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Nickel nitride decorated nitrogen doped carbon spheres (Ni 3 N/NCS) were synthesized via an eco-friendly one pot nitridation process. The morphology and structure, chemical composition, and electrochemical properties of Ni 3 N/NCS were characterized vie different methods. The Ni 3 N nanoparticles with average diameter of 20 nm were uniformly decorated on the surface of nitrogen doped carbon spheres. The constructed Ni 3 N/NCS sensor exhibited excellent performance for non-enzymatic glucose sensing, which included two wide linear ranges of 1 μM–3000 μM and 3000 μM - 7000 μM with high sensitivity of 2024.18 μAmM−1cm−2 and 1256.98 μAmM−1cm−2. The corresponding detection limits in lower and higher concentration ranges were 0.1 μM and 0.35 μM respectively. The significantly improved electrochemical performance of Ni 3 N/NCS may be due to the rapid charge transfer and high conductivity of Ni 3 N/NCS/GCE, originating from the synergistic effect of Ni 3 N and nitrogen doped carbon spheres. Moreover, the Ni 3 N/NCS sensor also displayed satisfactory recovery results for glucose detection in serum samples. The kinetics of glucose oxidation on the Ni 3 N/NCS electrode were also studied to understand the electrochemical reaction on the surface of the materials. Moreover, the possible mechanisms about the glucose sensing and the formation of Ni 3 N/NCS were also discussed. The present study may provide a rational strategy to eco-friendly prepare highly efficient electrocatalysts for non-enzymatic glucose sensing applications. • The Ni 3 N/NCS was prepared via a facile eco-friendly one pot nitridation process. • Highly improved non-enzymatic glucose sensing performance was obtained on Ni 3 N/NCS. • Enhanced electrochemical activity may be due to the synergistic effect of Ni 3 N and NCS. • The combination of Ni 3 N with NCS accelerated the charge transfer in the electrocatalyst. • The study may provide a rational strategy to design highly efficient sensing materials. [ABSTRACT FROM AUTHOR]

Urchin-like Nb 2 O 5 nanospheres having an overall diameter of 300–500 nm and containing well-ordered independent nanorods with a diameter of 5–10 nm and a length of about 100 nm were synthesized using a facile and template-free method. X-ray diffraction (XRD) and field emission scanning electron microscopy results showed that the morphology of Nb 2 O 5 can be regulated by adjusting the ratio of water/ethanol in the starting solution. High-resolution transmission electron microscopy images indicated that the nanorods grew along the [001] zone direction. Then, the formation mechanism of the urchin-like Nb 2 O 5 was investigated through XRD and transmission electron microscopy. The urchin-like Nb 2 O 5 -1-1 nanospheres obtained at a water/ethanol ratio of 1/1 exhibited the highest photocatalytic activity for the degradation of Rhodamine B (RhB) under visible light, showing about 4.4 times of the activity of Nb 2 O 5 -1-4 and about 4.1 times of that of TiO 2 (P25). The degradation mechanism of RhB on the urchin-like Nb 2 O 5 nanospheres was demonstrated by terephthalic acid photoluminescence technique and photoelectrochemical measurements. The results revealed that the dye-sensitized photodegradation process was the main mechanism of RhB degradation under visible light irradiation. [ABSTRACT FROM AUTHOR]

• Co-free anti-bacterial Cr-Fe-Ni-Cu-Si HEAs were designed. • These HEAs have high mechanical properties and good corrosion resistance. • Increasing Si would lead to the enhancement in strength but decrease in plasticity. [Display omitted] In this work, a series of Co-free CrFeNiCuSi x (x = 0.2, 0.3) high entropy alloys (HEAs) were designed and fabricated by suction casting, and their microstructure, mechanical properties, corrosion resistance and anti-bacterial behaviors have been systematically investigated. It is found that, all these HEAs are composed of FCC phase and have dendrite structure, while the dendrite and inter-dendrite regions are Cu-deplete and Cu-rich, respectively. Moreover, the increase in Si leads to the strengthening of this series of HEAs but would reduce their plasticity. The corrosion resistance is closely correlated with the distribution of Cu in these HEAs. The anti-bacterial rate against E. coli. is ~97% when x = 0.2, while that is ~90% when x = 0.3, indicating high anti-bacterial properties of these HEAs. This work indicates that these designed Co-free HEAs could have excellent comprehensive properties combining high ultimate tensile strength and plasticity, as well as good corrosion resistance and anti-bacterial properties, which provides a novel route in designing high-performance and low-cost anti-bacterial HEAs. [ABSTRACT FROM AUTHOR]

