A Self-Standing 3D Heterostructured N-Doped Co₄S₃/Ni₃S₂/NF for High-Performance Overall Water Splitting

Abstract

Development of efficient electrocatalysts with earth-abundant materials for water splitting is of paramount significance for energy harvesting and storage. Here, novel nickel foam-supported nitrogen-doped Co4S3/Ni3S2 heterostructured nanosheets (denoted as N-Co4S3/Ni3S2/NF) were synthesized for water splitting. The self-standing 3D electrocatalysts consisting of Co4S3 nanocrystals and Ni3S2 nanosheets show an abundant interface of Co4S3/Ni3S2 and a high density of defects of nitrogen doping as catalytic active sites to improve electronic band structure and efficient charge transfer ability. The as-prepared N-Co4S3/Ni3S2/NF exhibits superior OER performance (overpotential of 331 mV at 100 mA cm−2) and enhanced HER performance (overpotential of 150 mV at 10 mA cm−2). Eventually, a high-performance electrolyzer (N-Co4S3/Ni3S2/NF//N-Co4S3/Ni3S2/NF) was assembled for overall water splitting with a low cell voltage of 1.647 V at 10 mA cm−2. The rational structural design and nitrogen doping present a wide range of possibilities for the further development of highly efficient electrocatalysts based on earth abundant elements.