Morphology-Controlled Synthesis of α-Fe_2O_3 Nanocrystals Impregnated on g-C_3N_4-SO_3H with Ultrafast Charge Separation for Photoreduction of Cr (Ⅵ) Under Visible Light

摘要

Surface functionalization and shape modifications are the key strategies being utilized to overcome the limitations of semiconductors in advanced oxidation processes (AOP). Herein, the uniform alpha-Fe2O3 nanocrystals (alpha-Fe2O3-NCs) were effectively synthesized via a simple solvothermal route. Meanwhile, the sulfonic acid functionalization (SAF) and the impregnation of alpha-Fe2O3-NCs on g-C3N4 (alpha-Fe2O3 eNCs@CN-SAF) were achieved through complete solvent evaporation technique. The surface functionalization of the sulfonic acid group on g-C3N4 accelerates the faster migration of electrons to the surface owing to robust electronegativity. The incorporation of alpha-Fe2O3-NCs with CN-SAF significantly enhances the optoelectronic properties, ultrafast spatial charge separation, and rapid charge transportation. The alpha-Fe2O3-HPs@CN-SAF and alpha-Fe2O3-NPs@CN-SAF nanocomposites attained 97.41% and 93.64% of Cr (VI) photoreduction in 10 min, respectively. The photocatalytic efficiency of alpha-Fe2O3-NCs@CN-SAF nanocomposite is 2.4 and 2.1 times higher than that of pure g-C3N4 and alpha-Fe2O3, respectively. Besides, the XPS, PEC and recycling experiments confirm the excellent photo-induced charge separation via Z-scheme heterostructure and cyclic stability of alpha-Fe2O3-NCs@CN-SAF nanocomposites. (c) 2020 Elsevier Ltd. All rights reserved.