Abstract The Ni 3 (PO 4) 2 /CSs composite microspheres were synthesized via a simple two step hydrothermal process. The composition and morphology of the microspheres were characterized by SEM, TEM, EDS, XRD and XPS. The Ni 3 (PO 4) 2 nanoparticles with diameter less than 10 nm have been uniformly decorated on the carbon spheres. The formation mechanism of the Ni 3 (PO 4) 2 /CSs and their corresponding glucose sensing process have also been proposed. The as prepared Ni 3 (PO 4) 2 /CSs showed greatly enhanced performance for glucose sensing than that of Ni 3 (PO 4) 2 , which may be due to the synergistic effect of Ni 3 (PO 4) 2 nanoparticles and carbon spheres resulting in a high efficiency of charge transfer. The Ni 3 (PO 4) 2 /CSs modified electrodes exhibited excellent glucose sensing performance, with wide linear range of (5 μM–2.5 mM) and (2.5 mM–7.5 mM), and corresponding sensitivity of 480.153 μAmM−1cm−2 and 219.898 μAmM−1cm−2. The detection limit of the Ni 3 (PO 4) 2 /Cs/GCE is found to be 1.67 μM (S/N = 3). Moreover, satisfactory results were also obtained using the as prepared sensor to analyze glucose concentration in serum samples. These results showed that Ni 3 (PO 4) 2 /CSs can be a favorable electrochemical sensing material for constructing the non-enzymatic sensors. Highlights • Ni 3 (PO 4) 2 nanoparticles were uniformly decorated on the carbon sphere surface. • Ni 3 (PO 4) 2 /CSs composite microsphere showed highly improved glucose sensing performance. • The sensors also displayed satisfactory results in real serum samples analysis. • High charge transfer efficiency was obtained by combination of Ni 3 (PO 4) 2 and carbon spheres. • Enhanced performance is due to the synergistic effect of Ni 3 (PO 4) 2 and carbon spheres. [ABSTRACT FROM AUTHOR]

• Novel ferromagnetic Fe 40 Co 40 Ni 10 M 10 (M = Al, Mn) MEAs were designed. • Al is beneficial for fully BCC structure formation via casting. • Mn leads to dual-phase formation, grain refinement and high mechanical properties. • Heat treatment could increase B s and mechanical properties of these MEAs. The influences of Al and Mn on microstructure, magnetic and mechanical properties of Fe 40 Co 40 Ni 10 M 10 (M = Al and Mn) medium entropy alloys (MEAs) have been systematically investigated. It is found that the Fe 40 Co 40 Ni 10 Al 10 has body-centered cubic (BCC) structure and Fe 40 Co 40 Ni 10 Mn 10 has a mixture of face-centered cubic (FCC) and BCC structures in as-cast state, while the former one changes to FCC + BCC dual-phase structure after heat treatment at 1073 K for 1 h. Fe 40 Co 40 Ni 10 Al 10 displays higher saturated magnetization (B s) as compared to Fe 40 Co 40 Ni 10 Mn 10 in as-cast state, while heat treatment significantly enhances B s of Fe 40 Co 40 Ni 10 Mn 10. Besides, it is intriguing that Fe 40 Co 40 Ni 10 Mn 10 shows higher yield strength and plasticity compared to Fe 40 Co 40 Ni 10 Al 10 , while heat treatment could enhance comprehensive mechanical properties of this series of MEAs. In addition, the B s of heat-treated Fe 40 Co 40 Ni 10 Mn 10 is 187.9 emu/g, which is among the highest in the reported ferromagnetic HEAs/MEAs. The correlation among the composition, phase evolution, magnetic properties, and mechanical properties in these MEAs is discussed in detail. This work provides a novel route for developing high-performance ferromagnetic HEAs/MEAs. [ABSTRACT FROM AUTHOR]