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Mulberry-like AuPtAg porous hollow nanorods (PHNR) were facilely synthesized for the first time via a wet chemical method, where Au nanorods (Au NR) behaved as sacrificed template. The anisotropic oriented growth and etching process are involved in this synthesis. Their structural and electronic characteristics were scrutinously examined by TEM, EDS, XPS, and electrochemical techniques. The AuPtAg PHNR provided a large specific surface area and exposed a large number of active sites, showing highly enhanced catalytic activity. On this foundation, a label-free electrochemical immunosensor was developed for myoglobin (Myo) assay based on the AuPtAg PHNR. Further, the built sensor exhibited fast and ultrasensitive responses in a linear range of 0.0001 ~ 1000 ng mL−1 with a low limit of detection (LOD = 0.46 pg mL−1, S/N = 3), and enabled efficient application to human serum samples with acceptable results. Consequently, the developed AuPtAg PHNR–based platform has a broad prospect in practically monitoring Myo and other biomarkers in clinics. [ABSTRACT FROM AUTHOR]

Rational design of highly efficient and durable electrocatalysts for hydrogen evolution reaction (HER) is of prime importance for renewable and sustainable energy. Herein, PtNi nanodentrites (PtNi NDs) were facilely synthesized in oleylamine (OAm) by a one-pot solvothermal method, using melamine and cetyltrimethylammonium chloride (CTAC) as co-structure-directing agents. The obtained catalyst showed superior catalytic activity and enhanced durability for HER relative to commercial Pt/C, home-made PtNi 3 nanocrystals (NCs) and Pt 3 Ni NCs both in alkaline and acidic media. The enhanced HER activities are attributed to bimetallic synergies and interface structures in PtNi NDs. This work provides an effective strategy to prepare highly efficient and durable electrocatalysts for HER. [ABSTRACT FROM AUTHOR]

[Display omitted] In the last decades, 4-nitrophenol is regarded as one of highly toxic organic pollutants in industrial wastewater, which attracts great concern to earth sustainability. Herein, atomically dispersed ternary FeCoNb active sites were incorporated into nitrogen-doped honeycomb-like mesoporous carbon (termed FeCoNb/NHC) by a two-step pyrolysis strategy, whose morphology, structure and size were characterized by a set of techniques. Further, the catalytic activity and reusability of the as-prepared FeCoNb/NHC were rigorously examined by using 4-NP catalytic hydrogenation as a proof-of-concept model. The influence of the secondary pyrolysis temperature on the catalytic performance was investigated, combined by illuminating the catalytic mechanism. The resultant catalyst exhibited significantly enhanced catalytic features with a normalized rate constant (k app) of 1.2 × 104 min-1g−1 and superior stability, surpassing the home-made catalysts in the control groups and earlier research. This study provides some constructive insights for preparation of high-efficiency and cost-effectiveness single-atom nanocatalysts in organic pollutants environmental remediation. [ABSTRACT FROM AUTHOR]

[Display omitted] Replacing precious metal catalysts with low-price and abundant catalysts is one of urgent goals for green and sustainable energy development. It is imperative yet challenging to search low-cost, high-efficiency, and long-durability electrocatalysts for oxygen reduction reaction (ORR) in energy conversion devices. Herein, three-dimensional low-cost Co 3 Fe 7 nanoparticles/nitrogen, manganese-codoped porous carbon (Co 3 Fe 7 /N, Mn-PC) was synthesized with the mixture of dicyandiamide, cobalt (II) tetramethoxyphenylporphyrin (Co(II)TMOPP), hemin, and manganese acetate by one-step pyrolysis and then acid etching. The resultant Co 3 Fe 7 /N, Mn-PC exhibited excellent durability and prominent ORR activity with more positive onset potential (E onset , 0.98 V) and half-wave potential (E 1/2 , 0.87 V) in 0.1 M KOH electrolyte, coupled with strong methanol resistance. The pyrolysis temperature and optimal balance of graphite with pyridine-nitrogen are of significance for the ORR performance. The prepared Co 3 Fe 7 /N, Mn-PC displayed excellent ORR performance over commercial Pt/C in the identical environment. It was ascribed to the uniform 3D architecture, Mn- and N-doping effects by finely adjusting the electronic structures, coupled with the synergistic catalytic effects of multi-compositions and multi-active sites. This work provides some constructive guidelines for preparation of low-cost and high-efficiency ORR electrocatalysts. [ABSTRACT FROM AUTHOR]

In this work, solid-core@porous-shell alloyed PtAg nanocrystals (PtAg NCs) were fabricated via a simple one-pot co-reduction wet-chemical method on a large scale. Diprophylline (DPP) was employed as the stabilizing agent and shape-directing agent, without any surfactant, polymer, seed or template. The products were mainly analyzed by a series of characterization technique. The hierarchical architectures had enhanced stability and improved electrocatalytic activity for hydrogen evolution reaction (HER) and glycerol oxidation reaction (GOR) in contrast with commercial available Pt/C and Pt black catalysts. For the prepared PtAg NCs catalyst, the Tafel slope is 40 mV dec −1 toward HER in 0.5 M H 2 SO 4 , coupled with the specific activity and mass activity of 77.91 mA cm −2 and 1303 mA mg −1 Pt toward GOR, respectively. [ABSTRACT FROM AUTHOR]

