Understanding Structure-Activity Relationship in Pt-loaded g-C3 N4 for Efficient Solar- Photoreforming of Polyethylene Terephthalate Plastic and Hydrogen Production

Thi Kim Anh Nguyen; Thành Trần-Phú; Xuan Minh Chau Ta; Thien N Truong; Josh Leverett; Rahman Daiyan; Rose Amal; Antonio Tricoli

doi:10.1002/smtd.202300427

Understanding Structure-Activity Relationship in Pt-loaded g-C₃ N₄ for Efficient Solar- Photoreforming of Polyethylene Terephthalate Plastic and Hydrogen Production

Small Methods. 2024 Feb;8(2):e2300427. doi: 10.1002/smtd.202300427. Epub 2023 Sep 15.

Authors

Thi Kim Anh Nguyen^{1

2}, Thành Trần-Phú^{1

2}, Xuan Minh Chau Ta^{1

2}, Thien N Truong³, Josh Leverett⁴, Rahman Daiyan⁴, Rose Amal⁴, Antonio Tricoli^{1

2}

Affiliations

¹ Nanotechnology Research Laboratory, College of Science, Research School of Chemistry, The Australian National University, Canberra, ACT, 2601, Australia.
² Nanotechnology Research Laboratory, Faculty of Engineering, University of Sydney, Sydney, NSW, 2006, Australia.
³ School of Engineering, The Australian National University, Canberra, ACT, 2601, Australia.
⁴ Particles and Catalysis Research Laboratory, School of Chemical Engineering, The University of New South Wales, Sydney, NSW, 2052, Australia.

PMID: 37712209
DOI: 10.1002/smtd.202300427

Abstract

Coupling the hydrogen evolution reaction with plastic waste photoreforming provides a synergistic path for simultaneous production of green hydrogen and recycling of post-consumer products, two major enablers for establishment of a circular economy. Graphitic carbon nitride (g-C₃ N₄ ) is a promising photocatalyst due to its suitable optoelectronic and physicochemical properties, and inexpensive fabrication. Herein, a mechanistic investigation of the structure-activity relationship of g-C₃ N₄ for poly(ethylene terephthalate) (PET) photoreforming is reported by carefully controlling its fabrication from a subset of earth-abundant precursors, such as dicyandiamide, melamine, urea, and thiourea. These findings reveal that melamine-derived g-C₃ N₄ with 3 wt.% Pt has significantly higher performance than alternative derivations, achieving a maximum hydrogen evolution rate of 7.33 mmol_H2 g_cat ^-1 h^-1 , and simultaneously photoconverting PET into valuable organic products including formate, glyoxal, and acetate, with excellent stability for over 30 h of continuous production. This is attributed to the higher crystallinity and associated chemical resistance of melamine-derived g-C₃ N₄ , playing a major role in stabilization of its morphology and surface properties. These new insights on the role of precursors and structural properties in dictating the photoactivity of g-C₃ N₄ set the foundation for the further development of photocatalytic processes for combined green hydrogen production and plastic waste reforming.

Keywords: PET; carbon nitride; photoreforming; plastic waste; solar to hydrogen.

Abstract

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