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Recently, tetracyclines (TCs) have become the most used antibiotics in animal husbandry since they can kill most Gram-positive and -negative bacteria. However, it is still a tough problem to accurately detect residual TCs. Carbon dots (CDs) have attracted intensive attention owing to their excellent fluorescence performance, good biocompatibility and facile availability. Thus, many research studies have been conducted to fabricate high-performance CD fluorescent probes for the fast and accurate detection of TCs. Nevertheless, a comprehensive summary about the effective synthesis of CDs and their practical function in detecting TCs is still needed to further strengthen the wide application of CDs. We herein first give a detailed introduction of TCs and CDs. Then, based on the different synthetic technologies, the synthetic methods of CDs are divided into top-down and bottom-up strategies. In addition, from the different doped species, we classify CD fluorescent probes as undoped CDs, metal-doped CDs, nonmetal-doped CDs, co-doped CDs and CD nanocomposites. Furthermore, the remaining defects and prospects are highlighted to provide valuable guidance in preparing commendable CDs and detecting TCs. [ABSTRACT FROM AUTHOR]

Abstract: Novel composite catalysts have been fabricated by the electrodeposition of Pt onto the glassy carbon electrode (GC) modified respectively with polyindole (PIn) and poly(5-methoxyindole) (PMI) and used for the electrooxidation of methanol in acid solution of 0.5M H2SO4 containing 1.0M methanol. As-formed composite catalysts are characterized by SEM, XRD and the electrochemical methods. The results of the catalytic activity for methanol oxidation show that the two composite catalysts exhibit higher catalytic activity and stronger poisoning-tolerance than Pt/polypyrrole/GC (Pt/PPy/GC) and Pt/GC. Electrochemical impedance spectroscopy indicates that the methanol electrooxidation on the composite catalysts at various potentials shows different impedance behaviors. At the same time, the charge-transfer resistance for electrooxidation of methanol on Pt/PIn/GC and Pt/PMI/GC is smaller than those on Pt/PPy/GC and Pt/GC. The present study shows a promising choice of Pt/PIn and Pt/PMI as composite catalysts for methanol electrooxidation. [Copyright &y& Elsevier]

Abstract: Four novel composite catalysts have been developed by the electrodeposition of Pt onto glassy carbon electrode (GCE) modified with polyindoles: polyindole, poly(5-methoxyindole), poly(5-nitroindole) and poly(5-cyanoindole). As-formed composite catalysts are characterized by SEM, XRD and electrochemical analysis. Compared with Pt nanoparticles, respectively, deposited on the bare GCE and on the GCE modified with polypyrrole, the four newly developed composite catalysts exhibit higher catalytic activity towards formic acid electrooxidation by improving selectivity of the reaction via dehydrogenation pathway and thus mostly suppressing the generation of poisonous COads species. The enhanced performance is proposed to come from the synergetic effect between Pt and polyindoles and the increase of electrochemical active surface area (EASA) of Pt on polyindoles. [Copyright &y& Elsevier]

Abstract: Magnetic PtCo/Au nanocomposites with narrow size distribution were synthesized in a reverse micelle, followed by a post-synthesis handling of the stabilizer-exchange technique. The PtCo/Au nanocomposites were characterized by ultraviolet visible spectroscopy, X-ray diffraction and transmission electron microscopy, respectively. Superconducting quantum interference device studies revealed that the nanocomposites were superparamagnetic above the blocking temperature (T B=69K), while the samples were ferromagnetic with Hc (628Oe) and Ms (2.97emu/g) at 5K. [Copyright &y& Elsevier]

Abstract: Undoped and Mo(VI) ions doped TiO2 thin films were prepared via sol–gel method on different substrates. The morphology and the crystalline structures of the thin films were studied by SEM and XRD. The UV light inducing hydrophilicity was improved by doping Mo(VI) ions. The influence of the dopant density on the photo-induced superhydrophilicity of the films was investigated using cyclic voltammetry. A new oxidation peak was observed at about 0.17V when the TiO2 electrodes were irradiated by UV light for a certain time. The peak current increased with the irradiation time. To reach the same peak current, 0.75% Mo(VI) ions doped films required short time than the undoped film. [Copyright &y& Elsevier]

In this article, a new method which not only can separate hydrophobic Au nanoparticles (NPs), but also obtain highly monodisperse NPs is discussed. A self-made device of two same burettes, one of which was inserted into the other, was used for separating the nanoparticles by washing the reversal micelle. The effects of separation were characterized and analyzed by micrograph of transmission electron microscope (TEM), UV-vis spectra, quartz crystal microbalance (QCM), and energy dispersive x-ray analysis (EDX). It has been shown that, the smaller nanoparticles are, the easier they are to stay at the reversal micelle and the narrower the sizes are. This method can be applied to synthesize highly monodisperse Au NPs. [ABSTRACT FROM AUTHOR]

Abstract: The hydrophobic gold nanoparticles protected with octadecylamine, tetradecylamine and decylamine, respectively, were prepared by using ethanol reduction in reverse micelle through microwave dielectric heating. In this experiment, the commonly used toxic and highly volatile organic solvents such as chloroform, toluene and so on, which were an obstacle for preparing hydrophobic nanoparticles under microwave irradiation, were replaced by a safe organic mixed solvent n-heptane/ethanol used as an oil phase. The various alkylamine-stabilized gold nanoparticles obtained through this method were characterized and analyzed by ultraviolet visible spectroscopy (UV–vis), X-ray diffraction (XRD), transmission electron microscopy (TEM), thermogravimetric analysis (TGA) and elemental analysis. When the molar ratio of alkylamine to HAuCl4 was 40:1, the average diameters and standard deviations for octadecylamine-, tetradecylamine- and decylamine-capped gold nanoparticles were 4.53±0.79, 5.22±1.66, and 4.09±1.22 nm, respectively. Furthermore, the composition of octadecylamine-stabilized gold nanoparticles was determined to be (C18H37NH2)265·Au2822, and the experimental result showed that both the monodispersity and stability of these gold nanoparticles were beneficial to forming large areas of ordered two-dimensional arrangement at the air/water interface. [Copyright &y& Elsevier]

Abstract: The hydrophobic gold nanostructures with different shapes were prepared by using n-butanol situ reduction in cetyltrimethylammonium bromide (CTAB)/n-butanol/n-heptane/HAuCl4(aq) W/O microemulsion through microwave dielectric heating. The CTAB-stabilized gold nanoparticles and nanowires with a networked structure obtained through this method were characterized and analyzed by ultraviolet visible spectroscopy (UV–vis), transmission electron microscopy (TEM) and X-ray diffraction (XRD), respectively. The morphologies of the hydrophobic gold nanocrystals were successfully controlled through the adjustment of molar ratios of CTAB/HAuCl4 in the reverse microemulsion. The formation mechanism of anisotropic gold nanostructures was discussed, which demonstrated that CTAB played an important role in forming and stabilizing the shape of gold nanowires. [Copyright &y& Elsevier]

Polymer solutions have very important applications in the enhanced oil recovery due to their unique viscoelastic properties increasing microscale displacement efficiency. In this paper, the viscoelastic properties of partially hydrolyzed polyacrylamide (HPAM) solution have been investigated. Results show that the viscoelastic properties of HPAM increase with HPAM concentration increasing, and decrease with the increase of sodium dodccyl sulfate (SDS). Meanwhile, adding NaCl can destroy the viscoelastic properties. [ABSTRACT FROM AUTHOR]

