Modulating the Selectivity of CO<sub>2</sub> Photoreduction by Regulating the Location of PtCu in a UiO-66@ZnIn<sub>2</sub>S<sub>4</sub> Core–Shell Nanoreactor
Zengrong Li, Peng Wang, Chunxia Ren, Linyi Wu, Yangtao Yao, Shuxian Zhong, Hongjun Lin, Leihong Zhao, Yijing Gao, Song Bai
Abstract
Controlling product selectivity in CO 2 photoreduction remains a grand challenge, particularly when CH 3 OH is the targeted product. Herein, we demonstrate a strategy for tuning the selectivity of core–shell-structured UiO-66@ZnIn 2 S 4 (UiO/ZIS) in visible-light-driven catalytic reduction of CO 2 by regulating the location of PtCu cocatalysts. The PtCu nanoparticles are confined within the inner UiO-66 core to afford PtCu/UiO/ZIS, incorporated at the UiO-66/ZnIn 2 S 4 heterointerface to form UiO/PtCu/ZIS, and anchored on the outer ZnIn 2 S 4 surface to fabricate UiO/ZIS/PtCu. The primary CO 2 reduction products for PtCu/UiO/ZIS, UiO/PtCu/ZIS, and UiO/ZIS/PtCu are CO, CH 3 OH, and CH 4, with selectivities of 52.1, 72.7, and 88.8%, respectively. Experimental and theoretical results demonstrate that the spatial position of PtCu affects both the charge separation efficiency and the H 2 O oxidation rate in the ternary photocatalysts. This, in turn, influences the supply of electrons and protons to the active sites, leading to varying degrees of CO 2 hydrogenation and deoxygenation. Additionally, different PtCu positions also create distinct reactive sites and surrounding microenvironments, altering the energy barriers of key reaction steps and giving rise to diverse CO 2 reduction pathways. This work provides fresh hints for rationally controlling product selectivity in artificial photosynthesis through the precise regulation of cocatalyst placement within heterostructured photocatalysts.