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Platinum-ruthenium (PtRu) electrocatalyst is traditionally used in the direct methanol fuel cells (DMFCs) as anodic electrocatalyst since Ru promotes the CO anti-poisoning of the neighbored Pt; however, Ru is dissolvable in acid media resulting in low stability of PtRu electrocatalyst. Here, we report a facile method to decelerate the Ru dissolution and to enhance the CO anti-poisoning by coating PtRu nanoparticles with cerium oxide (CeO 2 ). C/PtRu@CeO 2 exhibits only 30% loss in electrochemical surface area (ECSA) after 4200 potential cycles; in contrast, ECSA loss reaches 55% for the bare PtRu electrocatalyst. Meanwhile, the methanol oxidation reaction (MOR) activity is 2.8 fold higher by comparison with bare electrocatalyst. The enhanced MOR activity is attributed to the high oxygen storage capacity of CeO 2 promoting the complete methanol oxidation. And the CO stripping voltammetry result shows that the CO oxidation peaks of C/PtRu@CeO 2 negatively shift by 60 mV and 250 mV before and after stability test compared to those of C/PtRu electrocatalyst, respectively, suggesting an enhanced CO anti-positioning for C/PtRu@CeO 2 . Moreover, the fuel cell performance of C/PtRu@CeO 2 reaches 49 mW cm −2 ; while, power density of C/PtRu is 45 mW cm −2 at 80 °C. [ABSTRACT FROM AUTHOR]

We report herein a means of transforming TiO 2 nanotube arrays (TNAs) from an amorphous state to an anatase crystal state (denoted as ∗ TNAs), and present a single-step synthetic route for preparing CdS quantum dots (CdS QDs) as well as reduced graphene oxide (rGO) through gamma-ray irradiation. The as-prepared ∗ TNAs, CdS QDs, and rGO, which had all been subjected to gamma-ray irradiation, were then assembled together to produce the desired heterojunction (denoted as CdS QDs/rGO- ∗ TNAs). X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), ultraviolet/visible diffuse-reflectance spectroscopy (UV/Vis DRS), Fourier-transform infrared spectroscopy (FTIR), micro-Raman spectrometry (RS), atomic force microscopy (AFM), and X-ray photoelectron spectroscopy (XPS) have been applied to characterize the appearance and performance of this photocatalyst. The photocatalytic activity of CdS QDs/rGO- ∗ TNAs towards ethylene degradation has been measured by placing it in a simulated cold-storage environment, the temperature and humidity of which were set at about 3 ± 1 °C and 75–90%, respectively. The results showed that the rate constant ( K ) of ethylene degradation could reach up to 1.07 × 10 −3  min −1 with CdS QDs/rGO- ∗ TNAs, as compared to 2.30 × 10 −4  min −1 with ∗ TNAs and 6.25 × 10 −4  min −1 with CdS QDs- ∗ TNAs, indicating that the constructed CdS QDs/rGO- ∗ TNAs constitutes a promising photocatalyst for ethylene removal in a cold storage environment. [ABSTRACT FROM AUTHOR]

Highlights: [•] The nanosized pit-like film is formed on aluminum after chemical etch by NaOH solution. [•] High hydrophobic films were prepared by immersed etched aluminum in an ethanol solution containing stearic acid. [•] Aluminum shows a low friction with long wear life by combining chemical etch and stearic acid overcoat. [ABSTRACT FROM AUTHOR]

• Flower-like ZnIn 2 S 4 coupled with black phosphorus (BP) as efficient photocatalyst. • BP and photo-deposited Pt played a synergistic role in enhancing photocatalytic H 2 evolution. • 0.5%Pt/0.5%BP/ZnIn 2 S 4 showed the best H 2 production efficiency at 1278 μmol/g/h. • Superior recycling stability of more than 4 cycles for solar hydrogen evolution. To make persistent efforts at enhancing hydrogen evolution driven by solar energy, this work, for the first time, had introduced flower-like ZnIn 2 S 4 coupled with black phosphorus (BP) as efficient photocatalyst for hydrogen evolution with photo-deposited Pt assisted under visible light irradiation. The hydrogen evolution efficiency of BP, ZnIn 2 S 4 , 0.5%BP/ZnIn 2 S 4 , 0.5%Pt/BP, 0.5%Pt/ZnIn 2 S 4 and 0.5%Pt/0.5%BP/ZnIn 2 S 4 photocatalysts were successively conducted and results showed that both BP and Pt played an important role in enhancing the photocatalytic hydrogen evolution rate. Therefore, the ternary 0.5%Pt/0.5%BP/ZnIn 2 S 4 composite exhibited the strongest hydrogen production efficiency at 1278 μmol/g/h, about 10 times higher than that of pristine ZnIn 2 S 4 (131 μmol/g/h) and represented a highly stable characteristic after suffering four recycles. The promoting hydrogen evolution of ternary photocatalyst could be ascribed to the unique bandgap and larger two-dimensional plane structure of BP, which provided abundant landing sites for the anchor of flower-like ZnIn 2 S 4 , thus leading to a well-inhibited recombination and efficient separation of photogenerated electrons and hole pairs between ZnIn 2 S 4 and BP. The remarkable photocatalytic hydrogen evolution performance and prominent stability all indicated that 0.5%Pt/0.5%BP/ZnIn 2 S 4 was a promising photocatalyst candidate for solar hydrogen production. [ABSTRACT FROM AUTHOR]

