Morphology-Controlled Synthesis of α-FeO Nanocrystals Impregnated on g-CN-SOH with Ultrafast Charge Separation for Photoreduction of Cr (VI) Under Visible Light.

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 α-FeO nanocrystals (α-FeO-NCs) were effectively synthesized via a simple solvothermal route. Meanwhile, the sulfonic acid functionalization (SAF) and the impregnation of α-FeO-NCs on g-CN (α-FeO-NCs@CN-SAF) were achieved through complete solvent evaporation technique. The surface functionalization of the sulfonic acid group on g-CN accelerates the faster migration of electrons to the surface owing to robust electronegativity. The incorporation of α-FeO-NCs with CN-SAF significantly enhances the optoelectronic properties, ultrafast spatial charge separation, and rapid charge transportation. The α-FeO-HPs@CN-SAF and α-FeO-NPs@CN-SAF nanocomposites attained 97.41% and 93.64% of Cr (VI) photoreduction in 10 min, respectively. The photocatalytic efficiency of α-FeO-NCs@CN-SAF nanocomposite is 2.4 and 2.1 times higher than that of pure g-CN and α-FeO, respectively. Besides, the XPS, PEC and recycling experiments confirm the excellent photo-induced charge separation via Z-scheme heterostructure and cyclic stability of α-FeO-NCs@CN-SAF nanocomposites.