Two-dimension on two-dimension growth: hierarchical Ni0.2Mo0.8N/Fe-doped Ni3N nanosheet array for overall water splitting†
Abstract
Developing advanced electrocatalysts with low cost for electrocatalytic water splitting are highly desirable. Herein, we report the design of two-dimension on two-dimension growth of hierarchical Ni0.2Mo0.8N nanosheets on Fe-doped Ni3N nanosheets supported on Ni foam (Ni0.2Mo0.8N/Fe–Ni3N/NF) via hydrothermal reaction and nitridation treatment. In the hierarchical structures, small Ni0.2Mo0.8N nanosheets were uniformly anchored on Fe–Ni3N nanosheets. Due to enhanced electron transfer between Ni0.2Mo0.8N and Fe–Ni3N, Ni0.2Mo0.8N/Fe–Ni3N/NF exhibits superior electrocatalytic activity for the oxygen evolution reaction (OER) and the hydrogen evolution reaction (HER). After stability tests for 50 h, Ni0.2Mo0.8N/Fe–Ni3N/NF exhibits negligible degradation of the current density for the OER (91% remain) and HER (95% remain), suggesting excellent stability. Owing to the outstanding performance, Ni0.2Mo0.8N/Fe–Ni3N/NF display a cell voltage of 1.54 V (10 mA cm−2) for electrocatalytic overall water splitting.