Herein, uniform Pt 2.6 Co 1 nanoflowers (NFs) were synthesized in oleylamine by a one-pot solvothermal method, using cetyltrimethylammonium chloride (CTAC) and glucose as the capping agent and green reducing agent. The samples were mainly characterized by transmission electron microscopy (TEM), high angle annular dark-field scanning TEM (HAADF-STEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The architectures had larger electrochemically active surface area (ECSA) of 23.84 m 2 g −1 Pt than Pt 1.2 Co 1 nanocrystals (NCs, 14.96 m 2 g −1 Pt ), Pt 3.7 Co 1 NCs (16.96 m 2 g −1 Pt ) and commercial Pt black (20.35 m 2 g −1 Pt ). And the as-obtained Pt 2.6 Co 1 catalyst displayed superior catalytic performance and better durability for hydrogen evolution reaction (HER) as compared to Pt 1.2 Co 1 NCs, Pt 3.7 Co 1 NCs, commercial 50% Pt/C and Pt black catalysts in acid and alkaline media. Meanwhile, the electrocatalytic performance of Pt 2.6 Co 1 NFs for oxygen reduction reaction (ORR) is better in acid media as compared with that in alkaline media. It indicates the great potential applications of the as-prepared catalyst in fuel cells. [ABSTRACT FROM AUTHOR]

Herein, a simple one-pot successive co-reduction method was developed for synthesis of bimetallic AuPd dendritic alloyed nanocrystals (AuPd DANCs), in which 3-aminopyrazine-2-carboxylic acid was acted as a capping agent. The products were characterized by transmission electron microscopy (TEM), high angle annular dark-field scanning TEM, X-ray diffraction, and X-ray photoelectron spectroscopy. The electrocatalytic activity and stability of AuPd DANCs were evaluated by cyclic voltammetry and chronoamperometry toward hydrazine oxidation reaction (HOR), showing the enhanced catalytic performance as compared with AuPd nanocrystals, Pd nanocrystals and commercial Pd black catalysts. Additionally, the catalytic mechanism and kinetics of HOR were further explored by linear sweep voltammetry, showing the potential applications of AuPd DANCs in fuel cells. [ABSTRACT FROM AUTHOR]

Herein, uniform core–shell Au–Pd@Pd nanocrystals (Au–Pd@Pd NCs) were prepared by a simple and eco-friendly one-step wet-chemical co-reduction method using allantoin as a structure-directing agent, without using any pre-made seed, toxic organic solvent, surfactant or polymer. Their characterizations were determined by transmission electron microscopy (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The possible growth mechanism was also discussed in details. The as-fabricated architecture showed enhanced electrocatalytic ability and stability toward ethylene glycol oxidation reaction (EGOR) as compared to Au nanocrystals and commercial Pd black catalysts in alkaline media. [ABSTRACT FROM AUTHOR]

In this work, three-dimensional trimetallic Pt–Pd–Co alloyed nanoflowers are fabricated by a facile one-pot solvothermal strategy, with the assistance of oleylamine as the solvent, surfactant, and reducing agents, along with cetylpyridinium chloride (CPC) as the co-surfactant and shape-directing agents. Their morphology and crystal structure were investigated by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning transmission electron microscope (STEM), and X-ray photoelectron spectra (XPS) in details. The respective electrochemically active surface area (ECSA) is estimated to be 32.53 m 2 g −1 , and current density is 132.91 mA cm −2 for the electrooxidation of ethylene glycol (EG). These values are much higher than those of PtPdCo nanoparticles, PtPd nanoparticles, commercial Pt black, and Pd black under the identical conditions, showing the improved catalytic activity of Pt–Pd–Co nanoflowers. The excellent performances are attributed to the specific structure and synergistic interactions of the trimetallic alloy. The as-prepared nanoflowers can serve as a promising electrocatalyst in fuel cells. [ABSTRACT FROM AUTHOR]

[Display omitted] The high-performance and durable oxygen reduction reaction (ORR) catalyst on air cathode is a key component in assembly of Zn-air batteries. Herein, three-dimensional N-doped ordered mesoporous carbon (3D N-OMC) was first prepared with silica as a template via pyrolysis with assistance of dicyandiamide as a N-doping agent, combined by full adsorption of platinum (II) acetylacetonate (Pt(acac) 2) and iron (II) phthalocyanine (FePc) via π-π interactions. After further pyrolysis of the resulting mixture, many PtFe nanoparticles were efficiently incorporated in 3D N-OMC (termed as PtFe@3D N-OMC for simplicity). Control experiments were certificated the important role of the pyrolysis temperature played in this synthesis. The resultant composite synergistically combines advantages of hierarchically accessible surfaces, highly open structure, and well-dispersed PtFe particles, which endow the PtFe@3D N-OMC with onset and half-wave potentials of 0.98 and 0.86 V in alkaline media, respectively, showing appealing catalytic activity for the ORR. Most significantly, the PtFe@3D N-OMC based Zn-air battery has a high power density of 80.57 mW cm−2 and long-term durability (220 h, 660 cycles). This work opens a new avenue for design of high-efficiency and durable ORR electrocatalysts in energy conversion and storage systems. [ABSTRACT FROM AUTHOR]

