Pt-deposited NiEr layered double hydroxide for efficient trifunctional electrocatalysis toward overall water splitting and rechargeable zinc-air batteries

Trifunctional electrocatalysts for OER, HER, and ORR are highly desirable for integrated energy conversion and storage. Herein, a Pt-deposited NiEr layered double hydroxide electrode on nickel foam, denoted as NiErPt-LDH@NF, is developed as an efficient trifunctional electrocatalyst in alkaline media. NiErPt-LDH@NF delivers 307 mV for OER at 10 mA cm −2 , 15.7 mV for HER at 10 mA cm −2 , and an ORR E onset /E 1/2 of 0.94/0.92 V, together with fast kinetics, low charge-transfer resistance, and good durability. The superior performance originates mainly from the electronic interaction between Er and Pt, the resulting increase in electron density at Pt sites, and the formation of dual Pt-containing active phases that promote interfacial charge transfer. A symmetric alkaline electrolyzer based on NiErPt-LDH@NF requires only 1.82 V to reach 40 mA cm −2 and exhibits excellent operational stability, while a rechargeable zinc-air battery using NiErPt-LDH@NF as the air cathode delivers an open-circuit voltage of 1.488 V and a peak power density of 160.82 mW cm −2 . This work demonstrates that rare-earth metal-Pt coupling is an effective strategy for constructing multifunctional electrocatalysts for integrated energy applications.