Facile synthesis of novel fibrous silica@apatite@Au composites with superior photo-catalytic activity

摘要

Novel fibrous silica@apatite@Au composites with superior photo-catalytic activity were facilely synthesized through combination of electrospinning technique, bio-mineralization, and in situ immobilization. Silica nanofibers with the diameter of 486 +/- 60 nm were synthesized through electrospinning of the solgel mixture of gelatin, tetraethoxysilane, acetic acid, water, and calcium chloride followed by sintering process. After bio-mineralization in the Kokubo's simulated body fluid, silica nanofibers supported in situ deposition of fibrous apatite nanosheet flowers to produce fibrous silica@apatite composites. SEM observations showed that the silica@apatite composites had the fibrous feature with the diameter of 2498 +/- 608 nm and their surface was very rough and constructed by numerous apatite nanosheets with the thickness around 10 nm. XRD patterns showed that the fibrous silica@apatite composites presented the characteristic diffraction peaks at 26 degrees and 32 degrees assigned to apatite components. FT-IR spectra revealed that silica@apatite composites contained both Si-O-Si bonds and P-O-P groups. After immersion in the suspension of Au nanoparticles, the silica@apatite composites supported the in situ immobilization of Au nanoparticles to produce silica@apatite@Au composites. When incubated in the aqueous mixture of 4-nitrophenol and NaHB4, the fibrous silica@apatite@Au composites presented a superior photo-catalytic activity and rapidly catalyzed the reduction of 4-nitrophenol to 4-aminophenol. (C) 2018 Elsevier Ltd. All rights reserved.