Hollow Plasmonic P‐Metal‐N S‐Scheme Heterojunction Photoreactor with Spatially Separated Dual Cocatalysts toward Artificial Photosynthesis

Abstract Semiconductor‐based step‐scheme (S‐scheme) heterojunctions possess many merits toward mimicking natural photosynthesis. However, their applications for solar‐to‐chemical energy conversion are hindered by inefficient charge utilization and unsatisfactory surface reactivity. Herein, two synergistic protocols are demonstrated to overcome these limitations based on the construction of a hollow plasmonic p‐metal‐n S‐scheme heterojunction photoreactor with spatially separated dual noble‐metal‐free cocatalysts. On one side, plasmonic Au, inserted into the heterointerfaces of CuS@ZnIn 2 S 4 core–shell nanoboxes, not only accelerates the transfer and recombination of useless charges, enabling a more thorough separation of useful ones for CO 2 reduction and H 2 O oxidation but also generates hot electrons and holes, respectively injects them into ZnIn 2 S 4 and CuS, further increasing the number of active carriers participating in redox reactions. On the other side, Fe(OH) x and Ti 3 C 2 cocatalysts, separately located on the CuS and ZnIn 2 S 4 surface, enrich the redox sites, adjust the reduction potential and pathway for selective CO 2 ‐to‐CH 4 transformation, and balance the transfer and consumption of photocarriers. As expected, significantly enhanced activity and selectivity in CH 4 production are achieved by the smart design along with nearly stoichiometric ratios of reduction and oxidation products. This study paves the way for optimizing artificial photosynthetic systems via rational interfacial channel introduction and surface cocatalyst modification.