Bimetallic carbides embedded in heteroatom-doped carbon nanotubes for efficient electrocatalytic hydrogen evolution reaction and high-performance lithium storage

A sacrifice-template strategy combined with carbonization treatment was rationally designed to fabricate tubular-like carbon nanotubes coupled with ultrasmall Mo-W bimetallic carbides for boosting electrocatalytic hydrogen evolution and lithium ions storage. Specifically, metal chelating coordination reaction and the dissolution of template undergo simultaneously under weak alkaline condition, thus leading to the formation of the hollow Mo-W-polydopamine (MoW-PDA) hybrid nanotubes. After carbonization, ultrasmall Mo-W bimetallic carbides embedded in the heteroatom (N, P)-codoped carbon nanotubes (Mo_xW_2-xC/N, P-codoped CNTs) endow to prevent the aggregation between nanoparticles and provide more active sites. As a proof of concept, Mo_xW_2-xC/N, P-codoped CNTs exhibited outstanding electrocatalytic activity toward hydrogen evolution reaction with a low overpotential and steady durability in acidic and alkaline solutions. Moreover, Mo_xW_2-xC/N, P-codoped CNTs displayed extraordinary lithium storage performance, which delivered decent reversible capacities of 560.9 mAh g⁻¹ and 366.6 mAh g⁻¹ at 1.0 A g⁻¹ and 5.0 A g⁻¹ after 1000 cycles, respectively, one of best performances for metal carbide-based anode. This work highlights a novel strategy to fabricate bifunctional carbides toward efficient electrocatalytic reaction and lithium ions storage.