Synergistic Effect of Strontium Ions and Graphite as Dual Cocatalysts for Enhancing Photocatalytic Activity of Small Area Titania Film Stacked by One-Dimensional Nanofibers

Abstract

Focusing on the degradation of organic dyes in wastewater, a novel titania composite nanofiber small area film photocatalyst with improvedphotocatalytic activity using strontium ions and graphite as dual cocatalysts has been synthesized by electrospinning and hydrothermal methods.Morphology control, doping causing crystal defect engineering (strontium ion doping), and heterojunction building (graphite surface modification) strategies are simultaneously applied to the synthetic design of new photocatalysts.In degradation tests of rhodamine B, methyl orange, methylene blue, and malachite green, the degradation rate constants were 2.57, 2.85, 3.06, or 3.54 times higher than those of pure titania, respectively.The composite nanofiber small area film exhibited excellent recyclability in fourrecycling tests.The improved photocatalytic activity of titania composite nanofiber small area film is attributed to the morphology of the nanofibers with the addition of more reaction sites, dopingwith more crystal defects, and heterojunctions providing channels for the transfer of photogenerated carriers.Design solutions with the synergistic effects of multiple strategies inform the use of titania in industrial applications.