ZnFe layered double hydroxide-modified porous MoTe2 and NiTe nanosheet composites as self-supporting electrodes for achieving efficient overall water splitting

Abstract

Hydrogen, with its high energy density and low-emission combustion, is key to future energy systems. Water electrolysis provides a sustainable hydrogen production route, but its efficiency depends on electrocatalyst performance. To address this, we develop a self-supported, multilevel heterostructured electrode (ZFMN/NF) consisting of a porous MoTe₂ and NiTe nanosheet composite modified with ZnFe-layered double hydroxides (ZnFe-LDHs). This design enhances both HER and OER kinetics through hierarchical nanostructuring, interfacial electronic modulation, and a binder-free configuration. DFT calculations show that the ZnFe-LDH–MoTe₂–NiTe heterojunction optimizes electron transfer, while the 3D porous framework improves mass transport. The ZFMN/NF electrode achieves low overpotentials of 90 mV (HER) and 179 mV (OER) at 10 mA cm⁻², enabling overall water splitting at 1.54 V, 4.3% lower than the Pt/C‖RuO₂ system. Long-term stability tests show minimal increases in overpotentials (0.7% and 1.5% after 1000 and 3000 CV cycles, respectively). The CO₃²⁻-intercalated ZnFe-LDH enhances stability and durability. This work offers an effective strategy for developing non-noble-metal electrocatalysts for efficient and durable water splitting.