Integrated Quasiplane Heteronanostructures of MoSe2/Bi2Se3 Hexagonal Nanosheets: Synergetic Electrocatalytic Water Splitting and Enhanced Supercapacitor Performance

MoSe2 as a typical transition metal dichalcogenide holds great potential for energy storage and catalysis but its performance is largely limited by its poor conductivity. Bi2Se3 nanosheets, a kind of topological insulators, possess gapless edges on boundary and show metallic character on surface. According to the principle of complementary, a novel integrated quasiplane structure of MoSe2/Bi2Se3 hybrids is designed with artistic heteronanostructures via a hot injection in colloidal system. Interestingly, the heteronanostructures are typically constituted by single‐layer Bi2Se3 hexagonal nanoplates evenly enclosed by small ultrathin hierarchical MoSe2 nanosheets on the whole surfaces. X‐ray photoelectron spectroscopy investigations suggest obvious electron transfer from Bi2Se3 to MoSe2, which can help to enhance the conductivity of the hybrid electrode. Especially, schematic energy band diagrams derived from ultraviolet photoelectron spectroscopy studies indicate that Bi2Se3 has higher EF and smaller Φ than MoSe2, further confirming the electronic modulation between Bi2Se3 and MoSe2, where Bi2Se3 serves as an excellent substrate to provide electrons and acts as channels for high‐rate transition. The MoSe2/Bi2Se3 hybrids demonstrating a low onset potential, small Tafel slope, high current density, and long‐term stability suggest excellent hydrogen evolution reaction activity, whereas a high specific capacitance, satisfactory rate capability, and rapid ions diffusion indicate enhanced supercapacitor performance. Integrated quasiplane heteronanostructures of MoSe2/Bi2Se3 hexagonal nanosheets are fabricated via a hot injection process for the first time. Investigations suggest there is obvious electron transfer from Bi2Se3 to MoSe2, which can help enhance the conductivity of the hybrid electrode. Owing to synergistic structural features, the MoSe2/Bi2Se3 hybrids exhibit significantly enhanced electrocatalytic water splitting activity and supercapacitive performance.