Graphitic Carbon Nitride-Supported Layered Double Hydroxides (GCN@FeMg-LDH) for Efficient Water Splitting and Energy Harvesting

Abstract

The advancement of highly efficient and cost-effective electrocatalysts for electrochemical water splitting, along with the development of triboelectric nanogenerators (TENGs), is crucial for sustainable energy generation and harvesting. In this study, a novel hybrid composite by integrating graphitic carbon nitride (GCN) with an earth-abundant FeMg-layered double hydroxide (LDH) (GCN@FeMg-LDH) was synthesized by the hydrothermal approach. Under controlled conditions, with optimized concentrations of metal ions and GCN, the fabricated electrode, GCN@FeMg-LDH demonstrated remarkably low overpotentials of 0.018 and 0.284 V and 0.101 and 0.365 V at 10 and 600 mA/cm² toward the hydrogen evolution (HER) and oxygen evolution (OER) reactions, respectively, in 1.0 M KOH. Furthermore, we leveraged the potential of the GCN@FeMg-LDH composite to develop a high-performance TENG suitable for practical electronic applications. The resulting GCN@FeMg-LDH-based TENG device, sized at 3 × 4 cm², demonstrated a substantial current output of 52 μA and a voltage output of 771 V. Notably, this TENG device exhibited an instantaneous power output of 5780 μW and exceptional stability, enduring over 15 000 cycles. Thus, this study concludes that the GCN@FeMg-LDH composite emerges as a superior candidate for applications in water splitting and TENGs, exhibiting significant promise for advancing clean energy technologies, in addition to lowering greenhouse gas emissions.