• Ultra-small Ag decorated on g-C 3 N 4 photocatalyst was facilely prepared. • Strong interaction between Ag+ and cyano group promoted the fabrication. • Ag/g-C 3 N 4 -Pre exhibited superior photocatalytic performance. • Photogenerated electrons and superoxide free radicals were responsible for mechanism. This work reported a facile method for the synthesis of ultra-small Ag on g-C 3 N 4 photocatalyst (donated as Ag/g-C 3 N 4 -Pre) via strong interaction between Ag+ and cyano group in monocyanamide. The Ag/g-C 3 N 4 -Pre photocatalyst exhibited superior performance both in photocatalytic degradation of pollutants and water splitting hydrogen production compared with that Ag/g-C 3 N 4 -Post photocatalyst derived by traditional photo-deposition method. Meanwhile, the characterization of prepared photocatalyst was correspondingly carried out and the mechanism responsible for the enhancement of photocatalytic activity using Ag/g-C 3 N 4 -Pre photocatalyst was discussed as well. [ABSTRACT FROM AUTHOR]

We report the preparation of photodynamic materials from electrospun nanofibers of P(MMA -co- MAA) co-polymer that were doped with montmorillonite (MMT), and further functionalized with the cationic photosensitizer methylene blue (MB). The resultant composite nanofibers were characterized by spectroscopic (infrared, UV − vis, fluorescence) and physical (SEM/TEM, gravimetric) methods. Addition of MMT (0–6 wt%) in the electrospinning process increased the adsorption of the methylene blue photosensitizer from 21.5 mg (67.1 μmol)/g P(MMA -co- MAA) parent copolymer to 30.0 mg (93.8 μmol)/g P(MMA -co- MAA)/MMT-6 composite nanofibers. The MB-decorated P(MMA -co- MAA)/MMT-6 composite nanofibers showed a 99.997% (4.8 log units) and 97% (1.8 log units) reduction in CFU/mL against Staphylococcus aureus (ATCC-6538) and Escherichia coli strain 8099, respectively, after visible light illumination (LED lamp, 30 min, 35 ± 5 mW/cm 2 ), demonstrating that the increased photosensitizer loading attributable to MMT doping led to a 1–2 log unit increase in photodynamic inactivation efficacy over the non-doped MB-decorated P(MMA -co- MAA) parent copolymer (99.9% and 84% reduction for S. aureus and E. coli , respectively). The results demonstrate that MMT and similar additives may be a universal method for increasing the adsorption capacity of cationic photosensitizers in electrospun nanofibers, thereby generating materials with improved photodynamic inactivation efficacy without significantly changing the fiber morphology, cost, or ease of production. [ABSTRACT FROM AUTHOR]

Ni 2 CoS 4 @(NiCo)Se 2 bimetallic selenides with core–shell heterostructure in-situ generated on Ni 2 CoS 4 nanorods arrays for high performance supercapacitors. [Display omitted] • Ni 2 CoS 4 @(NiCo)Se 2 composites with the core–shell structure are prepared by simple hydrothermal and in-situ selenization methods. • The synthesized electrode material exhibits good conductivity and a large specific surface area. • The assembled device has a high energy density (53 Wh kg−1) and power density (480 W kg−1). • Two assembled all-solid-state ASCs can light a 2.5 V LED lamp for 11 min. In this paper, Ni 2 CoS 4 @(NiCo)Se 2 /NF core–shell structural nanocomposites are successfully prepared on nickel foam (NF) substrates through a convenient hydrothermal method and tube furnace calcination. Firstly, NiCo 2 O 4 /NF is acquired by a one-step simple hydrothermal method and one-step tube furnace calcination, then it is sulfidated via a one-step hydrothermal method, and finally selenized by stirring to obtain Ni 2 CoS 4 @(NiCo)Se 2 /NF. The results show that in the three-electrode test, the specific capacitance of the Ni 2 CoS 4 @(NiCo)Se 2 electrode is able to reach 6054 mF·cm−2 at a current density of 10 mA·cm−2. The excellent performance of Ni 2 CoS 4 @(NiCo)Se 2 /NF nanocomposites is supposed to give rise to the bimetallic synergistic effect, as well as the unique core–shell structure of its surface-loaded nanosheets. In addition, all-solid-state asymmetric supercapacitors (ASCs) are composed of activated carbon (AC) as the anode and Ni 2 CoS 4 @(NiCo)Se 2 /NF as the cathode. The prepared Ni 2 CoS 4 @(NiCo)Se 2 /NF//AC ASC devices reach an energy density of 53 Wh kg−1 at a power density of 480 W kg−1. Simultaneously, Ni 2 CoS 4 @(NiCo)Se 2 /NF//AC ASC device has an excellent specific capacitance of 149.06F g−1 at a current density of 0.6 A/g and a capacitance retention rate of 84.0 % after 10,000 electrochemical cycles, which proves its good cycling stability. Impressively, two Ni 2 CoS 4 @(NiCo)Se 2 /NF//AC ASC devices connected in series can light up a 2.5 V LED lamp and continue to illuminate it for 11 min. Our results show that Ni 2 CoS 4 @(NiCo)Se 2 /NF nanocomposites with core–shell structures have great application potential in energy storage devices. [ABSTRACT FROM AUTHOR]