Reasonable design of Pd-based catalysts with specific composition and morphology is of great importance for promoting the commercial application. of direct alcohol fuel cells (DAFCs). Recently, two-dimension (2D) with high density of defects and massive low-coordinated surface atom has become research highlights in the field of catalysis. Herein, we report a wet chemical method for synthesizing PdCu nanosheets with abundant wrinkles. The ultrathin two-dimensional structure endows catalysts plentiful catalytic active sites and large specific surface area, improving atomic utilization efficiency. The formation of bimetallic PdCu alloy structure leads to the adjustment of Pd electronic structure, resulting in lattice compression effect. Benefitting from the structural and compositional characteristics, PdCu nanosheets (NSs) exhibits excellent electrocatalytic performance for ethylene glycol oxidation reaction (EGOR) and glycerol oxidation reaction (GOR) with the mass activity of 7031 mA mg−1/5117 mA mg−1, which is 4.4/3.9 times higher than that of commercial Pd/C catalysts. Furthermore, the remained mass activity of PdCu NSs is 3991/3851 mA mg−1 after the durability measurement for EGOR/GOR, which confirm PdCu NSs possesses superior stability. We believe that our synthetic strategy could provide robust reference for the development of high-performance eletrocatalysts. [Display omitted] • PdCu nanosheets were prepared by a facile solvothermal method. • The PdCu NSs provide ideal electrocatalytic active sites. • The PdCu NSs exhibited excellent electrocatalytic performance toward EGOR and GOR. [ABSTRACT FROM AUTHOR]

[Display omitted] Metal organic frameworks (MOFs) are considered as promising electrocatalytic materials due to their tunable porosity, functional organic ligands, and large specific surface area for oxygen evolution reaction (OER). Recently, most reported electrocatalysts focus on the establishing heterogeneous structures by thermal treatments to improve OER performance. However, the thermal treatments are accompanied by the complex synthetic process and destruction of the MOFs structure. Therefore, improving the catalytic performance of pristine MOFs remains a challenge. Here, a series of trimetallic M a M b M c -MOFs (M represents metal element) were synthesized by one-pot method. Modulating the Co/Ni ratio not only adjusts the morphology of FeCoNi-MOFs, but also effectively optimizes the electronic structure. The composition-optimized FeCo 0.5 Ni 2.5 -MOF nano-bundles (FeCo 0.5 Ni 2.5 -NBs) only required a low overpotential of 273 mV to achieve the current density of 10 mA cm−2 in alkaline solution, with a Tafel slope of 51.1 mV dec−1, lower than other FeCoNi-MOFs and commercial RuO 2 catalyst. The two-electrode couple FeCo 0.5 Ni 2.5 -NBs || Pt/C achieved the cell voltage of 1.55 V, delivering current density of 10 mA cm−2 for overall water splitting. [ABSTRACT FROM AUTHOR]

The precise design and development of high-performing oxygen evolution reaction (OER) for the production of industrial hydrogen gas through water electrolysis has been a widely studied topic. A profound understanding of the nature of electrocatalytic processes reveals that Ni-based catalysts are highly active toward OER that can stably operate at a high current density for a long period of time. Given the current gap between research and applications in industrial water electrolysis, we have completed a systematic review by constructively discussing the recent progress of Ni-based catalysts for electrocatalytic OER at a large current density, with special focus on the morphology and composition regulation of Ni-based electrocatalysts for achieving extraordinary OER performance. This review will facilitate future research toward rationally designing next-generation OER electrocatalysts that can meet industrial demands, thereby promoting new sustainable solutions for energy shortage and environment issues. [ABSTRACT FROM AUTHOR]

Fe@CoMo 2 S 4 /Ni 3 S 2 /NF catalysts with enhanced conductivity, enlarged electochemical active areas and modulated electronic structure for efficient water splitting. [Display omitted] Oxygen evolution reaction (OER) is a multi-electron transfer process, whose intrinsic sluggish dynamic restricts the whole process of overall water splitting (OWS). To address this issue, a porous transition metal sulfide (TMS) catalyst with rich heterojunctions was prepared by vulcanization and trace Fe doping of CoMo-based metal–organic framework (MOF). In this work, the nanoflower composed of ultrathin 2D nanosheets anchored on a nickel foam presents a layered interface that contributes to the exposure of active regions. The resulting electrode denoted as Fe@CoMo 2 S 4 /Ni 3 S 2 /NF required a low overpotential (η 10 = 167 mV @ 10 mA cm−2, η 50 = 260 mV @ 50 mA cm−2) in 1.0 M KOH for OER and a small cell voltage (E = 1.513 V @ 10 mA cm−2) to power OWS when coupled with commercial Pt/C. It also exhibited splendid morphological and chemical stability with virtually invariant polarization curve and flower-like appearance after 1000 CV cycles, as well as long-term durability over 100 h with a constant current density of 10 mA cm−2. This work revealed the multi-anionic regulation mechanism in the surface reconstruction of sulfide electrocatalysts, and verified that Co/Mo/Ni-based oxysulfide was the true active substance of OER, which inspired the understanding and design of multi-anionic regulated electrocatalysts. [ABSTRACT FROM AUTHOR]

A series of PdAu nanospheres with wrinkled-surface are synthesized as efficient electrocatalysts for ethylene glycol and ethanol oxidation reactions. [Display omitted] • The universal and simple method of 3D Pd-based nanospheres with novel morphology are studied. • The introduction of Au effectively modifies the electronic structure of Pd. • The content of Au plays a key role in enhancing the electrocatalytic performances of PdAu NSs. • The superior electrocatalytic performances of PdAu NSs to EGOR and EOR were effectively confirmed compared to commercial Pd/C. Three dimensional (3D) noble-metal nanomaterials with special surface structures have been regarded as high-performance catalysts for alcohol oxidation on account of their superior thermal stability, electrical conductivity and large specific surface area. Although extensive efforts have been devoted to the preparation of 3D Pd-based catalysts with superior activity and stability, designing a simple, effective and eco-friendly method remains a challenge. Herein, we developed a facile one-step coreduction strategy to synthesize a series of 3D surface-wrinkled PdAu nanospheres (NSs) with tunable Pd/Au atomic ratios and found a universal method to prepare surface-wrinkled PdM (M = Au, Pt, Cu and Pb) NSs. Benefiting from the function of the surfactant cetyltrimethylammonium chloride (CTAC), the synthesized PdAu NSs with different composition possess abundant surface wrinkles, which is beneficial for exposing more electroactive centers. Attributed to the unique geometric morphology and optimized atomic ratio, the PdAu-2 NSs exhibited an optimal mass activity (MA) of 8103 mA mg−1 and 5113 mA mg−1 for the ethylene glycol oxidation reaction (EGOR) and ethanol oxidation reaction (EOR), which was 6.1 and 4.1 times that of commercial Pd/C, respectively. Moreover, the PdAu-2 NSs exhibited superb stability after long-term current–time (i-t) and cyclic voltammetry (CV) tests of the EGOR and EOR. This work not only provides new avenues to engineer PdAu NSs with enhanced electrocatalytic performance but also offers guidance for extending to more 3D PdM (M = other metals) NSs with novel morphology applied to fuel cell fields. [ABSTRACT FROM AUTHOR]

