Interface modulation induced by the 1T Co-WS2 shell nanosheet layer at the metallic NiTe2/Ni core–nanoskeleton: Glib electrode-kinetics for HER, OER, and ORR

Abstract

The metallic (1T) transition metal dichalcogenides (TMDCs) are known for their superior electrocatalytic performance, due to their high conductivity, active basal-planes, and exposed edges. Our novel approach of coupling a metallic-NiTe2/Ni nano-skeleton with 1T-Co-WS2 nanosheet in a core–shell arrangement to develop a hybrid heterostructure (1T Co-WS2/NiTe2/Ni) has helped to outperform the trifunctional-electrocatalytic activity (HER, OER, and ORR). 1T-Co-WS2/NiTe2/Ni only requires ultralow overpotential (ηHER = 88 mV@10, ηOER = 290 mV@30), higher half-wave potential for ORR (E1/2 = 0.781 V vs RHE), small Tafel slopes (HER = 68 mV dec-1, OER = 98 mV dec-1, and ORR = 63 mV dec-1) with high electrocatalytic surface area and robust stability in corresponding half-cell reactions. The designed heterostructured electrocatalyst (1T Co-WS2/NiTe2/Ni) presented exceptional total water-splitting performance, requiring a low voltage of 1.521 V to yield 10 mA cm−2 current with extensive structural and electrochemical durability. Such performance could be attributed towards improved nanochannel morphology with exposed active edge, fluent electrode-kinetics, facile adsorption–desorption of reaction intermediates owing to the intrinsically tuned 1T-WS2 by cobalt-doping, and hybridized NiTe2/Ni nano-skeleton. The DFT study confirmed that the incorporation of Co atoms in basal plane and the edge sites of WS2 lattice induces the redistribution and modulation of electronic structure for fast electron/charge transfer and the synergistic coupling of 1T NiTe2 heterostructures bolstered the electrocatalytic activity of the as-prepared catalysts. These outcomes provide a prospect towards the design and application of efficient 2D/2D heterostructured electrocatalyst for zero emission energy goal.