In summary, the ultrathin multimetallic phosphochalcogenide photocatalysts exhibit excellent photocatalytic activity. Among them, the ultrathin structure can provide more active sites, which is conducive to CO₂ adsorption and activation, while the Cu–In dual sites act as tandem catalytic sites to accelerate C=O bond activation and C–C bond coupling. Despite this research has immense scientific value and theoretical significance for achieving carbon emission reduction and resource utilization of CO₂ as well as guiding the design and preparation of highly efficient multimetallic 2D layered catalysts, the bottlenecks of large-scale preparation and the considerations on cost, stability and longevity of these 2D catalysts for industrial applications still remain a significant challenge. Furthermore, improving product selectivity and integrating such catalytic processes into existing industrial systems will make a substantial contribution to sustainable industrialization.