While tremendous advances have been made in dimensionality‐dependent performances of inorganic‐based low‐dimensional nanostructures, paradigms concerning π‐conjugated molecule‐based supramolecular nanoassemblies are relatively fewer despite their various intrinsic advantages. It is herein reported that 0D, 1D, and 2D supramolecular nanostructures of a porphyrin, 5,10,15,20‐tetrakis(4‐aminophenyl)‐21H,23H‐porphine, with a spherical, fibrous and sheetlike architecture, respectively, could be fabricated via a reprecipitation protocol. As a typical example to demonstrate their dimensionality‐dependent optoelectronic performances, it is shown that the nanomaterials could serve as photocatalysts for water remediation, where the catalytic reactivity exhibits a trend of nanofibers>nanospheres>nanosheets. The superior catalytic reactivity of the nanofibers stems from the formation of relatively well‐defined J‐aggregates with orderly and tightly organized chromophores, conferring them with strong photoinduced electron–hole transport and separation capability. The higher catalytic reactivity of the nanospheres than nanosheets results from their larger specific surface area, which facilitates efficient accessibility of photogenerated charge carriers, although the porphyrins therein form unspecific J‐aggregates with disorderly and loosely stacked chromophores. The investigation likely initiates a simple method for π‐conjugated molecule‐based 0D, 1D and 2D nanoassemblies by using the same tectons, based on which the highlighted underlying scientific insights might provide useful clues for rational design of organic‐based low‐dimensional advanced soft materials.

A key to understand relationships between structure and activity is help for rational designing high active catalytic films. In this research, a new bi‐cyclometallic ferrocene imine Pd(II)/Cu(II) catalytic monolayer supported on graphene oxide (GO@Fcl−Pd/Cu) was fabricated, which exhibited a higher activity (TOF=1.48×106 h−1) in Suzuki coupling reaction. Enhanced higher activity was related to the in situ formed Pd/ Cu2O (CuO) active centre on the surface during catalysis. Fe in ferrocene had the redox ability for making Pd0 more stability, meaning that Fe3+ was electron withdraw or donor during catalytic process, which could tune the electronic properties of the Pd and Cu in one complex and improve their electronic transferring to boost the activity. CuO/Cu2O could make Pd0 more negative and stability. Ensemble synergistic effect, including the metals, metal oxide, ligand and GO could be described as that the electron transferred from GO via ferrocene to Pd or via Cu(II) to Pd made more negative, improving the oxidative addition. Meanwhile, aryl boronic acid adsorbed on the vicinal Cu(II), Cu2O and CuO around Pd0 synergetic reaction easily with the Pd intermediate to form next intermediate.