. The results demonstrate that in contrast to CS/Ag + ion films, the CS/AgNP composites films (average particle size less than 10 nm) showed a significantly higher antibacterial potency. The collective action of AgNP and Ag + ions facilitate the enhancement and synergetic antibacterial activity below certain critical concentration. The bactericide activity of both CS/AgNP and CS/Ag + ion composite films increases by increasing the concentration of Ag. The composites containing 1 wt.% of silver nanoparticles and about of 2 wt.% of silver ions exhibit a maximum antibacterial activity, which is close to their electrical percolation threshold. The concentration of AgNP and Ag + ions above the threshold level greatly diminish the antibacterial potential.

A copper nanostructures-graphene oxide (Cu/GO) hybrid as a new electrocatalyst for highly sensitive detection of 2-naphthol (2-NAP) was successfully synthesized by a one-pot and in situ chemical reduction approach. The characterization results reveal that the cubic Cu nanostructures are tightly attached onto the GO sheets in the resulting hybrid. A lower oxidation potential and a larger peak current were observed for the 2-NAP oxidation at the Cu/GO modified electrode, demonstrating the synergistic electrocatalysis from Cu nanostructures and GO sheets. Consequently, the Cu/GO hybrid exhibits a low detection limit (5.0 nM) and wide linear ranges (0.1–4.0 μM and 4.0–130.0 μM) when used as a sensing material for the sensitive detection of 2-NAP. Finally, the fabricated sensor was successfully applied in the detection of 2-NAP in real samples and satisfactory recoveries in the range of 99.3%–104.0% were achieved.

Two different routes were employed in order to deposit silver nanoparticles (nAg) on alumina porous substrates aiming to obtain antibacterial filtering elements for the disinfection of drinking water. Silver nanoparticles were deposited on 40 and 80 ppi ceramic foams by sputtering DC (direct current power supply) and in situ chemical reduction of silver nitrate (AgNO 3 ). The depositions were characterized through scanning electron microscopy (SEM) and X-ray diffraction (XRD). The influence of nAg deposition on permeability properties was analyzed and, in sequence, preliminary antibacterial analysis was carried out. Results indicate that: (i) the chemical reduction route resulted in homogeneously distributed nanoscaled particles; (ii) the deposition of nAg had no significant effect on permeability properties and (iii) the in situ chemical reduction filters were efficient against Escherichia coli ( E. coli ).

In recent years, graphene, two-dimensional closely packed honey-comb carbon lattice, has been attracting much attention in the field of electrochemistry due to its intrinsic properties and merits. Moreover, nickel has found extensive use in preparation of biosensors. In the present study, we applied a simple and straightforward approach for the development of nickel nanoparticle-graphene sheet (NiNP-GS) modified glassy carbon electrode (GCE) for nonenzymatic biosensor applications. The nanocomposites of NiNP-GS with various concentrations of nickel nanoparticles (NiNPs) synthesized through in situ chemical reduction procedure. In order to develop NiNP-GS modified GCE, 10 μl suspension of NiNP-GS dispersed in deionized water was dripped on GCE surface and dried for 24 h at room temperature. The nanocomposites have been characterized using scanning electron microscope (SEM) and X-ray diffraction (XRD). Additionally, the sensing performance was evaluated by cyclic voltammetry. Results clearly demonstrated that the as-synthesized NiNPs with diameters less than 100 nm were well uniformly distributed on the surface of graphene nanosheets on graphene sheets. The characterization data also demonstrated that the nanocomposite film had a large surface area and enhanced electron-transfer rate compared with only Ni nanoparticles, due to an efficient electrical network through NiNPs direct anchoring on the surface of graphene. Furthermore, the sensivity and reproducibility of prepared electrode were better than other nickel electrodes reported. The good analytical performance, low cost and simple fabrication procedure make this novel electrode material promising for the development of effective non-enzymatic glucose sensor.

The CdS flower-like nanomaterials (FLNMs) were synthesized by a facile hydrothermal method. With the help of the hydrophilic group on polyvinyl pyrrolidone molecules, the CdS FLNMs were decorated with Au nanoparticles (NPs) through in situ chemical reduction of HAuCl4. The hybrid CdS/Au FLNMs were investigated through surface-enhanced Raman scattering (SERS). It is found that they can detect crystal violet, Rhodamine B and malachite green as low as 1.0 × 10−8 M, 1.0 × 10−8 M, and 1.0 × 10-7 M respectively. In addition, the theoretical simulation was carried out by the discrete dipole approximation (DDA) method. It is found that the strong electric field of Au dimer and the coupling electric field between Au NPs and CdS FLNMs makes a significant improvement in SERS. Therefore, the hybrid CdS/Au FLNMs have a potential in applications such as detecting organics.