[Display omitted] To achieve commercial applications of green fuel cells and rechargeable metal-air batteries, rational design and synthesis of low-cost, high-efficiency and ultra-stable transition metal-based electrocatalysts are of significant importance for alkaline oxygen reduction reaction (ORR). In this work, iron-cobalt (FeCo) nanoparticles-capped carbon nano-tubes/-porous nitrogen-doped honeycombed carbon composite (FeCo-CNTs/NHC-800) is synthesized by a water-regulated and bioinspired one-step pyrolysis method at 800 °C, where l -histidine behaves as the C and N sources combined by working as a chelating agent of Fe/Co. The formation mechanism is discussed by adjusting the pyrolysis temperature and water amount. The resultant FeCo-CNTs/NHC-800 exhibits a positive onset potential (E onset = 1.091 V) and half-wave potential (E 1/2 = 0.88 V), showing promising ORR activity, outperforming home-made controls and many lately reported catalysts. The hierarchically porous honeycombed structures have fascinating open porous spaces for fast diffusion of active species, large specific surface area, high conductivity, and stable sites for anchoring FeCo nanoparticles (NPs). Moreover, the N -doped carbon nanotubes coupling with homogeneous FeCo NPs greatly improve the catalytic activity and stability of ORR. This work provides some valuable insights to prepare hierarchical, reliable, and high-efficiency carbon-based ORR catalysts for new energy-correlated devices. [ABSTRACT FROM AUTHOR]

In this work, a simple and facile strategy was developed for preparation of well-defined Au-Pd bimetallic alloyed nanoparticles uniformly supported on reduced graphene oxide nanosheets (RGOs) under solvothermal conditions. The detailed morphology, crystal structure, and composition were well characterized by (high-resolution) transmission electron microscopy (TEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The as-prepared nanocomposites displayed the enhanced catalytic ability, better stability, and good methanol tolerance towards oxygen reduction reaction (ORR) in alkaline media, compared with commercial Pd black and RGOs (reduced by NaBH4) catalysts. The as-developed method could be applied for synthesis of other morphology-controlled bimetallic electrocatalysts. [ABSTRACT FROM AUTHOR]

[Display omitted] • The Co NPs/NS-CNTs derived from ZIF-67 was prepared by a simple pyrolysis method. • The hybrid catalyst created abundant active sites, showing highly large surface area. • The catalyst displayed excellent catalytic activity and stability for the ORR. • The assembled Zn-air battery offered high power density and long-term durability. It remains a challenge for efficient and facile synthesis of promising non-noble metal electrocatalysts with outstanding properties. This work reported a simple pyrolysis method to prepare cobalt nanoparticles/nitrogen, sulfur-codoped ultrathin carbon nanotubes (Co NPs/N,S-CNTs) with metal organic frameworks (cobalt 2-methylimidazole, ZIF-67), melamine, polyvinylpyrrolidone (PVP) and thiourea. The prepared catalyst exhibited superior catalytic activity towards oxygen reduction reaction (ORR) such as the more positive onset potential of 0.96 V, half-wave potential of 0.86 V and smaller Tafel slope of 67.9 mV dec−1, outperforming those of commercial Pt/C. Furthermore, the Co NPs/N,S-CNTs based Zn-air battery not only showed good cycling performance, but also displayed a notable peak power density (153.8 mW cm−2) and large open-circuit voltage (1.433 V). This study provides some valuable guidelines for synthesizing advanced electrocatalysts in renewable energy techniques. [ABSTRACT FROM AUTHOR]

In pursuit of advanced nanocatalysts with multifunctionality, cost-effectiveness and durability for water splitting and zinc-air batteries, we unveil a novel strategy by combination of electrochemically etched Nb 4 C 3 T x -MXene nanosheets with Fe-N-C single-atom catalyst. The resultant Fe-N-C/Nb 4 C 3 T x demonstrates exceptional electrocatalytic performances for the ORR (E 1/2 = 0.911 V), OER (η 10 = 1.52 V), and HER (η 10 = 91 mV) in the alkaline media. Besides, the catalyst shows excellent application in water splitting electrolyzer, only requiring 1.58 V for a current density of 10 mA cm−2. Further, the Fe-N-C/Nb 4 C 3 T x assembled battery displays an open-circuit voltage of 1.51 V, a higher peak power density (136 mW cm−2), a narrower polarization gap (0.85 V), and remarkable stability (660 cycles over 220 h), surpassing the Pt/C + RuO 2 based counterpart. Our study integrates DFT calculations to guide the catalyst design, laying the foundation for development of reliable and effective trifunctional catalysts in advanced energy-related systems. [Display omitted] • Nb 4 C 3 T x -MXene sheets with self-assembled Fe-N-C single-atom catalyst were prepared. • The Fe-N-C/Nb 4 C 3 T x showed highly efficient catalytic activities for ORR, OER and HER. • The trifunctional catalyst was employed in water splitting and Zn-air battery. • Theoretical calculations further confirmed the active sites of the catalysts. [ABSTRACT FROM AUTHOR]

