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Exploring novel materials for efficient carbon dioxide (CO2) capture and separation is highly desired in environmental and industrial area, which has gain much attention. Herein, by means of density functional theory investigation including dispersion, we show strong and selective CO2 uptake on fluorine-doped porous BN (p-BN) via examining the adsorption properties, electronic structure, work function and charge population of pristine p-BN and F-doped p-BN. Our results indicate that the work function can be significantly reduced by the F atoms-induced impurity states in the band gap of p-BN. Then, we highlight that p-BN with FN defect presents highly desirable adsorption ability of CO2 with an adsorption energy of 4.35 eV, which have been illuminated to be originated from the robust chemical reaction accompanying with charge transfer of −0.491 e. Meanwhile, p-BN with FN exhibit excellent adsorption selectivity to CO2 with a series of adsorptive substances (CO2, N2, H2, CH4, H2S), which suggests promising application potential in CO2 separation. Finally, the stability of F doped p-BN have confirmed by the vibration frequencies and formation energy analyses. Our finding will open a new way to facilitate application of p-BN in CO2 capture and separation.

Ligand protected noble metal nanoclusters have unique physical and chemical properties and the effects of metal nanoclusters on photoluminescence and energy transfer process for fluorescence molecules are still unclear. In this work, we prepared silver nanoclusters (Ag NCs) with different emission wavelengths (blue, green and red emission) and investigated the energy transfer process between Ag NCs and fluorescein isothiocyanate (FITC). The photoluminescence of FITC can be regulated by the Ag NCs due to various electrons transfer and energy transfer processes between Ag NCs and FITC. The FITC can serve as electrons donor or acceptor which determines the electrons transfer direction between FITC and Ag NCs with different emissions. Astonishingly, the photobleaching of FITC can be effectively inhibited after interacting with Ag NCs, which will surely be of profound significance to the application of FITC.

Conversion coatings on Ti-6Al-4V alloy was prepared through chemical modification in phytic acid and ammonium fluoride mixed solution. The influences of pH, time and the composition of solution on the microstructure of alloy surface were investigated. Scanning electron microscopy was used to observe the microstructure. The chemical composition of alloy surface before and after modification was investigated by energy dispersive X-ray spectroscopy. The results indicated that a conversion coating could be formed on the Ti-6Al-4V alloy in a mixed solution of phytic acid and ammonium fluoride, the growth and microstructure of the conversion coatings were critically dependent on the pH, time and concentration of phytic acid and ammonium fluoride. In 100 mg/ml phytic acid containing 125 mg/ml ammonium fluoride solution with a pH of 6, a compact conversion coating with the thickness of about 4.7 μm formed after 30 min immersion on Ti-6Al-4V alloy surface. The preliminary evaluation of bioactivity of conversion coating was performed by in vitro cell experiments. The results showed that this chemical modification method is a promising surface modification technique for Ti-6Al-4V alloy inplants.

We disclose the effects of localized surface plasmon resonance (LSPR) of Ag nanoparticles (NPs) on luminescence properties of carbon dots (CDs) with blue, green and yellow emission, respectively. The Ag NPs without coating layer result in fluorescence quenching of CDs with blue, green and yellow emissions. The Ag NPs coated with SiO2 layer only quench the blue emitting CDs (B-CDs) since the overlap of emission and LSPR absorption of Ag NPs. However, the fluorescence enhancement of CDs with green (G-CDs) and yellow emission (Y-CDs) can be realized by adjusting the size of the Ag NPs and the distance between Ag NPs and CDs via silica coating (Ag@SiO2). The luminescence intensity of G-CDs and Y-CDs can be improved 5–6 times as the coating thickness of SiO2 is 15 nm. Fluorescence quenching and enhancement mechanism can be clarified by the electron transition and energy transfer process between CDs and Ag NPs, which provides guidance principle for LSPR enhanced fluorescence.