High-valence-state nickel-iron phosphonates with urchin-like hierarchical architecture for highly efficient oxygen evolution reaction

Abstract

The exploitation of highly efficient, low-cost, and durable catalysts for photocatalytic water oxidation is highly desirable in the field of sustainable energy conversion and storage. Here, we demonstrate the preparation of urchin-like 3D nickel-iron phenyl phosphonates (NiFeP) hierarchical architecture fabricated by ultrathin nanosheets for photocatalytic water oxidation with high efficiency. The urchin-like NiFeP hierarchical architecture is prepared by a facile solvothermal synthesis without any organic additives. The urchin-like 3D hierarchical architecture exhibits a large specific surface area and abundant mesopores distribution, which affording more active catalytic sites and multi-electron transport channel. In the presence of high-valence Ni3+ sites could act as the main redox site to decrease the overpotential of water oxidation reaction. In consequence, using [Ru(bpy)3]Cl2 photosensitizer under visible light irradiation, the urchin-like NiFeP photocatalyst demonstrates a high oxygen evolution activity, giving a superior O2 yield of 76% and O2 production rate of 23.66 umol s−1 g−1. Moreover, the urchin-like NiFeP photocatalyst is highly stable for reuse. This work extends the development of transition metal phosphonates and provides a platform for designing high performance, economic and stable catalysts.