Double Perovskite Cobaltites Integrated in a Monolithic and Noble Metal-Free Photoelectrochemical Device for Efficient Water Splitting

Junjie Zhu; Jónína B Guđmundsdóttir; Ragnar Strandbakke; Kevin G Both; Thomas Aarholt; Patricia A Carvalho; Magnus H Sørby; Ingvild J T Jensen; Matylda N Guzik; Truls Norby; Halvard Haug; Athanasios Chatzitakis

doi:10.1021/acsami.1c01900

Double Perovskite Cobaltites Integrated in a Monolithic and Noble Metal-Free Photoelectrochemical Device for Efficient Water Splitting

ACS Appl Mater Interfaces. 2021 May 5;13(17):20313-20325. doi: 10.1021/acsami.1c01900. Epub 2021 Apr 27.

Affiliations

¹ Institute for Energy Technology (IFE), Instituttveien 18, NO-2007 Kjeller, Norway.
² Centre for Materials Science and Nanotechnology, Department of Chemistry, University of Oslo, FERMiO, Gaustadalléen 21, NO-0349 Oslo, Norway.
³ Department of Physics, University of Oslo, POB 1048 Blindern, NO-0316 Oslo, Norway.
⁴ SINTEF Materials Physics, Forskningsveien 1, NO-0373 Oslo, Norway.
⁵ Department for Neutron Materials Characterization, Institutt for Energiteknikk (IFE), POB 40, NO-2027 Kjeller, Norway.
⁶ Department of Technology Systems, University of Oslo, POB 70, NO-2027 Kjeller, Norway.

Abstract

Water photoelectrolysis has the potential to produce renewable hydrogen fuel, therefore addressing the intermittent nature of sunlight. Herein, a monolithic, photovoltaic (PV)-assisted water electrolysis device of minimal engineering and of low (in the μg range) noble-metal-free catalysts loading is presented for unassisted water splitting in alkaline media. An efficient double perovskite cobaltite catalyst, originally developed for high-temperature proton-conducting ceramic electrolyzers, possesses high activity for the oxygen evolution reaction in alkaline media at room temperatures too. Ba_1-xGd_1-yLa_x+yCo₂O_6-δ (BGLC) is combined with a NiMo cathode, and a solar-to-hydrogen efficiency of 6.6% in 1.0 M NaOH, under 1 sun simulated illumination for 71 h, is demonstrated. This work highlights how readily available earth-abundant materials and established PV methods can achieve high performance and stable and monolithic photoelectrolysis devices with potential for full-scale applications.

Keywords: bias-free water electrolysis; double perovskites; earth abundant elements; oxygen evolution reaction; photoelectrochemical water splitting; solar cells.