Nature’s leaf is the smart flexible photocatalytic system that can continuously carry out the chemical transformation without the need of catalyst regeneration and enable efficient sunlight harvesting for solar-to-chemical energy conversion. Inspired by this sustainable Nature’s photosynthesis, this thesis has demonstrated the development of a few 2D flexible photocatalysts based on plasmonic multifunctional nanostructures that can offer continuous solar-to-chemical conversion, omnidirectional sunlight harvesting, and low-intensity sunlight-irradiated photocatalysis. It indicates the significance of the combination of nanoscale materials synthesis and macroscopic device design for future-generation artificial photosynthesis.