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Boosting sustainable hydrogen production via water splitting and urea oxidation using spinel hollow-sphere nano catalysts
Author(s)
Lin, Hsin Yu
Vasu, Dhanapal
Tsang, Chun Han
Hsu, Cheng Shan
Prashanth, Gopi
Chiu, Te Wei
Date Issued
October 1, 2025
Type
Article
Abstract
In this study, spinel MgCo2O4 materials were synthesized using three different techniques: freeze-drying, solid-state, and hydrothermal methods, to evaluate their structural, morphological, and electrocatalytic properties. Comprehensive characterization techniques including XRD, Raman spectroscopy, FT-IR, FESEM, HRTEM, and XPS confirmed the successful formation of phase-pure MgCo2O4 with varied morphologies. Among the synthesized materials, the freeze-dried sample exhibited a well-defined hollow-sphere structure, providing abundant electroactive sites and superior electron/mass transport pathways. This morphology contributed to outstanding electrocatalytic performance. For the oxygen evolution reaction (OER), the hollow-sphere MgCo2O4 catalyst demonstrated a low overpotential of 430 mV at 10 mA cm−2 and a Tafel slope of 190 mV dec−1. In addition, the same catalyst exhibited excellent activity for the urea oxidation reaction (UOR), with a Tafel slope of 95 mV dec−1 and enhanced current density under alkaline conditions. The superior UOR activity, enabled by the lower oxidation potential of urea (∼0.37 V vs. RHE), also highlights its potential for energy-efficient hydrogen production and wastewater treatment. This work establishes a scalable and cost-effective strategy to synthesize high-performance MgCo2O4 hollow-sphere electrocatalysts, paving the way for their application in sustainable energy and environmental technologies.
Citation
Sustainable Materials and Technologies, 45, 2025