The route for commercial photoelectrochemical water splitting: a review of large-area devices and key upscaling challenges

• Type: Another Publication in an International Scientific Journal
• Date: 2024-01-30

Authors

Dias, P. (Author) FEUP; Lopes, T. (Author) FEUP; Adélio Mendes (Author) FEUP; António Vilanova (Author) Other

Journal

The Journal is awaiting validation by the Administrative Services.

Title: CHEMICAL SOCIETY REVIEWS

Vol. 53

Pages: 2388-2434

ISSN: 0306-0012

Publisher: ROYAL SOC CHEMISTRY

Indexing

ISI Web of Knowledge - 95 Citations

Scopus - 101 Citations

Other information

Authenticus ID: P-00Z-XRB

DOI: 10.1039/d1cs01069g

Abstract (EN): Green-hydrogen is considered a key player in the energy market for the upcoming decades. Among currently available hydrogen (H2) production processes, photoelectrochemical (PEC) water splitting has one of the lowest environmental impacts. However, it still presents prohibitively high production costs compared to more mature technologies, such as steam methane reforming. Therefore, the competitiveness of PEC water splitting must rely on its environmental and functional advantages, which are strongly linked to the reactor design, to the intrinsic properties of its components, and to their successful upscaling. This review gives special attention to the engineering aspects and categorizes PEC devices into four main types, according to the configuration of electrodes and strategies for gas separation: wired back-to-back, wireless back-to-back, wired side-by-side, and wired separated electrode membrane-free. Independently of the device architecture, the use of concentrated sunlight was found to be mandatory for achieving competitive green-H2 production. Additionally, feasible strategies for upscaling the key components of PEC devices, especially photoelectrodes, are urgently needed. In a pragmatic context, the way to move forward is to accept that PEC devices will operate close to their thermodynamic limits at large-scale, which requires a solid convergence between academics and industry. Research efforts must be redirected to: (i) build and demonstrate modular devices with a low-cost and highly recyclable embodiment; (ii) optimize thermal and power management; (iii) reduce ohmic losses; (iv) enhance the chemical stability towards a thousand hours; (v) couple solar concentrators with PEC devices; (vi) boost PEC-H2 production through the use of organic compounds; and (vii) reach consensual standardized methods for evaluating PEC devices, at both environmental and techno-economic levels. If these targets are not met in the next few years, the feasibility of PEC-H2 production and its acceptance by industry and by the general public will be seriously compromised. The demand for green-H2 is steadily growing and PEC water splitting, one of the cleanest production routes, shall experience unparalleled economic and research stimulus, as the transition from lab-scale to commercial PEC devices is urgently needed.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 47