[Display omitted] • A one-pot strategy was developed for the successful formation of PdPtNi porous nanosheets. • The PdPtNi PNS provide ideal electrocatalytic active sites. • The PdPtNi PNS displayed improved electrocatalytic performance toward MOR and EOR. Bimetallic two-dimensional (2D) nanomaterials are widely used in electrocatalysis owing to their unique physicochemical properties, while trimetallic 2D materials of porous structures with large surface area are rarely reported. In this paper, a one-pot hydrothermal synthesis of ternary ultra-thin PdPtNi nanosheets is developed. By adjusting the volume ratio of the mixed solvents, PdPtNi with porous nanosheets (PNSs) and ultrathin nanosheets (UNSs) was prepared. The growth mechanism of PNSs was investigated through a series of control experiments. Notably, thanks to the high atom utilization efficiency and fast electron transfer, the PdPtNi PNSs have remarkable activity of methanol oxidation reaction (MOR) and ethanol oxidation reaction (EOR). The mass activities of the well-tuned PdPtNi PNSs for MOR and EOR were 6.21 A mg−1 and 5.12 A mg−1, respectively, much higher than those of commercial Pt/C and Pd/C. In addition, after durability test, the PdPtNi PNSs exhibited desirable stability with the highest retained current density. Therefore, this work provides a significant guidance for designing and synthesizing a new 2D material with excellent catalytic performance toward direct fuel cells applications. [ABSTRACT FROM AUTHOR]

A series of Pd-based nanosheets were synthesized by precisely controlling the feed ratio of Pd and Ru. Notably, Ru-PdRu heterostructure nanosheets, comprised of Ru and PdRu heterogeneous interface are endowed with sufficient catalytic active sites and modulated electronic structure, showing excellent performance towards alcohol oxidation reaction. [Display omitted] Fabricating 2D nanomaterials with heterogeneous structure is a feasible way to improve catalytic performance owing to its large surface area and tunable electron structure. However, such a category has not been widely reported in the field of alcohol oxidation reaction (AOR). In this work, we reported a new type of heterostructure nanosheet with Ru nanoparticles decorated around the edge of PdRu nanosheets (Ru-PdRu HNSs). Particularly, strong electronic interaction and sufficient active sites attributed to the construction of heterogeneous interface, is the key to the superior electrocatalytic behavior of Ru-PdRu HNSs towards methanol oxidation reaction (MOR), ethylene glycol oxidation reaction (EGOR), and glycerol oxidation reaction (GOR). Remarkably, owing to the enhanced electron transfer brought by the introduction of the Ru-PdRu heterogeneous interface, these novel nanosheets are highly durable. Apart from being able to maintain the highest current density after 4000 s chronoamperometry test, Ru-PdRu HNSs can be reactivated with negligible activity loss in MOR and GOR test after four consecutive i-t experiments. Impressively, in the EGOR test, after reactivation, the current density is step-wisely increased, making it one of the best AOR electrocatalysts. [ABSTRACT FROM AUTHOR]

A sequential template-engaged method was applied to design and construct unique Pt-NiCoFeP@NiCoFe-PBA hollow nanocages. Impressively, constructing heterointerfaces and incorporating ultralow Pt could induce strong synergistic effects and modify electronic configurations to optimize the binding energy of intermediates, thus achieving prominent electrocatalytic performance. [Display omitted] • Exploiting a partial phosphidation strategy to ingeniously construct heterostructures. • Ultralow Pt-loading to regulate electronic structure and increase active sites of catalysts. • Three-dimensional cage-like nanostructure could promote efficient charge transfer. • Pt-NiCoFeP@NiCoFe-PBA exhibits admirable electrocatalytic activity toward OER. Developing highly efficient electrocatalysts based on appropriate heterojunction engineering and electronic structure modification for the oxygen evolution reaction (OER) has been extensively recognized as an effective approach to increase the efficiency of water splitting. Herein, ultralow Pt-loaded (1 %) NiCoFeP@NiCoFe-PBA hollow nanocages with well-defined heterointerfaces and modified electronic environment are successfully fabricated. As expected, the obtained Pt-NiCoFeP@NiCoFe-PBA exhibits outstanding performance with a low overpotential of 255 mV at 10 mA cm−2 and a small Tafel slope of 57.2 mV dec-1. More specifically, the highly open three-dimensional structure, exquisite interior voids and abundant surface defects endow Pt-NiCoFeP@NiCoFe-PBA nanocages with more electrochemical active sites. Meanwhile, experimental results and mechanism studies also reveal that the construction of heterogeneous interfaces as well as incorporation of noble metals could readily induce strong synergistic effects and significantly tailor electronic configurations to optimize the binding energy of the intermediates, thereby achieving prominent OER performance. [ABSTRACT FROM AUTHOR]

As one of the most important energy generators, stretchable fuel cell has not been designed due to the reduced connection the electrocatalysts along with elongating. Herein, nitrogen doped double-walled carbon nanotubes coated on a poly(m-phenylene isophthalamide) fiber (NDWNTs/PMIA) has been designed as stretchable electrodes for oxygen reduction reaction (ORR). The strain-ORR activity test shows the ORR peak currents and the number of the transferred electrons of per oxygen molecule over NDWNTs/PMIA electrode keep super stable up to a high strain level of 100% (twice length of the original one). The NDWNTs/PMIA electrode at 100% strain has a comparable peak current to the commercial Pt-C coated PMIA fiber of 0% strain (Pt-C/PMIA), while the ORR capacity over Pt-C/PMIA electrode disappears at only 5% strain. The well maintained ORR capability of the NDWNTs/PMIA electrode is originated from tube-tube contact of NDWNT network from cross- to parallel-pattern induced by stretching, and thus ensures a stable ORR activity. The experimental results provide a new strategy to explore the highly stretchable electrodes that are significant to the development of stretchable fuel cells. [ABSTRACT FROM AUTHOR]

We herein successfully prepared the surface-bulged trimetallic PdAgCu nanospheres which showed superb photoelectronic response performance to EGOR. [Display omitted] • The surface-bulged trimetallic PdAgCu NSs were prepared via a facial co-reduction strategy. • The incorporation of Cu into PdAg NSs can modify the optical absorption property. • The photoelectrocatalytic performances of PdAgCu NSs were further enhanced with the assistance of visible light. • The introduction of Cu can strengthen the whole SPR effect of PdAgCu NSs. The notable surface plasmon resonance (SPR) effect of some metals has been applied to improve the efficiency of alcohol oxidation reactions, whereas the comprehensive investigation of Cu-assisted photoelectrocatalysis remains challenging. We herein successfully prepared trimetallic PdAgCu nanospheres (NSs) with abundant surface bulges for the advanced ethylene glycol oxidation reaction (EGOR) and compared them with bimetallic PdAg NSs to investigate the performance enhancement mechanism. Impressively, the as-optimized PdAgCu NSs exhibited superb mass activity and electrochemical stability. Moreover, under visible light illumination, the mass activity of PdAgCu NSs increased to 1.62 times compared to that in the dark, and in contrast, the mass activity of PdAg NSs only increased to 1.48 times that in the dark. A mechanistic study indicated that the incorporation of Cu not only strengthens the whole SPR effect of PdAgCu NSs but also further modifies the electronic structure of Pd. This work highlighted that the incorporation of Cu into PdAg NSs further enhanced the photoelectrocatalytic performance and increased noble metal atom utilization, which may provide guidance to fabricate novel and promising nanocatalysts in the field of photoelectrocatalysis. [ABSTRACT FROM AUTHOR]

