Enhanced Photocatalytic Oxygen Evolution Using Copper-Coordinated Perylene Diimide Nanorod Assemblies.

A crystalline supramolecular photocatalyst is prepared through metal-induced self-assembly of perylene diimide with imidazole groups at the imide position (PDI-Hm). Exploiting the metal-coordination ability of imidazole, a crystalline assembly of copper-coordinated PDI-Hm (CuPDI-Hm) in a nanorod shape is prepared which displays an outstanding photocatalytic oxygen evolution rate of 25,900 µmol g-1 h-1 without additional co-catalysts. The imidazole-copper coordination, along with π-π stacking of PDI frameworks, guides the arrangement of PDI-Hm molecules to form highly crystalline assemblies. The coordination of copper also modulates the size of the CuPDI-Hm supramolecular assembly by regulating the nucleation and growth processes. Furthermore, the imidazole-copper coordination constructs the electric field within the PDI-Hm assembly, hindering the recombination of photo-induced charges to enhance the photoelectric/photocatalytic activity when compared to Cu-free PDI-Hm assemblies. Small CuPDI-Hm assembly exhibits higher photocatalytic activity due to their larger surface area and reduced light scattering. Together, the Cu-imidazole coordination presents a facile way for fabricating size-controlled crystalline PDI assemblies with built-in electric field enhancing photoelectric and photocatalytic activities substantially.

Highly Luminescent Shell-Less Indium Phosphide Quantum Dots Enabled by Atomistically Tailored Surface States.

Contrary to the prevailing notion that shell structures arise from the intricate chemistry and surface defects of InP quantum dots (QDs), an innovative strategy that remarkably enhances the luminescence efficiency of core-only InP QDs to over 90% is introduced. This paradigm shift is achieved through the concurrent utilization of group 2 and 3 metal-derived ligands, providing an effective remedy for surface defects and facilitating charge recombination. Specifically, a combination of Zn carboxylate and Ga chloride is employed to address the undercoordination issues associated with In and P atoms, leading to the alleviation of in-gap trap states. The intricate interplay and proportional ratio between Ga- and Zn-containing ligands play pivotal roles in attaining record-high luminescence efficiency in core-only InP QDs, as successfully demonstrated across various sizes and color emissions. Moreover, the fabrication of electroluminescent devices relying solely on InP core emission opens a new direction in optoelectronics, demonstrating the potential of the approach not only in optoelectronic applications but also in catalysis or energy conversion by charge transfer.