Two-dimensional molybdenum trioxide nanoflakes wrapped with interlayer-expanded molybdenum disulfide nanosheets: Superior performances in supercapacitive energy storage and visible-light-driven photocatalysis

Two-dimensional layered molybdenum disulfide and molybdenum trioxide (α-MoO3) have fascinating potential for complementary energy storage and conversion applications due to their high surface area and multiple oxidation states of Mo. We report a novel hierarchical 1T/2H MoS2/MoO3 nanocomposite prepared by a scalable liquid-phase exfoliation and subsequent facile hydrothermal route. The growth of MoS2 onto 2D α-MoO3 creates a unique 2D/2D hierarchical structure, which reduces the aggregation of α-MoO3 nanoflakes, improves the electrical conductivity of the composite electrode, and activates inert basal plane of MoS2. The electrochemical measurements revealed that such a composite possessed higher specific capacitance and promoted capacitance retention in a symmetric supercapacitor assembly. The remarkably enhanced visible-light-driven photocatalytic performance of hybrid hierarchical architecture can be attributed to a few distinctive synergistic effects, including activated inert basal plane, facilitated interfacial charge transfer, and peculiar ultrathin nanosheet framework with a large surface area and high content of exposed edge sites.