Hydrogen evolution using a self-supported starch carbon aerogel electrocatalyst loaded with CeO2–MoxC in alkaline saline water†
Abstract
Hydrogen is a vital source of clean energy, which has gradually emerged as a prominent research topic. Design and development of active, stable, and low-cost electrocatalysts are essential prerequisites for achieving large-scale hydrogen production. In this study, a cost-effective, high-performance hydrogen evolution catalyst was developed by creating a porous carbon aerogel (CeO2–MoxC/PSCA) using starch and molybdenum salts, followed by the addition of CeO2 through a hydrothermal method. Detailed analyses using scanning electron microscopy (SEM), X-ray diffraction (XRD), Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS) confirmed that nitrogen doping generated additional defects on the carbon surface, thereby enhancing the active sites for hydrogen evolution. The incorporation of CeO2 improved the conductivity and hydrolysis ionization resulting in optimization of ΔGH*. The electrochemical test results revealed that in 1.0 M KOH, a current density of 10 mA cm−2 corresponded to an overpotential of 63 mV and a Tafel slope of 24.6 mV dec−1. In 1.0 M KOH + 0.5 M NaCl, at a current density of 10 mA cm−2, the overpotential increased to 79 mV, and the Tafel slope decreased to 21.4 mV dec−1. These results suggest that CeO2–MoxC/PSCA-3-900 exhibits excellent catalytic performance in both alkaline and alkaline saline solutions.