High-valence-state Ni–Fe bimetallic phosphonate nanoribbons catalyst for enhanced photocatalytic and electrocatalytic oxygen production

Abstract

The design and synthesis of economy and efficiency materials for oxygen evolution reaction (OER) have been a continuous hot spot in the field of scientific study. Herein, a high-valence-state two-dimension (2D) NiFe phosphonate-based (NiFeP) nanoribbons catalyst has been constructed through a one-step solvothermal process. The NiFeP nanoribbons exhibit highly active in both photocatalytic and electrocatalytic water oxidation due to the 2D nanoribbons and high-valence Ni3+ sites. The 2D nanoribbons not only provide more reactive sites for OER but also shorten bulk diffusion distance with better photoexcited carrier transport from the interior to the surface. Meanwhile, the existence of high-valence Ni3+ could be acted as an efficient redox site to reduce the overpotential and facilitate the catalytic reaction. In consequence, the NiFeP nanoribbons catalyst demonstrates a superior O2 yield of 65.7% and O2 production rate of 25.97 umol s−1 g−1, which are comparable or even much higher than those other reported transition metal oxide photocatalysts. At last, the possible proton-coupled electron transfer mechanism is also proposed. This study not only demonstrates the potential of a low-cost metal phosphonate OER catalyst but also provides a referential system for the fabrication of high activity and stability catalysts toward replacing noble metals for energy storage and conversion. High-valence-state 2D NiFe phosphonate-based nanoribbons catalyst has been constructed for the first time through a one-step solvothermal process without any organic additives or template agent. The as-prepared catalyst of NiFeP nanoribbons exhibits highly active in both photocatalytic and electrocatalytic water oxidation.