Alkaline hydrogen evolution reaction (HER) electrocatalysts with high catalytic activity and long-term durability are of significance for sustainable energy applications. Herein, we prepared trimetallic PtNiCo hollow alloyed 3D multipods (HAMPs) with rough surfaces by an effective one-pot solvothermal strategy coupled with acid etching, as evidenced by a series of characterizations. By virtue of the trimetals and unique structures, the PtNiCo HAMPs exhibited excellent HER performance in 1.0 M KOH electrolyte with a low overpotential (η, 20 mV) and small Tafel slope (46.3 mV dec−1), superior to homemade PtNi HAMPs, PtCo nanocrystals (NCs) and commercial Pt/C catalysts. This study provides some constructive guidelines for synthesis of advanced hollow multimetallic catalysts in energy systems. [ABSTRACT FROM AUTHOR]

Developing highly active and durable catalyst is of pivotal importance in fuel cells, owing to excessive consumption of fossil fuels. Herein, porous dendritic PtRuPd nanospheres (PtRuPd NSs) were synthesized by a facile hexadecylpyridinium chloride (HDPC)-mediated one-pot aqueous method with ascorbic acid (AA) as the reducing agent. The as-obtained PtRuPd NSs displayed high-efficient catalytic activity and durability for ethylene glycol oxidation reaction (EGOR) and oxygen reduction reaction (ORR). It exhibited enlarged mass activity (MA, 1.368 A mg−1) compared to commercial Pt/C (1.100 A mg−1) for EGOR. Besides, the onset potential (E onset , 0.930 V) and half-wave potential (E 1/2 , 0.852 V) of PtRuPd NSs were more positive relative to homemade PtPd NSs (0.905 and 0.840 V), PdRu NSs (0.895 and 0.839 V), and commercial Pt/C (0.910 and 0.822 V) toward ORR. This work provides some valuable guidelines for producing novel trimetallic nanocatalysts in fuel cells. [ABSTRACT FROM AUTHOR]

High-entropy nanomaterials are regarded as the new research hotspots for their intriguing "cocktail effect". Herein, self-supported PtPdMnCoFe high-entropy alloy with nanochain-like internetworks (PtPdMnCoFe HEAINN) were synthesized by a one-pot co-reduction method, where newly-generated H 2 bubbles served as dynamic template, as identified by a series of characterizations. The high-entropy architecture was certificated effectiveness for reduction of H 2 O 2 , which was explored as signal amplifier to develop a novel label-free electrochemical amperometric immunosensor for ultrasensitive determination of biomarker neuron-specific enolase (NSE). In the optimized analytical surroundings, the as-fabricated sensor showed a broad linear range of 0.1 pg mL–1 to 200 ng mL–1 for immunoassay of NSE with a low limit of detection (LOD = 0.0036 pg mL–1, S/N = 3), coupled by its quantification in human serum samples with satisfactory results. This work provides valuable guidance for potential applications of high-entropy alloyed materials in biosensors and immunoanalysis. [Display omitted] • The high entropy alloys were successfully applied in electrochemical immunosensors firstly. • PtPdMnCoFe HEAINN was synthesized by a facile one-pot aqueous co-reduction strategy. • The HEAINN provided large specific surface area, attractive electronic effects and high catalytic activity. • The resultant immunosensor displayed excellent analytical preference for biomarker NSE. [ABSTRACT FROM AUTHOR]

Graphical abstract Abstract Herein, highly branched Pt@Ag core-shell nanoparticles (Pt@Ag NPs) were fabricated by a facile one-pot wet-chemical approach, where poly(ethyleneimine) (PEI) served as structure-directing and capping agents. Their structure, morphology and composition were mainly characterized by a set of techniques. And their growth mechanism was discussed in some detail. The prepared catalyst exhibited remarkable enhancement in catalytic activity of 4-nitrophenol (4-NP) reduction as a proof-of-concept application, surpassing commercial Pt black and home-made Ag NPs catalysts. Also, the as-obtained catalyst showed superior stability without sacrificing the catalytic activity. These observations endow the catalyst possibility for practical applications in nitrophenols environmental remediation. [ABSTRACT FROM AUTHOR]

