Single-Pot Solvothermal Synthesis of Single-Crystalline Nickel–Metal Organic Framework Nanosheets for Direct Iron Fuel Cell Applications

Abstract

The usage of iron leads to the generation of large quantities of scrap iron, which is hazardous to health and causes environmental pollution. Recycling techniques are expensive and involve high energy consumption. Instead of recycling, scrap iron can be used as an alternative potential source for fuel cell applications. Here, we report the synthesis of a single-crystalline nickel-based MOF (Ni-MOF), via a single-pot solvothermal technique, as an electrocatalyst to produce hydrogen from scrap iron. Detailed characterization reveals the nanosheet morphology of the Ni-MOF obtained by FESEM; at the same time Ni-MOF formation is confirmed through the XRD spectrum. The as-synthesized Ni-MOF is deposited on nickel foam (NF) and used as an electrocatalyst (Ni-MOF/NF) which exhibits a peak current density of 8.8 A/g (scrap) and response toward hydrogen production at an onset potential of 0.5 V (vs Hg/HgO). The improved performance of the Ni-MOF/NF electrode is ascribed to the high catalytic activity of Ni-MOF owing to the multiple oxidation states of Ni (i.e., Ni2+/3+); the reversible transformation between +2 and +3 oxidation states results in the redox peaks of the catalytic reaction; and the organic ligands in the MOF structure help in improving the conductivity and pore size of the material. The Ni-MOF/NF electrode exhibits outstanding stability with ∼88.1 and ∼72.9% capacity retention after 100,000 and 50,000 s for scrap and iron metal powder, respectively. This proves that the theickel metal–organic framework coated on nickel foam (Ni-MOF/NF) electrocatalyst is an outstanding material for iron source-based fuel cell applications.

Nanoporous Copper–Metal Organic Framework Microneedles on Nickel Foam as a Bifunctional Electrocatalyst for Glycerol Fuel Cell and Electrochemical Glycerol Detection in Biodiesel

“…NF electrodes, with their 3D skeletal structure, strong electrical conductivity, and exceptional electrocatalytic activity, greatly enhance catalyst electrode performance in sensing and fuel cell applications. 16 The as-fabricated, Cu-MOF/NF electrode demonstrated a current density of 690 mA/cm 2 at an onset potential of 0.6 V (vs Hg/HgO), for biodiesel. This bifunctional electrode also showed excellent linear range of detection from 0.01 to 0.9 mM with a sensitivity of 10.7 μA/ mM/cm 2 and excellent selectivity.…”

Synergistic integration of Ni-metal organic framework/SnS2 nanocomposite and nickel foam electrode for ultrasensitive and selective electrochemical detection of albumin in simulated human blood serum

“…The determination of the surface area disclosed a significant value of 35.726 m 2 g −1 , accompanied by a measured pore volume of 0.053 cm 3 g −1 . The recognition of the higher surface area's potential to enhance the activity at the electrode-electrolyte interface plays a crucial role in improving electrochemical performance [24].…”

“…The synthesis of MOF composites can be accomplished using a variety of techniques such as solvothermal [24], mechanochemical [25], hydrothermal [26], sonochemical [27], and microwave-assisted synthesis [28]. Solvothermal method involves the use of solvent at a certain temperature and pressure which will promote the reaction between organic ligands and the metal precursors.…”

“…Solvothermal method involves the use of solvent at a certain temperature and pressure which will promote the reaction between organic ligands and the metal precursors. It offers many advantages including precise control over crystal structure and morphology, enabling the fabrication of materials with tailored properties [24]. It provides high purity, versatility, enhanced reactivity, and scalability, making it a valuable tool for researchers in various fields [23].…”

Shape–Preserved CoFeNi–MOF/NF Exhibiting Superior Performance for Overall Water Splitting across Alkaline and Neutral Conditions

“…Ni-MOF has excellent catalytic activity and electrochemical durability as an electrocatalyst material. However, the overpotential of monomeric MOFs is not satisfactory for rapidly driving OER processes [30,31]. Sun et al synthesized Fe-doped NiCo-MOF (Fe-NiCo-MOF/NF) by solvothermal method.…”