Solar Hydrogen Fuel Generation from Wastewater—Beyond Photoelectrochemical Water Splitting: A Perspective

Sudhagar Pitchaimuthu (), Kishore Sridharan, Sanjay Nagarajan, Sengeni Ananthraj, Peter Robertson, Moritz F. Kuehnel, Ángel Irabien and Mercedes Maroto-Valer
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Sudhagar Pitchaimuthu: Research Centre for Carbon Solutions, Institute of Mechanical and Processing Engineering, School of Engineering & Physical Science, Heriot-Watt University, Edinburgh EH14 4AS, UK
Kishore Sridharan: Department of Nanoscience and Technology, School of Physical Sciences, University of Calicut, Thenhipalam 673635, India
Sanjay Nagarajan: Department of Chemical Engineering, University of Bath, Bath BA2 7AY, UK
Sengeni Ananthraj: Department of Applied Chemistry, School of Advanced Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku-ku, Tokyo 169-8555, Japan
Peter Robertson: School of Chemistry and Chemical Engineering, Queen’s University, Belfast BT7 1NN, UK
Moritz F. Kuehnel: Department of Chemistry, Swansea University, Singleton Park, Swansea SA2 8PP, UK
Ángel Irabien: Department of Chemical and Biomolecular Engineering (ETSIIT), University of Cantabria, Avda. los Castros, 39005 Santander, Spain
Mercedes Maroto-Valer: Research Centre for Carbon Solutions, Institute of Mechanical and Processing Engineering, School of Engineering & Physical Science, Heriot-Watt University, Edinburgh EH14 4AS, UK

Energies, 2022, vol. 15, issue 19, 1-23

Abstract: Green hydrogen—a carbon-free renewable fuel—has the capability to decarbonise a variety of sectors. The generation of green hydrogen is currently restricted to water electrolysers. The use of freshwater resources and critical raw materials, however, limits their use. Alternative water splitting methods for green hydrogen generation via photocatalysis and photoelectrocatalysis (PEC) have been explored in the past few decades; however, their commercial potential still remains unexploited due to the high hydrogen generation costs. Novel PEC-based simultaneous generation of green hydrogen and wastewater treatment/high-value product production is therefore seen as an alternative to conventional water splitting. Interestingly, the organic/inorganic pollutants in wastewater and biomass favourably act as electron donors and facilitate the dual-functional process of recovering green hydrogen while oxidising the organic matter. The generation of green hydrogen through the dual-functional PEC process opens up opportunities for a “circular economy”. It further enables the end-of-life commodities to be reused, recycled and resourced for a better life-cycle design while being economically viable for commercialisation. This review brings together and critically analyses the recent trends towards simultaneous wastewater treatment/biomass reforming while generating hydrogen gas by employing the PEC technology. We have briefly discussed the technical challenges associated with the tandem PEC process, new avenues, techno-economic feasibility and future directions towards achieving net neutrality.

Keywords: photoelectrocatalysis; dual-functional photocatalysis; hydrogen generation; wastewater treatment; biomass reforming (search for similar items in EconPapers)
JEL-codes: Q Q0 Q4 Q40 Q41 Q42 Q43 Q47 Q48 Q49 (search for similar items in EconPapers)
Date: 2022
References: View references in EconPapers View complete reference list from CitEc
Citations: View citations in EconPapers (4)

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