Abstract: A simple two-step process was developed to render the copper surface with lower friction and long durability. The copper substrate was immersed in a 0.01M NaOH solution to fabricate a textured Cu2O film. A self-assembled monolayer of alkylphosphonic acid was then deposited on the Cu2O film to acquire high hydrophobicity. Scanning electron microscopy, Fourier transform infrared microscopy and water contact angle measurements were used to analyze the morphological features, the chemical composition and hydrophobicity of freshly prepared samples, respectively. Moreover, the friction-reducing behavior of the organic-inorganic composite film sliding against steel was evaluated in a ball-on-plate configuration. It was found that the alkylphosphonic acid films on the textured Cu2O film led to decreased friction with significantly extended life. For a constant load, the increase in chain length of alkylphosphonic acid yields the films that are dramatically more stable against tribological deformation and provide low coefficients of friction over much longer periods of time. [Copyright &y& Elsevier]

The application of field emission (FE) devices requires emitters having a low threshold field (E th , applied field at 10 mA/cm 2 ) and an excellent FE stability at a high emission current density. Herein, we report on the fabrication and field emission characteristics of a carbon nanotube (CNT) emitter formed as a CNT film grown directly on nickel–chromium (Ni80Cr20) alloy wire using microwave plasma enhanced chemical vapour deposition (PECVD). The FE performance of the emitter has a low threshold field of 0.76 V/µm, a large field enhancement factor (8311.3 ± 53.1) and an extremely large emission current density (J max ) of 7.65 A/cm 2 at a relatively low electric field of 2.13 V/µm. The great increase in J max is ascribed to the reinforced adhesion of CNTs to the Ni80Cr20 alloy wire substrates. The direct synthesis of CNTs on the nickel–chromium wire substrate without any catalyst layers and the wrapping of the CNT roots with a carbon nanoflake layer deposited on the surface of the wire substrate are responsible for the enhanced adhesion. The tip-type CNT emitter presents an excellent field emission stability at high emission current densities (3.06 A/cm 2 ), and could potentially be applied to field emission devices. [ABSTRACT FROM AUTHOR]

[Display omitted] • NiS/rGO/Cd 0.3 Zn 0.7 S photocatalysts prepared by facile hydrothermal and photochemical methods. • NiS are uniformly distributed on C 0.3 Z 0.7 S nanorods. • The NiS/rGO/C 0.3 Z 0.7 S exhibits excellent photocatalytic H 2 evolution activity of 1058 μmol h−1. • A possible mechanism was proposed based on the synergistic effect of rGO and NiS. Effectively improving the separation efficiency of photoinduced carriers is of crucial importance for the design of photocatalysts with excellent hydrogen evolution activity. Herein, by combining CdZnS nanorods with rGO and further depositing NiS as cocatalysts, the separation and transfer of photoinduced carriers for CdZnS is significantly improved. Without using any noble metals as cocatalysts, the optimal NiS/0.5%rGO/C 0.3 Z 0.7 S exhibits an outstanding H 2 evolution activity of 1058 μmol h−1 under visible light illumination, which is evidently better than that of pure CdZnS nanorods and most CdZnS-based photocatalysts reported previously. Our study indicates that the introduction of rGO can effectively assist the transfer of photoinduced electrons and evenly distributed NiS on the surface, as the active center for H 2 evolution reaction, can easily capture photoinduced electrons to participate in photocatalytic process. Thus, the synergistic effect of rGO and NiS is considered to be the main cause for the improved photocatalytic performance. This work could offer a facile and low-cost strategy for the construction of composite photocatalysts with high-efficiency hydrogen generation activity. [ABSTRACT FROM AUTHOR]