[Display omitted] • FeCo DSAs/ N -CNAs was facilely prepared by a glucose-assisted pyrolysis method. • FeCo DSAs/ N -CNAs showed high-efficiency ORR activity and prominent stability. • The as-assembled Zn-air battery showed high open-circuit voltage, large power density and long-term durability. • The excellent catalytic activity resulted from the synergistic catalytic effect of the Fe/Co sites. Dual-metal single-atom catalysts (DSAs) exhibit excellent electrocatalytic properties, holding great promise in energy conversion and storage fields. Their rational design and synthesis are realized by optimizing the types of supporting substrate or regulating the coordination microenvironment. Herein, FeCo DSAs supported on N -doped carbon nanotube aerogels (FeCo DSAs/ N -CNAs) were facilely fabricated by a glucose-assisted atomic regulation pyrolysis approach. The morphology and structure were characterized by a series of techniques. The influences of the pyrolysis temperature and types of the metal precursors were carefully investigated, coupled by elaborating the formation mechanism. The resulting FeCo DSAs/ N -CNAs catalyst shows a positive onset potential (E onset = 1.075 V) and half-wave potential (E 1/2 = 0.907 V) for oxygen reduction reaction (ORR) in a 0.1 M KOH solution, outperforming those of commercial Pt/C. The obtained catalyst is further exploited for establishing rechargeable Zn-air battery, which shows a larger peak power density of 86.7 mW cm−2 and a longer cycle stability over 144 h. These findings identify low-cost FeCo DSAs/ N -CNAs as promising electrocatalysts for advanced rechargeable Zn-air batteries. [ABSTRACT FROM AUTHOR]

Ionic liquids as templates or directing agents have attracted great attention for shaping-modulated synthesis of advanced nanomaterials. In this work, reduced graphene oxide supported uniform core-shell Au@Pt nanoparticles (Au@Pt NPs/rGO) were fabricated by a simple one-pot aqueous approach, using N -methylimidazolium-based dicationic ionic liquid (1,1-bis(3-methylimadazoilum-1-yl)butylene bromide, [C 4 (Mim) 2 ]2Br) as the shape-directing agent. The morphology evolution, structural information and formation mechanism of Au@Pt NPs anchored on rGO were investigated by a series of characterization techniques. The obtained nanocomposites displayed superior electrocatalytic features toward hydrogen evolution reaction (HER) and oxygen reduction reaction (ORR) compared with commercial Pt/C catalyst. This approach provides a novel route for facile synthesis of nanocatalysts in fuel cells. [ABSTRACT FROM AUTHOR]

Herein, prickly platinum-palladium core-shell nanocrystals (Pt@Pd NCs) were prepared by a facile one-pot aqueous method, only taking sodium pyrrolidone carboxylate (PCA-Na) as the structure director and stabilizing agent. The products were mainly characterized by microscopic analysis, X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS), followed by discussing the formation mechanism in details. The electrochemical characterizations were examined by cyclic voltammetry (CV), linear sweep voltammetry (LSV) and chronoamperometry (CA). The results revealed that the prepared architectures had the biggest current density (58.4 mA cm –2 ) for ethylene glycol oxidation, which is 3.5-fold, 1.2-fold, 2.3-fold and 2.4-flod enhancement relative to those of home-made single Pt nanoparticles (NPs) and Pd NPs, commercial Pt black and Pd black catalysts, respectively. Also, the obtained Pt@Pd NCs showed improved catalytic activity and stability towards glycerol oxidation and hydrogen evolution reactions compared to the references. [ABSTRACT FROM AUTHOR]

Herein, self-supported hierarchical AuPd alloyed interconnected nanowire networks (AuPd NCNs) were fabricated by a one-pot co-reduction method. Theophylline was acted as the capping and structure-directing agents. The product was mainly characterized by a series of techniques such as transmission electron microscopy (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The hierarchical nanostructures had the enlarged electrochemically active surface area (EASA), and the enhanced catalytic activity toward formic acid oxidation reaction (FAOR) and strengthened poisoning tolerance for poisoning CO-like intermediates by cyclic voltammetry and chronoamperometry, which outperformed commercial Pd black catalyst. This strategy supplies a simple and general method for mass preparation of AuPd NCNs with potential applications in fuel cells. [ABSTRACT FROM AUTHOR]

A simple solvothermal method was developed to prepare N-doped reduced graphene oxide supported homogeneous PtCo nanodendrites (PtCo NDs/N-rGO), where ethylene glycol (EG) served as the reducing agent and the solvent, and linagliptin as the structure-directing and stabilizing agent for PtCo NDs and dopant for rGO, respectively. Controlled researches showed that the dosage of linagliptin and the ratios of the two metal precursors were important in the current synthesis. The PtCo NDs/N-rGO nanocomposite exhibited higher catalytic activity towards the reduction of 4-nitrophnol (4-NP) in contrast with the referenced Pt 1 Co 3 NCs/N-rGO, Pt 3 Co 1 NCs/N-rGO and commercial Pt/C catalysts. More importantly, the constructed catalyst exhibited the superior stability without sacrificing the catalytic activity, showing great prospect for the reduction of 4-NP in practice. [ABSTRACT FROM AUTHOR]

