PNNL

Abstract

Numerous inorganic materials have been identified as potential candidates for high-performance photocatalysts. However, their solar-to-energy conversion efficiencies still fail to meet commercial requirements. The main hurdle is the rapid recombination of photoexcited electrons and holes in single-phase materials. A viable predicted approach to suppress charge recombination is coupling two materials to form a two-dimensional (2D) heterostructure that physically separates photoinduced electrons and holes in different layers. In this work, the heterostructure-based paradigm was tested and a scalable solution synthesis of epitaxial ZnO-MoS2 heterostructure was developed. A 2D ZnO-MoS2 heterostructure was synthesized under hydrothermal conditions by stabilizing intermediate Zn-hydroxide states on a functionalized MoS2 surface. Detailed characterization showed the formation of multilayer heterostructure with MoS2 flakes intercalated between large size ZnO plates. The performance of this heterostructure was evaluated using photocatalytic degradation of rhodamine B. A degradation efficiency of 70?% was measured within 90 minutes of visible-light irradiation, almost doubling the efficiency of the corresponding single-phase materials or their physical mixtures.