be modified to complement a multitude of electrocatalytic processes. Structurally, Janus architectures can be determined by their characteristic compartmentalized structure with distinct functional domains. The compartmentalization of functional domains in the Janus material can minimize interference by different types of active sites in a Janus material, allowing the individual functional domains to preserve their intrinsic activity, giving Janus architectures their anisotropic properties, which are advantageous for multi-functional electrocatalysis. [5] The generalized Janus structure is shown in Figure 1. In light of the unique and advantageous characteristics of Janus materials, it is necessary to review and rethink their design strategies and future directions. Herein, this review provides a comprehensive insight into the unique catalytic benefits of Janus materials across various electrocatalytic reactions and commercial applications. Moreover, this review also proposes the prospects of Janus architecture for future exploration. The outline of the review is presented in Figure 2.
Janus Architecture: Structure, Synthesis, and Electrochemical Mechanism
Janus StructureJanus materials possess multiple interconnected functional domains which act as compartmentalized active sites [6][7][8] (Figure 3). Surface modification of Janus materials can also facilitate the conjugation of distinct chemical moieties with specific functionality, [9][10][11] allowing individual domains to retain their inherent activity, with little to no interference from other domains. These co-existing functional domains give Janus electrocatalysts their anisotropic properties, making them highly favorable for multi-functional electrocatalysis.
Janus SynthesisThe compartmentalized Janus structure can be created using two general techniques. The first technique involves the synthesis of a single catalyst structure with multiple active sites, one for each electrochemical half-reaction. Although this technique gives the structure great durability as a result of the single catalyst structure formation, however, this technique is complex and tough to accomplish due to the restricted number of catalysts with suitable active sites. Moreover, due to the concurrent formation of the single Janus structure, this technique Janus architectures have garnered great research efforts in recent years, leading to outstanding advances in electrocatalysis. Benefiting from the synergistic combination of their anisotropy which endows the manifestation of various co-existing electrochemical properties, and their compartmentalized structure that enables each functional domain to retain its inherent activity, with little to no interference from other domains, Janus architectures show great potential as exceptionally versatile electrocatalysts to complement a plethora of electrocatalytic processes. Thus, coupled with the growing interest in Janus architectures for electrocatalysis, it is imperative to investigate and reconsider their design strategies and future dire...