The reduced graphene oxide/carbon fiber paper (rGO/CFP) composites are synthesized by in situ chemical reduction method, and then Pd nanoparticles are supported on the rGO/CFP via an electrodeposition process to obtain a novel Pd/rGO/CFP cathode, which is used for bromate (BrO3-) electroreduction. Pd particles are fairly well dispersed on the rGO nanosheets with a mean size of 6.7 nm. With the Pd/rGO/CFP electrode, the removal efficiency of BrO3- is up to 98.7% within 60 min at -0.5 V; the BrO3- reduction follows pseudo-first-order kinetics with the rate constant of 0.105 min(-1), which is much higher than that of CFP, Pd/CFP or rGO/CFP electrode. The rate constant is largely increased from 0.001 to 0.105 min(-1) upon lowering the cathode potential from 0 to -0.5 V, and is slightly decreased at more negative potentials. At -0.5V, the reduction rate is significantly enhanced at low pH, while at -1.5V, the pH effect is reduced. Within the concentration of GO precursor from 0.5 to 2.0 mg/mL, the as-prepared Pd/rGO/CFP electrode exhibits high and stable electrocatalytic activity. The rGO sheets shorten the effective lengths for electron transfer in the electroreduction of H2O/H+ to produce atomic H* for the indirect reduction of BrO3- to Br-. Accordingly, a high removal efficiency can be achieved with the applied potential as low as 0.5 V, which is less negative than that for H-2 evolution. Due to the strong interaction between surface oxides of rGO and Pd, the high stability of the composite film electrode is exhibited. (C) 2014 Published by Elsevier B.V.

Here, we report the synthesis and characterization of a novel nanohybrid composed of mesoporous carbon and silver nanoparticles (MC/AgNPs) to use in amperometric sensing of hydrogen peroxide (H2O2). In this process, the MC was synthesized by using the mesoporous silica as a template and glucose as a carbon source. The AgNPs were produced by in situ chemical reduction of silver nitrate through glucose as a reducing and stabilizing agent in the presence of MC to give the desired MC/AgNPs nanohybrid. It was investigated by field emission scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and electrochemical measurements. The obtained nanohybrid was used to modify a glassy carbon electrode and to fabricate an amperometric sensor for H2O2 determination at a working potential of −200 mV vs. silver/silver chloride electrode in aqueous 0.1 M phosphate buffer solution (pH 7.0). The resulted sensor can detect H2O2 in the concentration range of 0.1–41 μM with a detection of limit 50 nM at a signal-to-noise ratio of 3.

Silver nanoparticles (AgNPs) were impregnated in amine functionalized mesoporous silica (NH2-SBA-15) particles, by in situ chemical reduction, for making a hydrogen peroxide (H2O2) sensor. AgNPs formed were isolated and well dispersed in hydrophilic NH2-SBA-15 at a loading of 17.2 wt.%, with mean particle diameter 4.5 nm and standard deviation 0.4 nm. AgNP impregnated NH2-SBA-15 was used as a modifier of glassy carbon electrode (GCE) for an enzyme-less amperometric sensor. It showed good electrocatalytic activity towards H2O2. Optimum composition of the modifier on the GCE surface (12.2 mu g Ag in AgNP-NH2-SBA-15/cm(2) surface area of GCE) resulted in a high sensitivity of 171.3 mu A cm(-2) mM(-1) and a wide linearity range (5.3-124.5 mM H2O2), due to the high loading of electrically conductive AgNPs in NH2-SBA-15 host. The sensor was selective to only H2O2, even in presence of high concentrations of both reducible and oxidizable interfering agents, like, sodium nitrate, sodium nitrite, urea, glucose or ascorbic acid. The response time was also less than 3 s. Therefore, it achieved the desirable sensor-characteristics, like linearity, sensitivity, selectivity and speed of response. Our results are better than other reported H2O2 sensors with impregnated AgNPs (in terms of linear range and sensitivity), compared to even those with good conducting hosts (like carbon nanotube, graphene oxide). Therefore, performance of any sensor can be improved by ensuring uniform dispersion of isolated NPs at a high loading, when impregnated in a hydrophilic host. (c) 2014 Elsevier B.V. All rights reserved.

Free-standing composite films based on graphene/polyaniline (PANI) nanostructure were synthesized for supercapacitor application. First, polyaniline nanospheres were prepared by microemulsion polymerization, followed by the incorporation of graphene oxide nanosheets by hierarchical organization. The cationic PANI nanospheres were attached to the anionic GO sheets by electrostatic interaction and hierarchical deposition of GO/PANI nanostructures on a membrane filter via targeted self-assembly. Subsequent in situ chemical reduction of GO using hydroiodic acid produced well-defined graphene/PANI nanostructures having interpenetrating network with 3D open structure. The in situ GO reduction enabled keeping the hierarchical organization intact. The flexible graphene/PANI film produced was tested as a supercapacitor electrode using voltammograms and Nyquist analysis. The electro-capacitance of the film (448 F/g) was enhanced by 60% through the synergistic combination of graphene and PANI nanostructures. About 81% capacity retention was achieved for the composite compared to 38% for PANI alone after subjecting the samples to 5000 cyclic operations.

