Atomic orbitals modulated dual functional bimetallic phosphides derived from MOF on MOF structure for boosting high efficient overall water splitting

Abstract

The electronic modulation characteristics of efficient metal phosphide electrocatalysts can be utilized to tune the performance of oxygen evolution reaction (OER). However, improving the overall water splitting performance remains a challenging task. By building metal organic framework (MOF) on MOF heterostructures, an efficient strategy for controlling the electrical structure of MOFs was presented in this study. ZIF-67 was in-situ synthesized on MIL-88 (Fe) using a two-step self-assembly method, followed by low-temperature phosphorization to ultimately synthesize FeP-CoP₃ bimetallic phosphides. By combining atomic orbital theory and theoretical calculations (density functional theory), the results reveal the successful modulation of electronic orbitals in FeP-CoP₃ bimetallic phosphides, which are synthesized from MOF on MOF structure. The synergistic impact of the metal center Co species and the phase conjugation of both kinds of MOFs are responsible for this regulatory phenomenon. Therefore, the catalyst demonstrates excellent properties, demonstrating HER 81 mV (η10) in a 1.0 mol L⁻¹ KOH solution and OER 239 mV (η50) low overpotentials. The FeP-CoP₃ linked dual electrode alkaline batteries, which are bifunctional electrocatalysts, have a good electrocatalytic ability and may last for 50 h. They require just 1.49 V (η50) for total water breakdown. Through this technique, the electrical structure of electrocatalysts may be altered to increase catalytic activity.