[Display omitted] Porous nanospheres (PNSs) have great development prospects in the electrocatalysis field because of their structural characteristics, such as a large specific surface area. However, it is still a challenge to find a simple and energy-saving method for the controllable synthesis of PNS nanocatalysts. In this paper, a one-pot CTAC-assisted strategy was developed for the successful formation of PdPtAg PNSs with high porosity at room temperature. Benefitting from the unique structures, optimized composition, acceleration of charge transfer and enhanced resistance to CO poisoning, the PdPtAg PNSs displayed considerably improved electrocatalytic performance with high mass activity and stability toward the ethylene glycol oxidation reaction (EGOR) and glycerol oxidation reaction (GOR). The EGOR and GOR mass activities of PdPtAg were 5.00 A mg metal -1 and 3.06 A mg metal -1, which are 6.22 and 1.91 times that of commercial Pd/C, respectively. This work is expected to offer a new path for improving catalytic performance by simple design and adjustment of morphology. [ABSTRACT FROM AUTHOR]

Ultrasound was used for the self-assembly of precursors and high-performance kelp-like carbon nitride nanosheets were subsequently synthesized. [Display omitted] • Precursors were prepared by a fast and green ultrasonic self-assembly strategy. • Kelp-like carbon nitride nanosheets (CNS) were synthesized. • The controllable synthesis process of kelp-like CNS was elucidated. • The CNS has a unique morphology with high specific surface area and O-doping. The application of graphite carbon nitride photocatalysts is hampered by their low specific surface areas, few active sites, and low photogenerated electron-hole transfer rates. Here, we report a green and controllable strategy for synthesizing kelp-like carbon nitride nanosheets through self-assembled materials prepared from melamine and trithiocyanuric acid using sonochemistry. The prepared carbon nitride nanosheets showed superior and long-lasting photocatalytic activity in hydrogen evolution and the degradation of tetracycline hydrochloride. The significantly enhanced photocatalytic performance of carbon nitride nanosheets is attributed to the curled porous nanosheet structure and the appropriate amount of O-doping. This work provides a new design strategy for preparing shape-controlled carbon nitride catalysts via a green, fast, sonochemically mediated self-assembly approach. [ABSTRACT FROM AUTHOR]

The RuM (M=Ni, Co) porous nanorods are prepared as efficient electrocatalysts for the HER. [Display omitted] • The RuM (M = Ni, Co) HNRs were synthesized via wet-chemical method and cation-etching approach. • The hollow nanorod structures effectively enriched the active sites with easy accessibility. • Ni/Co-doping optimized the electronic structure of Ru. • The RuM (M = Ni, Co) HNRs exhibited excellent HER catalytic performance and high stability. The development of efficient and stable nanomaterial electrocatalysts for the hydrogen evolution reaction (HER) is of great significance for renewable energy conversion via water electrolysis. Herein, we have developed a novel class of bimetallic RuM (M = Ni, Co) hollow nanorods (HNRs) through a facile Fe3+ etching strategy, as electrocatalysts for enhancing the HER. Morphological physical characterization and electrochemical tests demonstrated that RuM (M = Ni, Co) HNRs with hollow structures can effectively enhance electrocatalytic activity due to their high specific surface areas. Impressively, the RuNi HNRs exhibited superior HER performance with an overpotential of merely 25.6 mV in 1 M KOH solution at 10 mA cm−2, which is significantly lower than that of commercial Pt/C (44.7 mV). Moreover, the as prepared RuNi HNRs showed excellent stability and could continuously work at a current density of 10 mA cm−2 for 40 h with a negligible increase in potential. The Ru-based HNRs also showed high HER activity in an acidic solution. This study paves a new way for the universal fabrication of bimetallic hollow structured nanomaterials as efficient electrocatalysts for boosting the HER. [ABSTRACT FROM AUTHOR]

The noble metal anodic catalysts with three-dimension (3D) chain-like network structure have been researched thoroughly due to their unique morphological characteristics. Herein, a novel scheme has been designed rationally to synthesize 3D PdPb nanochain networks (PdPb NCNs). Numerous nanochains were interlaced and stacked to form the nanonetworks, which were contributed to improving electrocatalytic performance. Abundant steps and kinks existed on the nanochain networks, which provided plentiful active sites to improve the electrocatalytic activity. In the subsequent electrochemical tests, the mass activity of Pd 65 Pb 35 NCNs was 4.47 A mg pd −1, higher than other catalysts. Moreover, in the chronoamperometry and consecutive CV measurements, Pd 65 Pb 35 NCNs exhibited the best stability than other prepared samples. This work explored the rational synthesis of PdPb nanochain networks, and confirmed the excellent electrocatalytic performance in EGOR. [Display omitted] • The intertwined nanochain network structure was beneficial to optimize the electron transport process. • The catalyst components were optimized by controlling the amount of Pb(HCOO) 2. • Pd 65 Pb 35 NCNs displayed the excellent electrocatalytic activity and stability in EGOR. [ABSTRACT FROM AUTHOR]

[Display omitted] • An ultrasensitive photoelectrochemical (PEC) was fabricated based on pillar[5]arenes functionalized Au and BiOBr nanoflowers (Au@WP5/BiOBr). • The immunosensor is specifically in bovine hemoglobin (BHb) sensing. • The COOH groups in BHb molecules formed a hydrogen bond with the NH 2 groups of DA, achieving an indirect detection of BHb. • The LSPR effect of Au NPs, the host–guest interaction between WP5 and DA, the photo generated electron-holes of BiOBr nanoflowers are responsible for the enhanced PEC performance. • The proposed sensor displays ultralow detection limit. In this work, the ultrasensitive photoelectrochemical (PEC) sensor for the detection of bovine hemoglobin (BHb) was developed based on water-soluble pillar[5]arenes (WP5) functionalized gold nanoparticles (Au NPs) and bismuth oxybromide (BiOBr) nanoflowers (Au@WP5/BiOBr). The photoelectrical signal of dopamine (DA) was decreased after adding the different concentrations of BHb due to the formation of hydrogen bond between the COOH groups of BHb molecules and the NH 2 group of DA, which could achieve the indirect detection of BHb. Benefiting from the photo-generated electron-holes of BiOBr nanoflowers, the localized surface plasmon resonance (LSPR) effect of Au NPs, the host–guest interaction of WP5 between and DA, the PEC sensor showed a specifically recognize toward BHb with a wide detection range of 1.0 × 10−11–1.0 × 10−1 mg/mL and a detection limit of 4.2 × 10−12 mg/mL (S/N = 3). Additionally, the proposed PEC sensor also displayed good stability, remarkable selectivity and provided a promising strategy of design pillar[5]arenes functionalized photoelectric activity nanomaterials for PEC sensing application. [ABSTRACT FROM AUTHOR]

A novel CoTe-C composite has been designed and prepared as a support of Pd catalyst for the electrooxidation of ethylene glycol. [Display omitted] • The CoTe-C composite has been fabricated as a support of Pd catalyst for the ethylene glycol oxidation reaction (EGOR) for the first time. • The effect of CoTe-C carrier on electrocatalytic performance for EGOR has been studied. • The Pd/CoTe-C catalyst exhibits high catalytic performance and stability for EGOR in alkaline medium. The development of highly active and earth-rich electrocatalysts remains a formidable challenge for the commercialization of fuel cells. Herein, a composite carrier composed of cobaltous telluride (CoTe) and carbon (C) has been designed for the first time to enhance the electrocatalytic performance of palladium (Pd) nanoparticles (NPs) for the electro-oxidation of ethylene glycol (EG). Remarkably, the mass activity for the as-prepared Pd/CoTe-C catalyst during the ethylene glycol oxidation reaction (EGOR) is found to reach up to 3917.3 mA mg−1, which is 2.2 times higher than that of Pd/Co-C (1785.0 mA mg−1) and 4.1 times greater than that of commercial Pd/C catalyst (962.4 mA mg−1), exceeding that obtained for most Pd-based electrocatalysts reported thus far. In particular, the Pd/CoTe-C catalyst shows better electrochemical stability toward the EGOR than the Pd/Co-C and commercial Pd/C catalysts. Thus, the Pd/CoTe-C electrocatalyst is expected to exhibit broad application prospects in the field of fuel cells. [ABSTRACT FROM AUTHOR]

