Morphology-Controlled Synthesis of α-Fe2O3 Nanocrystals Impregnated on g-C3N4-SO3H with Ultrafast Charge Separation for Photoreduction of Cr (VI) Under Visible Light

Sridharan Balu; Yi-Lun Chen; R-C Juang; Thomas C-K Yang; Joon Ching Juan

doi:10.1016/j.envpol.2020.115491

Morphology-Controlled Synthesis of α-Fe₂O₃ Nanocrystals Impregnated on g-C₃N₄-SO₃H with Ultrafast Charge Separation for Photoreduction of Cr (VI) Under Visible Light

Environ Pollut. 2020 Dec:267:115491. doi: 10.1016/j.envpol.2020.115491. Epub 2020 Aug 29.

Authors

Sridharan Balu¹, Yi-Lun Chen¹, R-C Juang², Thomas C-K Yang³, Joon Ching Juan⁴

Affiliations

¹ Department of Chemical Engineering and Biotechnology, National Taipei University of Technology, Taipei, 106, Taiwan, ROC.
² Green Energy and Environmental Laboratories, Industrial Technology Research Institute, Hsinchu, 300, Taiwan, ROC.
³ Department of Chemical Engineering and Biotechnology, National Taipei University of Technology, Taipei, 106, Taiwan, ROC; Precision Analysis and Materials Research Center, National Taipei University of Technology, Taipei, 106, Taiwan, ROC. Electronic address: ckyang@mail.ntut.edu.tw.
⁴ Nanotechnology and Catalysis Research Center (NANOCAT), University of Malaya, Kuala Lumpur, 50603, Malaysia.

PMID: 32911336
DOI: 10.1016/j.envpol.2020.115491

Abstract

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-Fe₂O₃ nanocrystals (α-Fe₂O₃-NCs) were effectively synthesized via a simple solvothermal route. Meanwhile, the sulfonic acid functionalization (SAF) and the impregnation of α-Fe₂O₃-NCs on g-C₃N₄ (α-Fe₂O₃-NCs@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 α-Fe₂O₃-NCs with CN-SAF significantly enhances the optoelectronic properties, ultrafast spatial charge separation, and rapid charge transportation. The α-Fe₂O₃-HPs@CN-SAF and α-Fe₂O₃-NPs@CN-SAF nanocomposites attained 97.41% and 93.64% of Cr (VI) photoreduction in 10 min, respectively. The photocatalytic efficiency of α-Fe₂O₃-NCs@CN-SAF nanocomposite is 2.4 and 2.1 times higher than that of pure g-C₃N₄ and α-Fe₂O₃, respectively. Besides, the XPS, PEC and recycling experiments confirm the excellent photo-induced charge separation via Z-scheme heterostructure and cyclic stability of α-Fe₂O₃-NCs@CN-SAF nanocomposites.

Keywords: Cr (VI) photoreduction; Visible-light; Z-Scheme; g-C(3)N(4)–SO(3)H; α-Fe(2)O(3) NCs.

MeSH terms

Catalysis
Light
Nanocomposites*
Nanoparticles*
Oxidation-Reduction