Molecular self-assembly is a powerful method to synthesize nanostructured materials. The unique property of molecular assemblies has been shown to depend not only on the size, shape, and composition of the molecular building blocks but also to a large extent on ordered spatial arrangement within an assembly. The synthesis of hierarchical structures leveraging the structural advantages of individual molecules still remains a significant challenge. Here, we developed interfacially driven microemulsion (μ-emulsion) method and micelle-confined method to initiate self-assembly and formation of hierarchically structured porphyrin nanocrystals. An optically active macrocyclic building block meso-tetraphenyl porphine dichloride (TPP) with different metal core are used to initiate non-covalent self-assembly confined within µ-emulsion droplets. In-situ studies of dynamic light scattering, UV-vis spectroscopy, and TEM, as well as optical imaging suggest an evaporation-induced nucleation and growth self-assembly mechanism. The resulted nanocrystals exhibit uniform shapes and sizes form ten to hundred nanometers. Due to the spatial ordering of (M)TPP, the hierarchical nanocrystals exhibit collective optical properties resulted from molecular (M)TPP and photocatalytic reduction of platinum nanoparticles and networks.