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

The use of copper–metal–organic framework (Cu-MOF) as a versatile electrocatalyst signifies a transformative breakthrough with profound implications for sustainable energy and advanced analytical capabilities in the biodiesel industry. We present an economically efficient, Cu-MOF microneedle decorated nickel foam (NF)-based electrochemical sensor for detecting glycerol (Gly) in biodiesel and as an electrocatalyst for glycerol fuel cells. Herein, we utilized a simple and efficient solvothermal approach to synthesize Cu-MOF, then conducted a comprehensive analysis to study the material's morphological, structural, and functional groups using different material characterization techniques like transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transmission infrared spectroscopy (FTIR), etc. The Cu-MOF-modified NF electrocatalyst shows a remarkable current density of 690 mA/cm2, and the sensor exhibits exceptional selectivity, sensitivity, and a low limit of detection (LOD) of 0.172 μM. Cu-MOF/NF is highly selective over other interfering species (methanol, Na+, K+, Ca2+, Mg2+ cations, and phosphates) and in biodiesel samples with an outstanding recovery percentage of ∼101%. The microneedle structure of Cu-MOF plays a pivotal role in augmenting catalytic activity, providing increased surface area and providing active sites for electrochemical reactions. This is the first report on the utilization of Cu-MOF as bifunctional electrocatalysts, exploring their applications in glycerol fuel cells for sustainable energy generation as well as their role in electrochemical sensing for the accurate quantification of glycerol in biodiesel samples.