We render maneuverable synthesis of a series of 2D Pd nanoplates with progressively enriched nanopores. This study proposes a nanopore tunable synthetic strategy based on multilayer 2D platform, which originates from the integrated manipulation of the reaction kinetics and the in situ generated joint etchants. [Display omitted] • The synthesis of Pd NPs depends on synergetic adsorption of CO and acetylacetone. • Nanopore engineering of mesh Pd NPs derived from in situ generated etchants. • DFT calculations clarify Pd sites near nanopore alleviate Pd-O overbinding issue. Two-dimensional (2D) nanomaterials with nanopore display an enhancement effect on electrocatalysis behavior, whereas the nanopore engineering for 2D nanocatalysts remains an insurmountable challenge. We advance the synthesis of multilayer Pd nanoplates (Pd NPs) and two types of meshy nanoplates (Pd LMNPs/MNPs) with escalating nanopores from none and sparse to porous. Specially, an in situ nanopore enrichment on these Pd nanoplates hinges on a joint etching strategy with integrated manipulation of reaction kinetics. The optimized Pd MNPs exhibit exceptional oxygen reduction reaction performance, owing to the enhanced intermediates protonation on Pd site neighboring nanopore, which has been elucidated by density functional theory calculations. In addition, Pd MNPs also deliver excellent performances in fuel cell anodic reactions, including ethanol oxidation reaction and formic acid oxidation reaction. This study highlights a new strategy for in situ nanopores engineering , providing a prospect for designing superior nanocatalysts. [ABSTRACT FROM AUTHOR]

A facile one-step method is adopted to design multi-low-dimensional PdPt nanomaterials by using different Pd precursors. 0D-2D PdPt NCs delivered better activity and stability than 2D PdPt NAs towards EOR/EGOR. The promotion mechanism is investigated on PdPt nanocrystals with different low-dimension. [Display omitted] • A facile one-step method is adopted to design low-dimension nanomaterials. • A novel kind of 0D-2D and 2D PdPt nanocrystals are precise reconstruction by altering the types of precursors. • 0D-2D PdPt NCs delivered better activity and stability than 2D PdPt NAs towards EOR/EGOR. • The promotion mechanism is investigated on PdPt nanocrystals with different low-dimension. Low-dimensional noble-metal materials (LDNMs) with different structural advantages have been considered as the high-performance catalysts for C 2 alcohol electrooxidation. However, it is still a great challenging to precisely construct nanomaterials with low-dimensional composite structure thus to take advantages of various dimension, especial without the surfactant participation. Most studies focus on the modulation of the single dimensional nanocatalysts, the correlation between electrocatalytic performances and low-dimension composite have been rarely reported. Herein, we engineered a simple one-step approach to design multi-low-dimensional PdPt nanomaterials by using different Pd precursors. The low-dimensional PdPt nanocrystals (NCs) composed of zero dimension (0D) dendrite-like nanoparticles and two dimension (2D) nanosheets were obtained by using Pd(OAc) 2 , and meanwhile the 2D PdPt nanosheet assemblies (NAs) were synthesized by the introduction of NaPdCl 4. Specifically, benefitting from the unique low-dimension structures with fast electron/mass transfer, and optimized electronic and synergistic effect, the multi-low-dimensional 0D-2D PdPt NCs showed the highest ethanol oxidation reaction (EOR)/ethylene glycol oxidation reaction (EGOR) mass activities, which were much higher than 2D PdPt NAs. The 0D-2D PdPt NCs also exhibited the highest structural stability. Generally, this work could inspire more advanced designs for surfactant-free synthesis and promote the fundamental engineering on nanocatalysts with low-dimension composite structure for electrocatalytic fields. [ABSTRACT FROM AUTHOR]

Nanofirework-like PtRu alloy catalyst has been successfully synthesized and used as an efficient anodic catalyst for glycerol oxidation reaction (GOR) in alkaline medium. [Display omitted] • A class of firework-like bimetallic PtRu alloy nanocatalysts has been successfully fabricated. • The addition of Ru can effectively tune the electronic structure of Pt and greatly improve the performance of the catalyst. • The electrocatalytic properties of bimetallic PtRu catalysts strongly rely on their chemical composition. Electro-oxidation of glycerol is a key anodic reaction in direct alcohol fuel cell (DAFCs). Exploring the cost-effective nanocatalysts for glycerol oxidation reaction (GOR) is very important for the development of DAFC, but it is still challenging. In this paper, nanofirework-like PtRu alloy catalyst was successfully synthesized and used for GOR in alkaline medium. Thanks to the unique nanofirework-like structure and synergetic effects, the activity and stability of the as-prepared PtRu alloy nanofireworks (NFs) toward GOR were significantly improved relative to Pt NFs. In particular, the peak current density of GOR catalyzed by the optimized Pt 1 Ru 3 NFs catalyst reached 2412.0 mA mg−1, surpassing that of commercial Pt/C catalyst. This work has important guidance for the design of advanced anode electrocatalysts for fuel cells. [ABSTRACT FROM AUTHOR]

3D PdAg superstructures composed of hollow interior and 2D nanosheets shell, serving as highly active and selective EOR catalyst. [Display omitted] • We proposed for the first time that the Pd-Ag system facilitate the complete oxidation of ethanol. • A facile one-pot synthesis has been proposed for the synthesis of a holllow 3D open structure. • The 3D hollow PdAg superstructures achieve highly selective ethanol electrooxidation. Direct ethanol fuel cells (DEFCs) have been considered as future power devices for many portable applications. The ethanol oxidation reaction (EOR), that is, a multielectron process, suffers from low efficiency owing to the high selectivity to the 4e− pathway (C2 pathway) and low selectivity to the 12e− pathway (C1 pathway). The preparation of efficient catalysts with high C1 pathway selectivity is regarded as a promising and fascinating field. Herein, we first advance a one-pot synthesis of 3D PdAg superstructures (SSs) with a hollow interior and ultrathin nanosheet shell. PdAg SSs achieve a mass activity of 5.27 A mg−1 for the alkaline EOR and a Faraday efficiency of 22.7 % for the C1 pathway, which is 5.7 and 7.5 times higher than that of commercial Pd/C, respectively. Mechanism studies confirm that the construction of the Pd-Ag system greatly facilitates the oxidation of the C1 intermediates (*CH 3 and *CO) and enhances the C C bond cleavage ability of the catalyst. This work not only highlights an active Pd-based catalyst for the selective EOR, but also sheds light on the formation of 3D open nanostructure via self-assembly of 2D nanosheets. [ABSTRACT FROM AUTHOR]