Theophylline as a naturally alkaloid is commonly employed to treat asthma and chronic obstructive pulmonary disorder. Herein, a facile theophylline-assisted green approach was firstly developed for synthesis of PtAu nanospheres/reduced graphene oxide (PtAu NSs/rGO), without any surfactant, polymer, or seed involved. The obtained nanocomposites were applied for the catalytic reduction and removal of highly toxic chromium (VI) using formic acid as a model reductant at 50 °C, showing the significantly enhanced catalytic activity and improved recyclability when compared with commercial Pt/C (50%) and home-made Au nanocrystals supported rGO (Au NCs/rGO). It demonstrates great potential applications of the catalyst in wastewater treatment and environmental protection. The eco-friendly route provides a new platform to fabricate other catalysts with enhanced catalytic activity. [ABSTRACT FROM AUTHOR]

[Display omitted] • Pt-PtFe/ N -CNFs were prepared by one-step pyrolysis. • The 3D porous carbon structures had large surface area and high conductivity. • The Pt-PtFe/ N -CNFs showed high catalytic activity for N 2 H 4 and BPA oxidation. • The developed sensor revealed high analytical performances for N 2 H 4 and BPA even in actual samples. It is still challenging for synthesis of advanced nanomaterials and explores their electrocatalytic detection of hydrazine (N 2 H 4) and bisphenol A (BPA). Herein, Pt-PtFe nanoparticles/three-dimensional (3D) porous N -doped carbon nanoflowers (Pt-PtFe/ N -CNFs) were successfully prepared by high-temperature pyrolysis. The structures and properties of the nanocomposite were strictly investigated by various characterization techniques. The Pt-PtFe/ N -CNFs displayed high-efficiency electrocatalytic activity for oxidation of N 2 H 4 and BPA. Under the optimal conditions, the Pt-PtFe/ N -CNFs based sensor exhibited the wide linear ranges: 0.5–559.5 μM and 559.5–2659.5 μM for detection of N 2 H 4 with a limit of detection (LOD) of 0.19 μM (S/N = 3), coupled with a broad scope of 0.3–70 μM and a LOD of 0.043 μM for BPA. The developed sensor has promising applications in environmental and industrial samples. [ABSTRACT FROM AUTHOR]

Herein, a facile 4-aminopyridine-assisted one-pot approach was developed for synthesis of bimetallic PdAu alloyed nanowires (NWs) on a large scale, without using any pre-made seed, surfactant or polymer. Their formation mechanism was discussed based on the oriented attachment growth. The as-synthesized architectures have enlarged electrochemically active surface area and enhanced mass activity relative to commercial Pd black catalyst, revealing the improved catalytic activity, durability, and tolerance to carbonaceous species poisoning toward methanol oxidation reaction (MOR). This is attributed to their unique wire-like nanostructures, along with the synergetic effects between Pd and Au. [ABSTRACT FROM AUTHOR]

The construction and design of nanomaterials are important for improving their performance. Here we present a simple one-pot wet-chemical method for the preparation of alloyed Pd-Cu nanowires using octylphenoxypolyethoxyethanol (NP-40) as structure-directing and stabilizing agents. The obtained nanocrystals display outstanding catalytic activity for ligand-free Suzuki cross coupling reaction under mild conditions, and can be easily recovered and reused for at least 5 consecutive cycles without showing significant loss of catalytic activity. [ABSTRACT FROM AUTHOR]

Amino acids with intrinsic affinity to metallic ions can be employed for controllable synthesis of metal nanocrystals with tunable size and morphology, as well as less toxicity. In this work, L- histidine was exploited as a structure-director for in situ controlled growth of bimetallic PtPd alloyed nanoflowers on reduced graphene oxide (RGO-PtPd nanoflowers) by a simple one-pot aqueous approach at room temperature. There was no seed, template, special apparatus or organic solvent involved in the synthetic process. The as-synthesized nanocomposites displayed improved electrocatalytic ability and durability for ethylene glycol oxidation reaction (EGOR) as compared to Pt-RGO, Pd-RGO, commercial PtRu/C, Pt black and Pt/C catalysts. [ABSTRACT FROM AUTHOR]

Rambutan-like ZnO hierarchical hollow microspheres (ZnO HHMs) were constructed under hydrothermal conditions, using carboxyl methyl starch (CMS) as a soft template. The resulting products were characterized by using X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The experimental parameters and growth mechanism of rambutan-like ZnO HHMs were discussed in some detail. The as-prepared samples displayed improved photocatalytic activity for the degradation of rhodamine B under ultraviolet (UV) irradiation. [ABSTRACT FROM AUTHOR]

