Heterostructured Ultrathin Two-Dimensional Co-FeOOH Nanosheets@1D Ir-Co(OH)F Nanorods for Efficient Electrocatalytic Water Splitting

Abstract

It is highly desirable to develop high-performance and robust electrocatalysts for overall water splitting, as the existing electrocatalysts exhibit poor catalytic performance toward hydrogen and oxygen evolution reactions (HER and OER) in the same electrolytes, resulting in high cost, low energy conversion efficiency, and complicated operating procedures. Herein, a heterostructured electrocatalyst is realized by growing Co-ZIF-67-derived 2D Co-doped FeOOH on 1D Ir-doped Co(OH)F nanorods, denoted as Co-FeOOH@Ir-Co(OH)F. The Ir-doping couples with the synergy between Co-FeOOH and Ir-Co(OH)F effectively modulate the electronic structures and induce defect-enriched interfaces. This bestows Co-FeOOH@Ir-Co(OH)F with abundant exposed active sites, accelerated reaction kinetics, improved charge transfer abilities, and optimized adsorption energies of reaction intermediates, which ultimately boost the bifunctional catalytic activity. Consequently, Co-FeOOH@Ir-Co(OH)F exhibits low overpotentials of 192/231/251 and 38/83/111 mV at current densities of 10/100/250 mA cm–2 toward the OER and HER in a 1.0 M KOH electrolyte, respectively. When Co-FeOOH@Ir-Co(OH)F is used for overall water splitting, cell voltages of 1.48/1.60/1.67 V are required at current densities of 10/100/250 mA cm–2. Furthermore, it possesses outstanding long-term stability for OER, HER, and overall water splitting. Our study provides a promising way to prepare advanced heterostructured bifunctional electrocatalysts for overall alkaline water splitting.

Deep Reconstruction of the NiFeSP Nanosheet Catalyst for Large Current–Density Water Oxidation

“…Furthermore, the high-resolution TEM image (Figure e) shows that the outer crystalline region and the inner amorphous region form a distinct interface in the nanosheets of post-OER NiFeSP/NF-600. The lattice fringes of the edge of the nanosheets in post-OER NiFeSP/NF-600 about 0.204 and 0.210 nm corresponded to the (210) crystal plane of NiOOH, and the (321) crystal plane of FeOOH, respectively. , This is reinforced further by the SAED pattern given in Figure f. The FeOOH and NiOOH phases are considered to be the active sites responsible for maintaining long-term stability in the OER.…”

A moderate method for in situ growing Fe-based LDHs on Ni foam for catalyzing the oxygen evolution reaction

“…The electrochemical double layer capacitance ( C dl ) based on CV at a scanning rate of 10 to 100 mV s −1 was obtained, and the electrochemical specific surface area (ECSA) was calculated using the following equation: ECSA = C dl / C s , where C s is the specific capacitance, in this work, C s = 0.04 mF cm −2 in 1 M KOH. 35 The stability of the OER was assessed by a chronopotentiometry test (without iR compensation).…”

Fabricating Ru Atom-Doped Novel FeP4/Fe2PO5 Heterogeneous Interface for Overall Water Splitting in Alkaline Environment

“…A heteroatom doping strategy could directly optimize the inner activity and catalytic durability of catalysts because it is conducive to regulate the interaction of different atoms. − For example, Wang et al have utilized the phosphating reaction to achieve self-supporting growth of Ru on FeP 4 nanosheets. The size of the FeP 4 particles and the adsorption strength (Δ G H* ) of proton H* in the HER process were optimized by doping the extremely low content of Ru.…”