Efficient synthesis of a sequence of low-dimensional PdAg networked nanochains assembled from nanoparticles with accelerated reaction kineties, boosted anti-CO poisoning and enhanced electrocatalytic performance toward EGOR and EOR. [Display omitted] • The novel synthesis of low-dimensional PdAg networked nanochains with 0D-1D composite structure are studied. • Ag assisted PdAg networked nanochains with abundant surface defects evidenced the modified electron structure of Pd. • The content of Ag plays a key role in enhancing the electrocatalytic performances of PdAg-2 NNCs. • The superior electrocatalytic performances of low-dimensional PdAg networked nanochains to EGOR and EOR were effectively confirmed compared to commercial Pd/C. Advanced 1D materials have become the focus due to the enhanced structure durability than 0D nanoparticles (NPs). Unfortunately, the unique electrocatalysts with 0D-1D composite structure are rarely reported. Herein, the low-dimensional PdAg networked nanochains (NNCs) with diverse element composition assembled from a sequence of NPs were designed as efficient 0D-1D electrocatalysts toward the ethylene glycol oxidation reaction (EGOR) and ethanol oxidation reaction (EOR). The low-dimensional PdAg NNCs not only possess stronger structure stability than 0D NPs, but also endow catalysts with more abundant active sites than traditional 1D nanochains. Attributed to the synergistic electronic effect, abundant active sites and surface defects, the composition-optimized PdAg-2 NNCs behaved the optimal electrocatalytic activities, greatly surpassing most of reported studies. Benefiting from 0D-1D composite structure and stable networked nanochain feature, the PdAg-2 NNCs still remained higher current density after the 3600 s chronoamperometry (CA) experiment and without obvious decline through three consecutive CA tests compared to commercial Pd/C, revealing the remarkable stability. Meanwhile, the PdAg-2 NNCs exhibited the prominent anti-CO poisoning ability and the lowest onset oxidation potential, manifesting the enhanced reaction kinetics. This work fabricated a novel electrocatalyst with low-dimension composite structure, producing new guidelines for the synthesis of high-efficiency electrocatalysts. [ABSTRACT FROM AUTHOR]

Ru-modified NiFe MOF nanosheet array was elaborately designed via self-driven galvanic replacement reaction (GRR), which exhibits dramatically enhanced HER, OER and UOR catalytic property as a multifunctional electrocatalyst. [Display omitted] • Ru-modified NiFe MOF nanosheet array was designed via self-driven galvanic replacement reaction. • Enhanced catalytic potency benefitted from spontaneous electronic reconstruction in the interface. • The Ru-NiFe- x /NF are endowed with richer high-valence Ni active species. • The Ru-NiFe- x /NF can operate as multifunctional electrocatalyst with high current density. Urea electro-oxidation reaction (UOR) has been a promising strategy to replace oxygen evolution reaction (OER) by urea-mediated water splitting for hydrogen production. Naturally, rational design of high-efficiency and multifunctional electrocatalyst towards UOR and hydrogen evolution reaction (HER) is of vital significance, but still a grand challenge. Herein, an innovative 3D Ru-modified NiFe metal-organic framework (MOF) nanoflake array on Ni foam (Ru-NiFe- x /NF) was elaborately designed via spontaneous galvanic replacement reaction (GRR). Notably, the adsorption capability of intermediate species (H*) of catalyst is significantly optimized by Ru modification. Meanwhile, rich high-valence Ni active species can be acquired by self-driven electronic reconstruction in the interface, then dramatically accelerating the electrolysis of water and urea. Remarkably, the optimized Ru-NiFe-③/NF (1.6 at% of Ru) only requires the overpotential of 90 and 310 mV to attain 100 mA cm−2 toward HER and OER in alkaline electrolyte, respectively. Impressively, an ultralow voltage of 1.47 V is required for Ru-NiFe-③/NF to deliver a current density of 100 mA cm−2 in urea-assisted electrolysis cell with superior stability, which is 190 mV lower than that of Pt/C-NF||RuO 2 /NF couple. This work is desired to explore a facile way to exploit environmentally-friendly energy by coupling hydrogen evolution with urea-rich sewage disposal. [ABSTRACT FROM AUTHOR]

Herein, we developed a one-pot, surfactant-free approach to obtain a PdPtAu@Pd core@shell catalyst for the photocatalytic methanol oxidation reaction. By virtue of its dimensions, conjunction architecture and robust core@shell construction, 0D@2D PdPtAu@Pd exhibited a superior catalytic performance, with a mass activity 2.3- and 6.7-times higher than that of Pt/C and Pd/C catalysts, respectively. [ABSTRACT FROM AUTHOR]

A series of CoNi-based CoNiM (M= Fe, Cd, Ce, Cu, Mn, Zn) LTHs nanocatalysts with ultrathin nanosheet configuration are prepared as efficient electrocatalysts for OER. [Display omitted] • We developed a simple MOF-mediated method for synthetizing ultrathin 2D CoNiFe LTHs. • The modified electronic structure leads to high OER activity of the CoNiFe LTHs. • This work will boost the synthesis of ternary layer hydroxide catalysts. Developing low-budget, stable, and high-performance electrocatalyst toward oxygen evolution reaction (OER) is of pivotal significance in the fields of energy conversion and storage. Herein, a universal metal organic framework (MOF)-mediated method for the synthesis of two-dimensional (2D) layered triple hydroxides (LTHs) nanosheets with ultrathin nature has been developed. It is interesting to disclose that the CoNi-based LTHs possess better electrochemical catalytic performance, giving superior performance to commercial RuO 2 catalysts. Remarkably, benefitting from the ultrathin nanosheet configuration, optimized electronic structure, and strong synergistic effect, the optimized CoNiFe LTHs nanosheets show excellent OER performance with an ultralow overpotential of 262 mV at a current density of 10 mA cm−2 and a small Tafel slope of 88.1 mV dec-1. This work provides a promising avenue to develop low-cost and high-performance layered ternary hydroxide electrocatalysts. [ABSTRACT FROM AUTHOR]

[Display omitted] Recently, intensive attention has been attracted to the two-dimensional metal nanosheets, owing to their excellent electrocatalytic performance for direct alcohol fuel cells (DAFCs). Herein, PdRu nanosheets have been synthesized successfully by a facile one-pot method. The rugged nanosheet structure provided plentiful surface active sites to enhance the electrocatalytic activity. Moreover, benefiting from the synergistic effect and improved electronic structure, PdRu NSs exhibited splendid electrocatalytic performance in ethylene glycol oxidation reaction (EGOR) and glycerol oxidation reaction (GOR). Specifically, the mass activity of PdRu NSs was 1.72 and 3.69 times over those of Pd NSs and Pd/C catalysts in EGOR. Moreover, PdRu NSs displayed the largest mass activity in GOR, 1.48 and 2.47 times as large as Pd NSs and Pd/C catalysts. The results of stability tests demonstrated that the durability of PdRu NSs was the highest among the obtained catalysts. This work plays a directive role on the in-depth engineering on Pd-based catalysts with nanosheet architectures. [ABSTRACT FROM AUTHOR]

