Synthesis and characterization of electrospun polyacrylonitrile/graphene nanofibers embedded with SrTiO3/NiO nanoparticles for water splitting

Abstract

For over two decades, various photocatalysts have been investigated and tested under infrared, visible and UV light sources. This study reports the synthesis of nickel oxide-loaded strontium titanate (NiO-SrTiO3) particles on electrospun polyacrylonitrile (PAN) nanofibers embedded with graphene nanoplatelets for improved water splitting. In this study, graphene nanoplatelets were first dispersed in dimethylformamide (DMF), sonicated for 30 minutes, and then polyacrylonitrile (PAN) powder was added to the previous solution to make PAN polymeric dispersions prior to the electrospinning process. After oxidizing at 270 degrees C for 2 hrs, the electrospun PAN nanofibers were immersed in a solution containing ethanol, titanium(IV)-isopropoxide [C12H28O4Ti] and strontium nitrate [Sr(NO3)(2)]. This solution was then amended with NiO nanoparticles dispersed in toluene. The surface treated PAN fibers were annealed at 600 degrees C in air for 1 hr to transform them into a crystalline form for better photocatalyst efficiency. Ultraviolet (UV) spectrophotometry, Fourier transform infrared radiation (FTIR), and differential scanning calorimetry (DSC) techniques were used to characterize the structural properties of the graphene/PAN carbon fibers incorporated with NiO-SrTiO3. The morphology and dimensions of the nanofibers were observed by scanning electron microscopy (SEM). The structures of the calcined nanofibers were determined by Raman spectroscopy and X-ray diffraction (XRD).