The present work reports the mechanical improvement in Cu matrix composites reinforced with graphene nanosheets decorated with Ni nanoparticles (GNS–Ni) hybrids. The GNS–Ni hybrids were firstly synthesized by an in situ chemical reduction method and then incorporated into the Cu matrix to fabricate bulk GNS–Ni/Cu composites by spark plasma sintering. Benefiting from the unique characteristic of GNS–Ni hybrids, the GNS–Ni/Cu composites exhibited homogeneously dispersed GNSs and a strong GNS–Cu interface interaction, therefore leading to a 61% increase in Young׳s modulus (132 GPa) and a 94% improvement in yield strength (268 MPa) by addition of only 1.0 vol% GNSs. The GNS–Ni/Cu composites exhibited a load transfer mechanism as verified by a modified shear-lag model. Our study thus shows the potential for GNS–Ni hybrids to be successfully used as a reinforcing phase in metal matrix composites.

Electrically conductive graphene-filled polystyrene nanocomposites with well-organized three dimensional (3D) microstructures were simply prepared by electrostatic assembly integrated latex technology. First, positively charged polystyrene was synthesized via disperse polymerization in ethanol/water medium by using a cationic co-monomer, and then directly co-assembled with graphene oxide. Eventually, a honeycomb-like graphene 3D framework was embedded in polystyrene matrix after in situ chemical reduction and hot compression molding. Due to the 3D conductive pathway derived from graphene based network evidenced by morphology studies, the fabricated nanocomposites show excellent electrical properties, i.e. extremely low percolation threshold of 0.09 vol% and high saturated conductivity of 25.2 S/m at GNs content of 1.22 vol%.

A novel non-enzymatic electrochemical sensor device was fabricated for glucose detection based on nickel nanoparticles/graphene nanosheets (NiNPs/GNs) composites, which were synthesized through in situ chemical reduction procedure. The NiNPs/GNs composites modified electrode exhibited high electrocatalytic activity and good response toward the oxidation of glucose in alkaline solution, attributing to the synergistic effect of GNs and NiNPs. At detection potential of +0.5 V, the biosensor exhibited high sensitivity of 865 μA mM −1 cm −2 for glucose with a wide linear range from 5 μM to 550 μM as well as a low detection limit of 1.85 μM (at a signal-to-noise ratio(S/N) of 3). The good analytical performance, low cost and simple fabrication procedure make this novel electrode material promising for the development of effective non-enzymatic glucose sensor.

Nanoscale zero valent iron (nZVI) particles, prepared by an in situ chemical reduction method, were employed for 2,4-dichlorophenoxyacetic acid (2,4-D) hydrodechlorination combined with the electrochemical method using a palladium/nickel foam (Pd/Ni foam) electrode. The nZVI particles were characterized by X-ray diffraction and high-resolution transmission electron microscopy. Whereas the chemi-deposited catalytic electrode was further characterized using X-ray diffraction, scanning electron microscopy and Energy dispersive X-ray. More rapid hydrodechlorination rate was observed using synergistic technology and almost all of the 2,4-D were degraded in 4 h, which was 12.5% higher than that obtained in the independent electrochemistry system. Furthermore, the reaction mechanism was discussed in terms of the mutual effect between electrochemistry and nZVI. Both of the removal efficiency and the current efficiency depended on several factors including palladium loading, nZVI dosage and current density. Small amount of nZVI dosage not only effectively improved the efficiencies but also substantially reduced the processing cost. Palladium loading and current density had a greater effect on the efficiencies. Phenoxyacetic (PA), o- chlorophenoxyacetic acid ( o- CPA) and p- chlorophenoxyacetic acid ( p- CPA) have been identified as transformation products in reactive medium.

In order to improve the energy utilization efficiency during heat charging and discharging processes, thermal conductivity enhancement of polyethylene glycol (PEG)/SiO2 hybrid form-stable phase change material (PCM) was achieved by in situ Cu doping via in situ chemical reduction of CuSO4 through ultrasound-assisted sol–gel process. This method would be an important approach to develop novel hybrid form-stable PCM with high thermal conductivity due to the mild preparation conditions. The XPS result of this material showed that the valence state of copper in PEG6000/SiO2 PCM was mainly zero. The FTIR demonstrated that there was no new chemical bond between Cu, PEG6000 and SiO2. The thermal properties and thermal stability of the composite PCM were confirmed using DSC and TGA analyses. The phase change enthalpy of Cu/PEG/SiO2 PCM reached up to 110 J/g, and the thermal conductivity was 0.414 W/(m K) for 2.1 wt% Cu in PEG/SiO2, which was enhanced by 38.1% compared to pure PEG. The Cu/PEG/SiO2 hybrid material had excellent thermal stability and good form-stable performance.

