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The preparation of long-wavelength emitting carbon dots (CDs) with good antibacterial function and biosensing ability through element doping method is the hotspot of present researches. This paper reports the rapid synthesis of nitrogen and phosphorus co-doped long wavelength-emitting CDs (N, P-CDs, λ em = 530 nm) under low reaction temperature (30 min, 60 °C). This method used glucose, polyethyleneimine and phosphoric acid as raw materials, and each raw material worked multi-functionally during the synthesis process. The impacts of raw materials and reaction parameters upon optical properties of prepared N, P-CDs have been studied, and the synthesis mechanism has been discussed. Meanwhile, N, P-CDs were used as antibacterial material with minimum inhibitory concentrations against Staphylococcus aureus and Escherichia coli at 7.5 μg·mL−1 and 0.5 mg·mL−1 respectively. The prepared CDs were also used to realize fluorescence imaging of S. aureus , and work as fluorescence probe to detect Sudan Red I with limit of detection at 43 nM. • Low-temperature and fast synthesis of long-wavelength emitting N, P-CDs • Discussion on the mechanism of synthetic materials affecting the optical properties of CDs • The high inhibitory ability of N, P-CDs against Staphylococcus aureus • The highly sensitive detection of Sudan Red I by N, P-CDs [ABSTRACT FROM AUTHOR]

[Display omitted] • Co 3 S 4 @Co 3 O 4 /N, S-doped carbon core@shell structural composites were constructed. • Interfacial and structural engineering were comprehensively employed. • Interfacial effect optimizes the adsorption properties of the active sites. • Synergistic effect among the composites can modulate the electron configuration. • The optimal catalyst has excellent OER/ORR performances for metal-air batteries. Herein, a class of Co 3 S 4 @Co 3 O 4 /NSC (N, S-doped carbon) composites with core@shell nanostructures were facilely fabricated through a two-step pyrolysis-oxidation strategy using methyl orange and cobalt chloride as raw materials. By constructing heterointerfaces between different components and controlling the surface oxidation degree, the interfacial and synergistic effects endowed the composited catalysts tailorable and excellent bifunctional electrocatalytic activities on oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). A rechargeable Zn-air battery (ZAB) with the optimized catalyst Co 3 S 4 @Co 3 O 4 /NSC-260-8 as air cathode has shown excellent performance with a high specific capacity of 885 mAh·g Zn −1 and energy density of 948 Wh·kg Zn −1 (at 20 mA·cm−2), which is higher than 836 mAh·g Zn −1 and 929 Wh·kg Zn −1 of the one employing Pt/C (20%) + RuO 2 as air cathode under the same conditions. The catalyst also showed robust stability and no obvious decrease in the voltage was observed after 200 h charging and discharging cycles. This work presents a feasible concept to design and construct heterostructural and multifunctional composite catalysts with heterointerfaces. [ABSTRACT FROM AUTHOR]

The rare earth metal Ce-doped cobalt ferrite samples Ce x Co 1− x Fe 2 O 4 ( x = 0.1, 0.3, 0.5) were prepared by the sol–gel autocombustion route. The as-prepared samples were characterized by X-ray diffractometry, scanning electron microscopy, transmission electron microscopy, ICP–atomic emission spectroscopy, and N 2 physisorption. Their catalytic performance was evaluated in oxidation of styrene using hydrogen peroxide (30%) as oxidant. Compared with pristine CoFe 2 O 4 , the Ce-doped samples were found to be more efficient catalysts for the oxidation of styrene to benzaldehyde, with greatly enhanced catalytic performance. Especially, when Ce 0.3 Co 0.7 Fe 2 O 4 was used as catalyst, 90.3% styrene conversion and 91.5% selectivity for benzaldehyde were obtained at 90 °C for 9 h reaction. The catalyst can be magnetically separated easily for reuse, and no obvious loss of activity was observed when it was reused in five consecutive runs. [ABSTRACT FROM AUTHOR]

Abstract: The influence of NiO-doping on the microstructure and dielectric properties of CaCu3Ti4O12–xNiO (x=0, 0.003, 0.006, 0.010, 0.015, and 0.020) ceramics has been investigated using SEM, Raman spectra and dielectric spectrum measurements. The positron annihilation lifetime spectra (PALS) are used to investigate the influence of defects on the dielectric properties. The SEM results show that the grain morphology varies significantly with increasing NiO content. An appropriate small amount of NiO can promote the grain growth, which is beneficial to improve the dielectric properties in a CaCu3Ti4O12 (CCTO) system. Positron results show that there are vacancy-type defects in the experimental samples, and the concentration of the defect and the defect type both change with increasing NiO content. The effects of microstructure including the grain morphology and the vacancy defects on the mechanism of the dielectric properties by adding NiO are discussed. The results demonstrate the importance of the grain morphology and the characteristic of defects in controlling the electrical properties of CCTO ceramics. [Copyright &y& Elsevier]