Strong Electronic Interaction Enhanced Electrocatalysis of Metal Sulfide Clusters Embedded Metal–Organic Framework Ultrathin Nanosheets toward Highly Efficient Overall Water Splitting

Abstract

Unique metal sulfide (MS) clusters embedded ultrathin nanosheets of Fe/Ni metal-organic framework (MOF) are grown on nickel foam (NiFe-MS/MOF@NF) as a highly efficient bifunctional electrocatalyst for overall water splitting. It exhibits remarkable catalytic activity and stability toward both the oxygen evolution reaction (OER, ƞ = 230 mV at 50 mA cm −2) and hydrogen evolution reaction (HER, ƞ = 156 mV at 50 mA cm −2) in alkaline media, and bi-functionally catalyzes overall alkaline water splitting at a current density of 50 mA cm −2 by 1.74 V cell voltage without iR compensation. The enhancement mechanism is ascribed to the impregnated metal sulfide clusters in the nanosheets, which not only promote the formation of ultrathin nanosheet to greatly enlarge the reaction surface area while offering high electric conductivity, but more importantly, efficiently modulate the electronic structure of the catalytically active atom sites to an electron-rich state via strong electronic interaction and strengthen the adsorption of oxygenate intermediate to facilitate fast electrochemical reactions. This work reports a highly efficient HER/OER bifunctional electrocatalyst and may shed light on the rational design and synthesis of uniquely structured MOF-derived catalysts.

Synthesis of Cu2O Nanostructures with Tunable Crystal Facets for Electrochemical CO2 Reduction to Alcohols

“…In addition, the fitted plots of bulk Cu and CuO are also provided in Figure S7. 44 The results in Table S1 The stability of the Cu 2 O catalysts in ECR is an important factor that needed to be considered in practical application. In addition, the total FEs of the liquid alcohols are 70.2 and 17.0% for bulk Cu and CuO, respectively.…”

Developments and Perspectives on Robust Nano‐ and Microstructured Binder‐Free Electrodes for Bifunctional Water Electrolysis and Beyond

“…As shown in Figure 32i, ultrathin nanosheets of Fe/ Ni metal-organic framework (MOF) grown on NF (NiFe-MS/ MOF@NF) performed as a highly efficient bifunctional electrocatalyst. [360] It showed significant catalytic activity and stability toward both OER (≈230 mV at 50 mA cm −2 ) and HER (156 mV at 50 mA cm −2 ) in an alkaline electrolyte and bi-functionally catalyzes overall alkaline water splitting at a current density of 50 mA cm −2 by a cell voltage of 1.74 V. The mechanism for improvement is attributed to the impregnated metal sulfide clusters in the nanosheets, which stimulates the formation of ultrathin nanosheets to significantly increase the surface area and leads to a high electric conductivity, and enlarges the catalytic reaction area to provide more exposed active sites for the catalytic reaction. Iron-doped nickel MOF nanosheets in situ grown on conductive NF (Fe-Ni MOF NSs/NF) provided a highly exposed surface area and abundant metal sites, which are beneficial to electrocatalytic OER performance.…”

Binder free construction of hollow hierarchical Mn–Co–P nanoarrays on nickel foam as an efficient bifunctional electrocatalyst for overall water splitting

“…The electrochemical water splitting process involves two main half-reactions: the hydrogen evolution reaction (HER) at the cathode and oxygen evolution reaction (OER) at the anode. 6–9 Noble metal-based catalysts, such as Pt and IrO 2 , show high activity for the HER and OER, respectively, and are currently the best catalyst materials in the field of hydrogen production by electrolysis of water. 10,11 However, high costs and rare distribution make their further large-scale commercial applications impossible.…”