In this paper, we report on the first preparation of well-defined SiO(2)-coated graphene oxide (GO) nanosheets (SiO(2)/GO) without prior GO functionalization by combining sonication with sol-gel technique. The functional SiO(2)/GO nanocomposites (F-SiO(2)/GO) obtained by surface functionalization with NH(2) group were subsequently employed as a support for loading Ag nanoparticles (AgNPs) to synthesize AgNP-decorated F-SiO(2)/GO nanosheets (AgNP/F-SiO(2)/GO) by two different routes: (1) direct adsorption of preformed, negatively charged AgNPs; (2) in situ chemical reduction of silver salts. The morphologies of these nanocomposites were characterized by transmission electron microscopy (TEM) and scanning electron microscopy (SEM). It is found that the resultant AgNP/F-SiO(2)/GO exhibits remarkable catalytic performance for H(2)O(2) reduction. This H(2)O(2) sensor has a fast amperometric response time of less than 2s. The linear range is estimated to be from 1×10(-4) M to 0.26 M (r=0.998) and the detection limit is estimated to be 4 × 10(-6) M at a signal-to-noise ratio of 3, respectively. We also fabricated a glucose biosensor by immobilizing glucose oxidase (GOD) into AgNP/F-SiO(2)/GO nanocomposite-modified glassy carbon electrode (GCE) for glucose detection. Our study demonstrates that the resultant glucose biosensor can be used for the glucose detection in human blood serum.

Formulation of stable aqueous graphene solution is attempted either through esterification of GO with PEG and subsequent reduction in covalent approach or in situ chemical reduction of aqueous GO solution in the presence of NH2–PEG–NH2 in noncovalent approach. While covalent approach produces insoluble graphite-like precipitation, noncovalent approach produces practically homogeneous reduced graphene solution for several months without any precipitate. Noncovalent interaction between NH2–PEG–NH2 and graphene is crucial for formulating fully reduced graphene solution with high stability. Various wet process such as spin-coating, ink-jet printing, and spraying can be directly utilized to formulate graphene-based electronic devices such as transparent electrode or anti-static coating without any additional reduction process which is necessary when insulating GO solution is used instead. Non-conducting NH2–PEG–NH2 can be simply removed from conducting graphene film by simple filtration and washing process to formulate pure graphene film because interaction between graphene and NH2–PEG–NH2 is not covalent. The initial surface resistance of graphene thin film with NH2–PEG–NH2 is in the range of 106 Ω/□ but it decreases to 104 Ω/□ after removing NH2–PEG–NH2.

A hybrid consisting of a highly ordered nanostructure of metallic Cu(0) nanoparticles embedded in a poly(2-hydroxyethyl methacrylate) (pHEMA) matrix was successfully synthesized by in situ photopolymerization, followed by in situ chemical reduction. The evolution of an ordered nanostructure of Cu(0) showing a nearly amorphous nature is discussed, and it is proposed that it is due to a coupling interaction between the Cu precursor and the unpaired O of the COOR group, associated with water molecules, among pHEMA molecules. The hybrids showed a negative surface charge and considerable improvement in blood compatibility compared to neat pHEMA and the widely used biomaterial polysulfonate.

Gold nanoparticles synthesized by in situ chemical reduction of HAuCl4 with the use of polyelectrolyte serve as reductant and stabilizer. At the same time, gold nanoparticles were observed self-assembly into dimer and trimer aggregates, which were evidenced by TEM. The nucleation and growth kinetics was characterized by in situ UV–vis experiment. A model was proposed to illustrate the formation mechanism.

Several Sn-coated MCMB (mesocarbon microbeads) graphite anode materials were prepared by microencapsulating nanosize Sn particles in MCMB. The nanosized tin particles are homogeneously dispersed in MCMB graphite matrix via electroless in situ chemical reduction. X-ray diffraction and EDS measurement confirms the presence of Sn in MCMB matrix. A systematic electrochemical testing has been performed on the Sn-coated MCMB graphite electrodes. The tin-coated MCMB graphite electrodes demonstrated an improvement in lithium storage capacity. The reaction process of lithium intercalation and de-intercalation in MCMB structure and lithium alloying with tin has been identified by cyclic voltammetry measurement. The micro-encapsulation of Sn in MCMB graphite can enhance the electrochemical properties of MCMB graphite anodes.