Factorial Design and Performance of a Hierarchical Floret-like Triplex LDH Composite in Facilitating the Oxygen and Hydrogen Evolution Reactions

The triplex (trimetallic) layered double hydroxide (LDH) possesses unique composition and structural properties, signifying it as a novel electrode material for the oxygen and hydrogen evolution reactions. This work presents the strategic integration of 0D (CDs) and 2D (gC₃N₅/gC₃N₄) materials with triplex NCF-LDH (NiCoFe layered double hydroxide) to develop a novel hierarchical floret-like electrocatalyst, NCF-LDH/GCN5/CDs. Substantial augmentations in the electrocatalytic behavior of NCF-LDH/GCN5/CDs and their counterpart NCF-LDH/GCN4/CDs are revealed by in-depth structural, morphological, and compositional investigations. Notably, the NCF-LDH/GCN5/CDs composite outperforms the NCF-LDH/GCN4/CDs version in terms of bifunctional electrocatalytic activity, exhibiting low overpotentials of 236 mV (OER) and 208 mV (HER) at 10 mA cm^-2. Despite the fact that NCF-LDH/GCN4/CDs demonstrate a commendable overpotential of 230 mV for the HER and 250 mV for the OER, their diminished activity emphasizes the superior catalytic synergy in GCN5-based systems, which may be attributed to enhanced electronic transfer and active site availability. Furthermore, the chronoamperometric studies for overall water splitting reflect the good stability and catalytic activity of NCF-LDH/GCN5/CDs, with no significant loss over 50 h. This result signifies an interface engineered between triplex-LDH and GCN5, enabling significant charge migration and tunable electronic properties. The factorial design and function of the floret-like 2-fold electrocatalyst offer an innovative strategy to meet the critical demands in producing green hydrogen during the water electrolysis process.