Scalable Photocatalyst Panels for Photoreforming of Plastic, Biomass and Mixed Waste in Flow

• Published in: ChemSusChem Vol. 14; no. 19; pp. 4190 - 4197
• Main Authors: Uekert, Taylor, Bajada, Mark A., Schubert, Teresa, Pichler, Christian M., Reisner, Erwin
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 05.10.2021
• Subjects: Ambient temperature; Biomass; Carbon nitride; Electromagnetic absorption; Hydrogen production; immobilisation; Mixed waste; Nuclear fuels; Organic chemistry; Panels; Phosphides; photocatalysis; Photocatalysts; photoreforming; Recyclability; Reforming; scaling; Seawater; Slurries; Sunlight; waste; Waste management
• ISSN: 1864-5631; 1864-564X
• DOI: 10.1002/cssc.202002580

Solar‐driven reforming uses sunlight and a photocatalyst to generate H2 fuel from waste at ambient temperature and pressure. However, it faces practical scaling challenges such as photocatalyst dispersion and recyclability, competing light absorption by the waste solution, slow reaction rates and low conversion yields. Here, the immobilisation of a noble‐metal‐free carbon nitride/nickel phosphide (CNx|Ni2P) photocatalyst on textured glass is shown to overcome several of these limitations. The 1 cm2 CNx|Ni2P panels photoreform plastic, biomass, food and mixed waste into H2 and organic molecules with rates comparable to those of photocatalyst slurries. Furthermore, the panels enable facile photocatalyst recycling and novel photoreactor configurations that prevent parasitic light absorption, thereby promoting H2 production from turbid waste solutions. Scalability is further verified by preparing 25 cm2 CNx|Ni2P panels for use in a custom‐designed flow reactor to generate up to 21 μmolH2  m−2 h−1 under “real‐world” (seawater, low sunlight) conditions. The application of inexpensive and readily scalable CNx|Ni2P panels to photoreforming of a variety of real waste streams provides a crucial step towards the practical deployment of this technology. Waste to fuel: Carbon nitride/nickel phosphide photocatalyst panels are prepared by a simple drop‐casting procedure and used to produce hydrogen fuel from a variety of plastic, biomass, food and mixed waste in an up‐scaled flow reactor.