Ag@AgCl nanoparticles grafted on carbon nanofiber: an efficient visible light plasmonic photocatalyst via bandgap reduction.

A novel silver@silver chloride/carbon nanofiber (Ag@AgCl/CNF) hybrid was synthesized by electrospinning, heat treament, and subsequentin situchemical oxidation strategy. The synthesized materials were characterized using x-ray diffraction, Fourier-transform infrared, UV-Vis diffuse reflectance spectroscopy, scanning electron microscopy, and energy dispersive x-ray. The experimental results reveal that the electrospun AgNO3/PAN was carbonized and reduced to Ag/CNF, the Ag/CNF was then partly oxidized to form Ag@AgCl/CNF in which Ag@AgCl nanoparticles (ca. 10-20 nm in diameter) were uniformly bounded to CNFs (ca. 165 nm in diameter). The obtained Ag@AgCl/CNF was employed for Na2S2O8activation under visible light irradiation to treat Rhodamine B (RhB). A remarkable RhB removal of ca. 94.68% was achieved under optimal conditions, and the influence of various parameters on removal efficiency was studied. Quenching experiments revealed that HO•, SO4•-,1O2, and O2•-were major reactive oxygen species, in which O2•-played a pivotal role in RhB degradation. A possible mechanistic route for RhB degradation was proposed.

Characteristics and Morphology of Nanosilica Modified with Isopropyl Tri(dioctyl Phosphate) Titanate Coupling Agent.

In order to improve dispersiveness of nanosilica in polymer matrix, surface organo-modification of nanosilica is necessary. This work reveals silica nanoparticles modified by titanate coupling agent isopropyltri (dioctylphosphate) titanate (KR12) in toluene solvent. Effect of reaction temperature, reaction time and reactant ratio on grafting efficiency have been studied by Thermogravimetric Analysis (TGA). The obtained results exhibit the grafted percentage of titanate coupling agent KR-12 on the surface of nanosilica increased quickly from 4.97 to 13.11 wt.% as increasing the content of KR-12 from 5 to 15 wt.% and raise slower from 13.21 to 13.43 wt.% as content of KR-12 in the range of 30 to 45 wt.%, respectively. The KR-12 content and grafting reaction time affect significantly on the grafting efficiency while temperature of grafting reaction is negative to the grafting efficiency. The results of analysis related to Infrared Spectroscopy and Energy-Dispersive X-ray spectroscopy (EDS) displayed titanate coupling agent KR-12 have been covalently bonded to surface of the nanosilica. The Transmission Electron Microscopy (TEM) images and size distribution indicated that after organic modification, nanosilica particles had average size about 86 nm and the agglomeration of nanoparticles decreased significantly. The obtained results showed that surface treatment of nanosilica with titanate coupling agent KR-12 was successful.