Photocatalytic and biocidal activities of ZnTiO2 oxynitride heterojunction with MOF-5 and g-C3N4: A case study for textile wastewater treatment under direct sunlight

Sherif A Younis; Philippe Serp; Hussein N Nassar

doi:10.1016/j.jhazmat.2020.124562

Photocatalytic and biocidal activities of ZnTiO₂ oxynitride heterojunction with MOF-5 and g-C₃N₄: A case study for textile wastewater treatment under direct sunlight

J Hazard Mater. 2021 May 15:410:124562. doi: 10.1016/j.jhazmat.2020.124562. Epub 2020 Nov 18.

Authors

Sherif A Younis¹, Philippe Serp², Hussein N Nassar³

Affiliations

¹ Analysis and Evaluation Department, Egyptian Petroleum Research Institute, Nasr City, Cairo 1172, Egypt; Central Laboratories, Egyptian Petroleum Research Institute, Nasr City, Cairo 11727, Egypt; Nanobiotechnology Program, Faculty of Nanotechnology for Postgraduate Studies, Cairo University, Sheikh Zayed Branch Campus, Sheikh Zayed City, Giza, PO 12588, Egypt. Electronic address: sherifali_r@yahoo.com.
² Laboratoire de Chimie de Coordination UPR CNRS 8241, Composante ENSIACET, Université de Toulouse, UPS-INP-LCC, 4 Allée Emile Monso, BP 44362, 31030 Toulouse Cedex 4, France. Electronic address: philippe.serp@ensiacet.fr.
³ Petroelum Biotechnology Lab., Department of Process Design and Development, Egyptian Petroleum Research Institute (EPRI), Nasr City, Cairo 11727, Egypt; Center of Excellence, October University for Modern Sciences and Arts (MSA), 6th of October City, Giza, PO 12566, Egypt; Nanobiotechnology Program, Faculty of Nanotechnology for Postgraduate Studies, Cairo University, Sheikh Zayed Branch Campus, Sheikh Zayed City, Giza, PO 12588, Egypt.

PMID: 33250306
DOI: 10.1016/j.jhazmat.2020.124562

Abstract

The work aimed to synthesize three heterojunction photocatalysts (E_g = 2.65-2.78 eV) via in-situ encapsulation of 5% zinc doped titanium oxynitride (Zn_0.05TiO_xN_y) catalyst into MOF-5 and bulk (BCN)/sulfur-doped (SCN) g-C₃N₄ supports using a microwave method. The prepared photocatalysts were characterized and utilized to purify textile industrial wastewater from the organic dye (e.g., methylene blue, MB) and microbial (e.g., E. coli, S. aureus, and C. albicans) contaminants under dark, visible, and solar lights. The output data confirmed the higher activity of Zn_0.05TiO_xN_y@SCN and Zn_0.05TiO_xN_y@MOF-5 for photo-induced microbial growth inactivation (> 90%) under visible light, with photo-biocidal efficiency of 0.91-1.69 mCFU/Einstein. Such a phenomenon is ascribed to the synergism between the high antimicrobial capacity of supports and photoactivity of Zn_0.05TiO_xN_y. Also, Zn_0.05TiO_xN_y@SCN exhibited far superiority to mineralize MB dye (K_photo of 2.73 × 10^-2 min^-1) under direct sunlight due to its high photonic (ζ% of 4.4-8.3%)/quantum (QE of 0.56-0.54%) efficiencies for the generation of hydroxyl and superoxide (^-•O₂/•OH) oxidative species. As a practical case study, all heterojunction photocatalysts also demonstrated high-performance stability (5 cycles) for real textile wastewater treatment under sunlight (efficiency = 76.1-84.6%).

Keywords: Biocidal activity; Carbon nitride; Metal-organic framework; Textile wastewater treatment; Zinc-titanium oxynitride.

Publication types

Research Support, Non-U.S. Gov't