Janus nanoarchitectures: From structural design to catalytic applications

Janus nanoarchitectures, an emerging class of nanostructures named after the Roman god having two faces, have been considered as a fascinating class of nanomaterials for promising applications in various areas, such as optical imaging, emulsion stabilizers, catalysis, drug delivery, etc. The asymmetric structures or counterparts of Janus nanostructures provide access to construct a single unit with multifunctional properties, and thus allow the design of nanocomposites with a possible synergistic effect, especially for catalytic reactions. In the last decade, Janus nanomaterials have been successfully applied in the field of catalysis, by providing solutions to some complex situations, such as biphasic reactions, catalysts recovery, self-propelled movements, and biocompatible catalysis. In this review, we intend to highlight the recent progress of Janus nanoarchitectures for the growing field of catalytic applications. Herein, the fabrication and catalytic applications of Janus nanoarchitectures are critically reviewed in terms of three categories of compositions, i.e., polymeric, inorganic, and polymeric/inorganic Janus nanostructures. Specifically, typical applications of Janus nanoarchitectures in micro/nano motors, interfacial catalysis, and photocatalytic reactions are summarized and discussed. An outlook of the future applications and possible further study of Janus nanomaterials is also provided.