recombination of photogenerated charges, as well as limited catalytic reactivity and stability. [9] As a result, various approaches including constructive bandgap engineering, [10] defect engineering, [11] junction engineering, [12] and morphology control, have been proposed to enhance the photocatalytic CO 2 reduction performance. Among them, morphology control strategy could obtain multi-dimensional structures such as 0D quantum dots, 1D nanorods/nanowires, 2D nanosheets, and 3D porous/hollow structures or core-shell structures. [13,14] A great deal of work confirmed that photocatalysts with different morphologies exhibited better photocatalytic activity than bulk nanomaterials. [15] These structurally modified materials have attracted considerable interest in the field of photocatalysis owing to their large specific surface area, improved light absorption, and shortened charge carrier transport pathways. [14,16] Notably, because of the low density, tunable capacity, and molecular loading of hollow shell structures, core/yolk-shell nanoparticles have been extensively developed. [17] This special morphology contains both inner and outer surfaces, which can provide a superior platform for the deposition of other components. The activity of nano-semiconductor photocatalytic reduction of CO 2 has been significantly promoted through the construction of the core-shell structure.Recently, many hierarchical systems of core-shell structures have been designed and fabricated. Due to the unique sizedependent electronic, optical, and adsorption properties, coreshell structured nanomaterials have broad applicability. [18] Nowadays, with the increasing interest in core-shell catalysts, their definition has been extended to include structures with distinct boundaries between the two or more constituent materials, whereby the inner materials are partially or completely encapsulated (even chemically bonded) by the outer materials. Semiconductor materials [19] have been characterized by good optical and chemical properties, making them ideal candidates for photocatalytic energy conversion applications. Core-shell semiconductor materials of single-layer or multi-layer shell structures could be synthesized using the template method, precipitation method, or hydrothermal method. Metals (such as Ag, Au, Cu, and Pt) or metal alloys could be used as cores to integrate with other catalytic materials to form single-core or multicore structures. [20,21] Materials such as layered double hydroxides (LDHs) [22] and MXenes [23] have been the most commonly Photocatalytic CO 2 conversion into solar fuels is a promising technology to alleviate CO 2 emissions and energy crises. The development of core-shell structured photocatalysts brings many benefits to the photocatalytic CO 2 reduction process, such as high conversion efficiency, sufficient product selectivity, and endurable catalyst stability. Core-shell nanostructured materials with excellent physicochemical features take an irreplaceable position in the field of photocatalytic CO 2 reduc...