ABSTRACT Layered double hydroxides (LDHs) are prominent electrocatalysts for electro‐oxidation, leveraging direct electron transfer and radical species generation. However, their efficiency is limited by intrinsic activity and electron transfer capabilities. This study constructs a Ni(OH) 2 /NiFe‐LDH heterostructure anode to degrade refractory nickel‐organic complexes from electroless nickel plating (ENP) wastewater. This system achieved simultaneous complete oxidation of organics and nickel recovery, with a 96.9% chemical oxygen demand removal and a 71.4% Ni 2+ recovery rate within 2 h. Subsequently, the residual Ni 2+ was effectively immobilized using calcined CaAl‐LDH (CaAl‐500), enabling the effluent to meet discharge standards. Mechanistic investigations revealed that the Ni(OH) 2 modification significantly enhanced the electron transfer capability and increased the number of active sites on the LDH, while the oxygen vacancies in CaAl‐500 markedly promoted the isomorphic substitution of Ni 2+ . This coupled electrochemical oxidation and mineralization strategy provides an efficient and sustainable pathway for treating wastewater containing complex heavy metal–organic complexes.
Li et al. (2026) studied this question.