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

Novel fibrous [email protected] @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 sol-gel 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 [email protected] composites. SEM observations showed that the [email protected] 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 [email protected] composites presented the characteristic diffraction peaks at 26° and 32° assigned to apatite components. FT-IR spectra revealed that [email protected] composites contained both Si O Si bonds and P O P groups. After immersion in the suspension of Au nanoparticles , the [email protected] composites supported the in situ immobilization of Au nanoparticles to produce [email protected] @Au composites. When incubated in the aqueous mixture of 4-nitrophenol and NaHB 4 , the fibrous [email protected] @Au composites presented a superior photo-catalytic activity and rapidly catalyzed the reduction of 4-nitrophenol to 4-aminophenol.