Hybrid organic–inorganic H2-evolving photocathodes: understanding the route towards high performance organic photoelectrochemical water splitting. Issue 6 (19th January 2016)

• Record Type: Journal Article
• Authors: Fumagalli, Francesco; Bellani, Sebastiano; Schreier, Marcel; Leonardi, Silvia; Rojas, Hansel Comas; Ghadirzadeh, Alì; Tullii, Gabriele; Savoini, Alberto; Marra, Gianluigi; Meda, Laura; Grätzel, Michael; Lanzani, Guglielmo; Mayer, Matthew T.; Antognazza, Maria Rosa; Di Fonzo, Fabio
• Is Part Of: Journal of materials chemistry. Volume 4:Issue 6(2016)
• Page Start: 2178
• Page End: 2187
• Publication Date: 2016-01-19
• Subjects: Materials -- Research -- Periodicals; Chemistry, Analytic -- Periodicals; Environmental sciences -- Research -- Periodicals; 543.0284
• DOI: 10.1039/c5ta09330a
• Languages: English
• ISSNs: 2050-7488

Abstract

Abstract : The photocathode exhibits 100% Faradaic efficiency and a photocurrent density of 3 mA cm 2 at 0.0 V RHE. Abstract : A promising, yet challenging, route towards renewable production of hydrogen is the direct conversion of solar energy at a simple and low cost semiconductor/water junction. Despite the theoretical simplicity of such a photoelectrochemical device, different limitations among candidate semiconductor materials have hindered its development. After many decades of research on inorganic semiconductors, a conclusive solution still appears out of reach. Here, we report an efficient hybrid organic–inorganic H2 evolving photocathode, consisting of a donor/acceptor blend sandwiched between charge-selective layers and a thin electrocatalyst layer. The role and stability of the different interfaces are investigated, and the conductive polymer is proven to be an efficient material for a semiconductor/liquid PEC junction. The best performing electrodes show high performances with a photocurrent of 3 mA cm −2 at 0 V vs. RHE, optimal process stability with 100% faradaic efficiency during electrode's lifetime, excellent energetics with +0.67 V vs. RHE onset potential, promising operational activity of several hours and by-design compatibility for implementation in a tandem architecture. This work demonstrates organic semiconductors as a radically new option for efficient direct conversion of solar energy into fuels, and points out the route towards high performance organic photoelectrochemical water splitting.