Abstract: An efficient photocatalytic hydrogen evolution system based on triphenylamine-based dye functionalized bimetallic Au@Pt core/shell nanocomposite (Au@Pt-TPAD) was reported. Transmission electron microscopy (TEM), X-ray diffraction (XRD) and UV–vis absorption spectra suggested that Au@Pt-TPAD nanocomposite consisted of a bimetallic nanoparticle with Au core and Pt shell nanostructure. The photoelectrochemical result suggested that photoinduced electrons could efficiently transfer from the triphenylamine derivative molecules to the bimetallic nanoparticles. Photocatalytic results showed that the Au@Pt2-TPAD bimetallic nanocomposite could be used as a stable photoinduced H2 evolution photocatalyst. Compared with the monometallic counterpart (Au-TPAD or Pt-TPAD), the bimetallic nanocomposite showed much higher catalytic activity for the photocatalytic hydrogen evolution. The amount of hydrogen evolution on the optimal catalyst under 12 h UV–vis light irradiation was about 37.5 μmol. The enhancement of the photocatalytic activity might be attributed to the synergistic effect between the two metals in bimetallic nanoparticles with core/shell structure. This investigation might open up new opportunities for the development of dye functionalized heterometallic nanocomposite with enhanced photocatalytic performance. [Copyright &y& Elsevier]

Abstract: We developed a novel nonenzymatic biosensor based on palladium/poly(3,4-ethylenedioxythiophene) (Pd/PEDOT) nanocomposite modified glassy carbon electrode (GCE) for the detection of hydrogen peroxide (H2O2). Pd/PEDOT has been successfully fabricated by a facile one-pot ‘green’ method using H2PdCl4 as an oxidant and a source of metal nanoparticles without any surfactants and templates. The as-synthesized PEDOT nanospheres are quite uniform in size (∼60nm) without aggregation and provide a good platform for anchoring the Pd nanoparticles (NPs). Pd NPs (∼4.5nm) are homogenously dispersed on surface of PEDOT nanospheres. The Pd/PEDOT nanospheres on GCE exhibit a good electrocatalytic activity towards the H2O2 reduction. The electrochemical response of Pd/PEDOT to H2O2 exhibits a low detection limit of 2.84μM in the range of 2.5×10−3–1.0mM with a high sensitivity, good repeatability, acceptable reproducibility and good long-term stability. The good recoveries achieved in spiked human urine samples demonstrated the potential application of Pd/PEDOT for H2O2 detection. [Copyright &y& Elsevier]

The supported palladium catalysts were prepared by depositing Pd colloidal particles on boehmite, and then promoted by lanthanum oxide. The samples were characterized by transmission electron microscopy, powder x-ray diffraction, scanning electron microscopy, and energy dispersive x-ray spectroscopy, and studied in hydrogenation of 2-tertiary butyl anthraquinone (BAQ) to 2-tertiary butyl anthrahydroquinone (BAQH4) for H2O2 production. Compared to the catalyst prepared by metal salt impregnation method, the supported Pd nanoparticles catalyst showed high catalytic activity. Superior catalytic activity of the catalyst was related to the high dispersion of the active components and the existence of lanthanum oxide as an effective promoter, which may promote the catalytic activity both electronically and morphologically. The reaction kinetics for the catalytic hydrogenation of BAQ to BAQH2 can be described by equation r = kC BAQ  · p H 2 , and the apparent activation energy is 38 kJ · mol−1. [ABSTRACT FROM PUBLISHER]

Abstract: A new type of graphene-based nanohybrid was prepared from graphene nanosheets and 4-(diphenylamino)benzaldehyde (TPA-CHO) through 1,3-dipolar cycloaddition. The nanohybrid was modified by platinum nanoparticles via photodeposition. The nanohybrid and its Pt modified nanocomposite were characterized by atomic force microscopy (AFM), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Ultraviolet–visible absorption (UV–vis), Fourier transform infrared (FTIR), and Raman spectra confirmed that triphenylamine moiety grafted on the graphene surface. The results of fluorescence quenching and photocurrent enhancement of the triphenylamine-functionalized graphene revealed that photoinduced electron transfer from triphenylamine moiety to the graphene sheet. The investigation of using the Pt modified graphene-based nanocomposite as a photocatalyst for H2 evolution showed that under UV–vis light irradiation, the average H2 evolution rate and the quantum efficiency is 2.3 μmol h−1 and 0.45% mol E−1, respectively. This work demonstrated a potential application of an organic sensitizer covalently functionalized graphene as a novel photocatalyst in the field of solar energy conversion. [Copyright &y& Elsevier]

Herein, 1,3,6,8-pyrenetetrasulfonic acid (PTSA) functionalized Pt nanocomposites were synthesized and characterized by UV/vis, X-ray photoelectron spectroscopic (XPS), FTIR, TEM, and XRD methods. Pyrenetetrasulfonic acid was not only used as the stabilizer to prevent agglomeration of Pt nanoparticles but also served as the light-harvesting photosensitizer, absorbing irradiating light and transferring photoexited electrons to the platinum nanoparticles. The occurrence of the photoinduced electron transfer process was confirmed by the combination of time-resolved fluorescence and photoelectrochemical spectral measurements. Photocatalytic results showed that PTSA functionalized Pt nanocomposites could be used as stable photocatalysts for photoinducing H2 evolution. At the optimal reaction conditions ( nPt: nPTSA=100, pH 3), enhanced amounts of hydrogen were evolved from the system under UV/vis irradiation in the absence of an electron mediator. The corresponding amount of hydrogen evolution was 125.1 μmol for 12 h exposure to UV/vis irradiation, and the apparent quantum efficiency at a wavelength of λ=365 nm was 11.5 %. [ABSTRACT FROM AUTHOR]

Abstract: Nitrogen doped graphene was synthesized from graphite oxide and urea by thermal solid-state reaction. The samples were characterized by transmission electron microscopy, atomic force microscopy, scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, Raman spectra, element analysis, and electrical conductivity measurement. The results reveal that there is a gradual thermal transformation of nitrogen bonding configurations from amide form nitrogen to pyrrolic, then to pyridinic, and finally to “graphitic” nitrogen in graphene sheets with increasing annealing temperature from 200 to 700°C. The products prepared at 600°C and 700°C show that the quantity of nitrogen incorporated into graphene lattice is ∼10at.% with simultaneous reduction of graphite oxide. Oxygen-containing functional groups in graphite oxide are responsible for the doping reaction to produce nitrogen doped graphene. [Copyright &y& Elsevier]

Abstract: A Pt-based composite electrode material has been developed by dispersing Pt nanoparticles on a porous poly(o-methoxyaniline) (POMA) film, which was produced via electropolymerization on a glassy carbon (GC) electrode. As-formed Pt/POMA/GC electrode was characterized by SEM, EDX and electrochemical analysis. Furthermore, the composite electrode material was evaluated by its electrocatalytic performance for formic acid oxidation using cyclic voltammetry and chronoamperometry methods. Compared to Pt deposited on bare GC (Pt/GC), Pt/POMA/GC exhibits higher catalytic activity and stronger poisoning-tolerance ability towards formic acid electro-oxidation. The improved performance is attributed to the synergetic effect between Pt and POMA. Also, as demonstrated by CO stripping voltammograms, the interference of CO on Pt/POMA/GC is greatly weakened. These results suggest that the POMA film has great potential to serve as a promising support material for the electrocatalytic oxidation of formic acid. [Copyright &y& Elsevier]

Abstract: A new system for photoinduced hydrogen production has been constructed using a porphyrin–pyrene conjugate functionalized Pt nanocomposite as a photocatalyst and ethylenediaminetetraacetic acid (EDTA) as a sacrificial reductant in the absence of an electron mediator. Detailed spectral, computational and photochemical studies reveal that a photoinduced energy transfer from the photoexcited state of pyrene to the porphyrin occurs, accompanied by an electron transfer from the excited porphyrin moiety to the platinum catalyst for the H2 generation. Efficient photocatalytic hydrogen evolution from the system demonstrates the possibility of constructing a photocatalytic system that uses a Pt nanocomposite functionalized by self-assembled donor–acceptor conjugates as a photocatalyst. The turnover numbers (TONPt and TONdye) and quantum yields of hydrogen () for the photoinduced hydrogen production system are 63, 6311, and 2.65%, respectively, and are calculated on the basis that the total amount of H2 evolved after 12 h of irradiation. [Copyright &y& Elsevier]

