Nitrogen doping regulated electron structure of CoTe1.8/FeNiTe2 heterojunction improved the electrocatalytic water splitting performance with excellent stability

The development of environmentally friendly, inexpensive, and highly active bifunctional catalysts for water splitting remains a major challenge. In this work, hierarchical bulk porous N–CoTe 1.8 /FeNiTe 2 interfacial catalysts were prepared for the first. The prepared three-dimensional (3D) self-supported nanomaterials exhibited efficient electron transfer and mass diffusion, in addition to the optimization of the electronic structure by N doping and the strong electronic interactions between CoTe 1.8 and FeNiTe 2 at the interface facilitated the rapid electron transfer. The layered and porous microtopography increases the specific surface area of the material accelerating the gas transport. The N–CoTe 1.8 /FeNiTe 2 exhibits excellent catalytic activity for OER and HER. It has low overpotentials of 170 mV and 56 mV at 10 mA cm −2 of current density in 1.0 M KOH. In addition, the Faraday efficiency for hydrogen and oxygen production was close to 100 %. The voltage across the water splitting system is only 1.51 V at 10 mA cm −2 current density and has excellent stability with no degradation in a stability test lasting 100 h at 100 mA cm −2 current density. This work provides a novel concept for the rational design and synthesis of inexpensive non-precious metal telluride-based water splitting electrocatalysts.