In this work, a simple, rapid and facile one-pot wet-chemical co-reduction method is developed for synthesis of bimetallic Au–Pt alloyed nanochains supported on reduced graphene oxide (Au–Pt NCs/RGO), in which caffeine is acted as a capping agent and a structure-directing agent, while no any seed, template, surfactant or polymer involved. The as-prepared nanocomposites display enlarged electrochemical active surface area, significantly enhanced catalytic activity and better stability for methanol and ethylene glycol oxidation, compared with commercial Pt–C (Pt 50 wt%), PtRu–C (Pt 30 wt% and Ru 15 wt%) and Pt black. [ABSTRACT FROM AUTHOR]

Abstract: In this report, a simple and facile solvothermal method is developed for fabrication of platinum–ruthenium (PtRu) nanodendrites supported on reduced graphene oxide (PtRu-RGO) in the ethylene glycol (EG) system, using hexadecylpyridinium chloride (HDPC) as a shape-directing agent. The as-prepared nanocomposites show the superior catalytic activity and better stability towards EG oxidation, compared with RGO-supported Pt nanoparticles and commercial PtRu/C (Pt 30 wt. %, Ru 15 wt. %) catalysts. This strategy may open a new route to design and prepare advanced electrocatalysts in direct EG fuel cells. [Copyright &y& Elsevier]

Abstract: Well-defined platinum–palladium@palladium core–shell nanospheres (PtPd@Pd NSs) are synthesized by a facile one-pot solution approach using N-methylimidazole and poly(vinyl pyrrolidone) (PVP) as directing and capping agents, respectively, without using any seed, template, or organic solvent. The coexistence of the precursors, N-methylimidazole, PVP, and reaction temperature has great effects on the final morphology. Thus-prepared nanocomposites display an improved electrocatalytic activity for oxygen reduction reaction (ORR) in acidic media, methanol and ethylene glycol oxidation reaction in alkaline media, compared with Pt nanoparticles, Pd nanoparticles, commercial Pt black and Pd black catalysts. This method may direct a general orientation for shape control synthesis of functional bimetallic nanocrystals as promising electrocatalysts in direct alcohol fuel cells (DAFCs). [Copyright &y& Elsevier]

Abstract: Well-defined core–shell gold–palladium@palladium nanocrystals (AuPd@Pd) are facilely prepared by a simple and green wet-chemical method at 25 °C. A Good's buffer, 2-[4-(2-hydroxyethyl)-1-piperazinyl] ethanesulfonic acid (HEPES), is used as a reducing agent and a shape-directing agent, while there is no template, seed, organic solvent, or surfactant involved. The AuPd@Pd nanocrystals are uniformly dispersed on graphene nanosheets by ultrasonication, resulting in the formation of graphene supported AuPd@Pd (G-AuPd@Pd). The as-prepared nanocomposites exhibit the improved catalytic activity, good tolerance, and better stability for oxygen reduction reaction (ORR) and methanol oxidation reaction (MOR) in alkaline media, compared with the G-Pd and commercial Pd black catalysts. The as-developed method may provide a promising pathway for large-scale fabrication of AuPd-based catalysts. [Copyright &y& Elsevier]

Highlights: [•] Well-defined Pd nanochains were quickly synthesized by a simple one-pot wet-chemical reduction method. [•] OP-10 is used as a growth directing agent for the formation of the Pd nanochains. [•] The Pd nanochains displayed the enhanced electrocatalytic performance for formic acid oxidation in acidic media. [ABSTRACT FROM AUTHOR]

Highlights: [•] Well-defined flower-like Pt arrays were prepared via one-step electrodeposition, assisted with urea as a growth directing agent. [•] This method is simple, facile, and controllable, without using any template, seed or surfactant. [•] The Pt arrays show an enhanced electrocatalytic activity toward ethylene glycol and methanol oxidation. [Copyright &y& Elsevier]

Highlights: [•] Hierarchical wheat-like Au–Pd heterostructures were prepared. [•] This method was simple, facile, and controllable. [•] l-Glutamic acid was important in the formation of the superstructures. [•] This material showed high electrocatalytic activity toward methanol oxidation. [ABSTRACT FROM AUTHOR]

Highlights: [•] Functionalized RGO was obtained by previously coating with PDA. [•] Pt nanoparticles were uniformly immobilized on the PDA/RGO nanocomposites. [•] The as-prepared composites have high electrochemically active surface area. [•] The Pt/PDA/RGO composites show high electrocatalytic activity. [ABSTRACT FROM AUTHOR]