Abstract: Electrocatalytic activities of the monometallic Pt and bimetallic Pt–Ru nanoparticles dispersed onto polycarbazole (PCZ) films obtained by the electropolymerization on glassy carbon electrode (GC) (i.e., Pt/PCZ/GC, Pt–Ru/PCZ/GC) towards formic acid oxidation have been investigated using cyclic voltammetry and chronoamperometry methods. As-formed electrodes are characterized by SEM, EDX and electrochemical analysis. Relative to Pt and Pt–Ru deposited on the bare GC (i.e., Pt/GC and Pt–Ru/GC), Pt/PCZ/GC and Pt–Ru/PCZ/GC, respectively, exhibit higher catalytic activity and stronger poisoning-tolerance ability towards formic acid electrooxidation. The enhanced performance is proposed to come from the synergetic effect between metal nanoparticles (Pt, Pt–Ru) and PCZ. At the same time, the results of the stripping voltammograms of CO show that PCZ can weaken largely the adsorption strength of CO on catalysts and can make CO oxidation easier under lower potential, implying further that PCZ can be used as an efficient promoter for electrocatalytic oxidation of formic acid on Pt/PCZ and Pt–Ru/PCZ catalysts. [Copyright &y& Elsevier]

Abstract: Pt is one of the most important electrode materials employed in direct methanol fuel cell, and many efforts have been directed to improving its electrocatalytic performance. In this work, Pt–TiO2 nanocomposites are successfully prepared by a sol–gel method. As revealed by TEM, Pt nanoparticles with an average size of 2.6 nm are well uniformly dispersed on porous TiO2. XRD structural characterization indicates that Pt possesses a face centered cubic crystal structure while TiO2 is in the format of both rutile and anatase phases. The electrochemical performance of as-prepared nanocomposite electrode (Pt–TiO2/ITO) is evaluated by studying the electrocatalytic oxidation of methanol in an alkaline medium with or without UV illumination. Comparative experiments evince that the electrochemical performance of Pt–TiO2/ITO for methanol electrooxidation is markedly improved under UV illumination. Under UV illumination, moreover, the poisoning resistance of Pt–TiO2/ITO for methanol electrooxidation is significantly improved, as supported by the results of time-coursed current measurements. [ABSTRACT FROM AUTHOR]

Abstract: A facile, one-step and template-free electrodeposition method has been developed for the first time to prepare porous Pt nanoflowers. The flowerlike architectures were confirmed by SEM, and further structurally characterized by XRD and electrochemical analyses. Compared to conventional nanosized Pt catalysts, as-prepared Pt nanoflowers exhibit remarkably higher catalytic activity and stronger poisoning-tolerance for the methanol electro-oxidation, and thus they are anticipated to find interesting applications in many important fields such as energy and catalysis. [Copyright &y& Elsevier]

Abstract: A tetraphenylporphyrin bearing four naphthalene donor moieties (5,10,15,20-tetrakis(4-(naphthalen-1-ylmethoxy)phenyl)porphyrin were synthesized and characterized using 1H NMR, FTIR, UV–vis, FL, TEM, and XRD. Substituting the naphthalene groups onto the porphyrin ring led the molecule to absorb over a broader range (200–700 nm) and to undergo efficient intramolecular energy transfer from the naphthalene to the porphyrin ring. FTIR, XRD and TEM analyses indicated that within a functionalized platinum nanocomposite comprising the porphyrin, the photoreceptive dye forms a shell containing a nanosize Pt core (∼2.8 nm). The photocatalytic activity of the Pt nanocomposite towards water reduction to hydrogen was >twice that of a Pt-naphthalene-free porphyrin system. The turnover numbers (TONPt and TONdye) and quantum yields of hydrogen were 72, 7200 and 3.0%, respectively, calculated on the basis of the total amount of H2 evolved after 12 h irradiation. [Copyright &y& Elsevier]

Abstract: A novel composite catalyst, Pt nanoparticles supported on poly(5-nitroindole) (Pt/PNI), has been successfully prepared by the electrochemical method and used for the electrooxidation of methanol in alkaline media. As-prepared Pt/PNI was characterized by SEM, EDX and electrochemical methods. The results of the catalytic activity for methanol oxidation showed that Pt/PNI had higher catalytic activity and stronger poisoning-tolerance than Pt/Pt, Pt/GC and the common Pt electrode. The effects of different parameters related to the methanol oxidation reaction kinetics, such as Pt loading, mass of PNI film, concentration of methanol and KOH, potential scan rate, have also been investigated. The present study showed a promising choice of Pt/PNI as composite catalyst for methanol electrooxidation in alkaline medium. [Copyright &y& Elsevier]

Au/Pt bimetallic core/shell nanoparticles that were stabilized by polyaryl ether trisacetic acid ammonium chloride dendrons (G3NACl) were synthesized and used as catalysts for the hydrogenation of 3-phenoxybenzaldehyde to 3-phenoxyphenyl methanol and nitrobenzenes to anilines. Transmission electron microscopy (TEM), X-ray diffraction (XRD), and UV-visible absorption spectroscopy revealed that Au/Pt bimetallic nanoparticles with a 6-nm Au core and average overall diameters of 9.0 ± 2.4 nm, 10.4 ± 2.8 nm, and 13.0 ± 3.2 nm for Au75Pt25@G3NACl, Au50Pt50@G3NACl, and Au25Pt75@G3NACl, respectively, had formed. Au/Pt bimetallic nanoparticles showed higher catalytic activity for the hydrogenation of nitrotoluenes to anilines and 3-phenoxybenzaldehyde to 3-phenoxyphenyl methanol as compared to monometallic platinum nanoparticles and physical mixtures of monometallic Pt and Au nanoparticles. The higher activity of the Au/Pt bimetallic nanoparticles may be attributed to the fact that the gold core attracts electrons from platinum. The electron-deficient platinum shell may favor the adsorption of the substrate with polar carboxyl groups. [ABSTRACT FROM AUTHOR]

Bimagnetic Pt3Co/Fe3O4 nanocomposite is synthesized in aqueous solution. The nanoparticles are characterized with TEM, FTIR, and magnetic measurements. The as-synthesized nanocomposite exhibits ferromagnetic properties at room temperature due to the exchange coupling between Pt3Co and Fe3O4. Magnetic properties of Pt3Co/Fe3O4 nanoparticle can be tuned by varying of the molar ratio of iron to platinum. Pt3Co/Fe3O4 nanoparticles exhibit higher saturation magnetization when the molar ratio of iron to platinum is 1. [ABSTRACT FROM AUTHOR]

Abstract: Homogeneous and high-strength free-standing poly(1,12-bis(carbazolyl)dodecane) film with conductivity of 1.36 S cm−1 and a tensile strength of 230 kg cm−2 was electrochemically synthesized in a novel mixed electrolyte of boron trifluoride diethyl etherate containing 40% CHCl3 (by volume) by direct anodic oxidation of the monomer 1,12-bis(carbazolyl)dodecane). To the best of our knowledge, this is the first report that free-standing polycarbazole films with high strength and high conductivity can be electrodeposited on stainless steel sheet. [Copyright &y& Elsevier]