Evaluation of Dy–Cr integration in MOF/rGO nanocomposite for enhanced electrochemical water splitting

Abstract The development of stable, cost-effective electrocatalysts for water splitting is critical for enhancing hydrogen energy systems, particularly for the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER). Metal-organic frameworks (MOFs) show great promise due to their tunable structures, high surface areas, and ability to optimize active sites for both HER and OER, improving catalytic efficiency. This study synthesizes a composite material of dysprosium–chromium MOF and reduced graphene oxide (Dy–Cr-MOF/rGO) through a simple hydrothermal method. The Dy–Cr-MOF/rGO composite exhibited exceptional electrocatalytic performance, achieving an OER overpotential of 164 mV and HER overpotential of 158 mV, with Tafel slopes of 42 mV dec-1 and 32 mV dec-1, respectively. After 50 h of continuous operation in a two-electrode system, the composite maintained stable Tafel slopes of 108 mV dec-1 (OER) and 87 mV dec-1 (HER). Practical device tests further confirmed the stability and robustness of the composite, highlighting its potential for scalable applications in electrochemical energy conversion systems. These results demonstrate that Dy–Cr-MOF/rGO is a promising bifunctional electrocatalyst for efficient water splitting.