Highly efficient, low-cost, and long-term stable catalysts are of great significance as promising alternatives to noble metal-based catalysts for oxygen reduction reaction (ORR), oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) in energy-related devices. Herein, CoFe decorated bougainvillea-like N-doped carbon nanoflowers (CoFe-NCNFs) are synthesized through a one-step aminouracil-assisted pyrolysis strategy. Benefit from the abundant active sites from the flower-like structures, along with synergistic effect between multi-compositions, the catalyst displays distinct improvement on the ORR with the more positive onset potential (E onset = 1.06 V) and half-wave potential (E 1/2 = 0.85 V), coupled with the small overpotential (η) of 323 mV and 212 mV at 10 mA cm−2 for OER and HER, respectively. In view of the trifunctional properties, a rechargeable Zn–air battery is constructed by self-assembly, possessing large power density (116.1 mW cm−2), small voltage gap (0.865 V at 5 mA cm−2), and superior durability for 110 h. Also, the catalyst demonstrated excellent catalytic activity and stability in water electrolysis (η = 1.65 V at 10 mA cm−2 for 20 h). This research offers a breakthrough in developing advanced multifunctional non-precious metal-based electrocatalysts in metal–air batteries, water electrolysis, and other energy-correlated devices. [Display omitted] • CoFe-NCNFs were fabricated by a facile pyrolysis method. • The unique structure offers enlarged specific active area and improved stability. • Multi-component synergetic effect brings out trifunctional catalytic activities. • The catalyst performs well in Zn–air battery and water electrolysis. [ABSTRACT FROM AUTHOR]

[Display omitted] • The AuPtPd FNDs were obtained by a one-pot thymine-mediated aqueous method. • The unique structures had large specific surface area, ultimately increasing the loading capacity of the antibody. • Such architectures displayed high catalytic activity to improve the electrochemical signals of K 3 [Fe(CN) 6 ]. • The immunosensor showed excellent analytical performances in the assay of cTnI. Enhancement in the signals of electrochemical immunosensors via advanced nanomaterials is beneficial for developing immunoassay of cardiac troponin I (cTnI) with high sensitivity and selectivity. By virtue of K 3 [Fe(CN) 6 ] as a signal probe, an advanced label-free electrochemical immunosensor was fabricated for ultrasensitive detection of cTnI with trimetallic alloyed AuPtPd porous fluffy-like nanodendrites (AuPtPd FNDs), followed by assembly of the antibody (Ab). By virtue of the structural advantages, electronic effects and synergetic catalysis of the trimetals, such nanostructures showed large specific surface area to increase the loading of the cTnI Ab and amplify the electrochemical signals of the probe. The sensor displayed a wide linear range (0.01 ~ 100.0 ng mL−1) and a low detection limit (LOD = 3 pg mL−1) under the optimal conditions, which showed great potential for detecting cTnI in serum samples. Furthermore, this biosensor provides an effective detection platform for analysis of other cardiac markers in practical samples. [ABSTRACT FROM AUTHOR]

• The PdCuPt HZBUS were prepared by a one-pot wet-chemical approach. • PEO and KBr performed as co-directing agents in the synthesis. • The PdCuPt HZBUS provide enlarged surface area and more active sites. • The nanocatalyst displayed high activity and long-term stability for FAOR. Hierarchically branched multi-metallic nanoassembles are promising catalysts extensively used in catalytic fields because of their unique structural features and multicompositions advantages. Herein, three-dimensional (3D) hierarchical zigzag-branched urchin-like PdCuPt superstructures (HZBUS) were prepared by a one-pot wet-chemical method, where polyethylene oxide (PEO) and KBr served as directing agents. The specific architectures provided abundant active sites highly available for reactants, in turn showing highly enlarged electrochemically active surface area (16.79 m2 g−1 Pd). The as-obtained PdCuPt HZBUS displayed dramatically enhanced catalytic activity and improved long-term durability for formic acid oxidation reaction (FAOR), surpassing homemade PdCu nanoparticles (NPs), commercial Pd black and Pt/C catalysts. This work offers a new strategy for construction of advanced multimetallic electrocatalysts with charming superstructures and high-efficient performances in fuel cells. [ABSTRACT FROM AUTHOR]

• Hierarchically multi-branched PdRuCu NAs were prepared by a one-step aqueous method. • NP-40 and NaBr as co-directing agents had synergistic effects in the formation of the specific architectures. • The hierarchically multi-branched nanostructures had the large ECSA. • The PdRuCu NAs showed the superior catalytic activity and stability towards EOR and EGOR. Shaped-controlled synthesis of high-efficiency electrocatalysts towards ethanol oxidation reaction (EOR) and ethylene glycol oxidation reaction (EGOR) is important for development of alcohol alkaline fuel cells. Herein, one-step aqueous method was developed for constructing hierarchically multi-branched PdRuCu nanoassemblies (NAs) under the guidance of octylphenoxypolyethoxyethanol (NP-40) and NaBr. The as-obtained PdRuCu NAs exhibited dramatically enhanced electrocatalytic activity and improved stability for EOR and EGOR in alkaline solution. The mass/specific activity of the as-prepared catalysts for EOR (1.16 A mg−1 Pd /3.78 mA cm−2) and EGOR (1.29 A mg−1 Pd /4.19 mA cm−2) were steeply higher than those of commercial Pd black (0.17 A mg−1 Pd /1.81 mA cm−2; 0.21 A mg−1 Pd /2.27 mA cm−2), respectively. This work would provide some valuable insights for synthesis of advanced polymetallic electrocatalysts in fuel cells. [ABSTRACT FROM AUTHOR]