Porphyrin nanoriber bundles (see figure) are synthesized by a novel phase-transfer ionic self-assembly technique, allowing the use of a wide range of water-insoluble porphyrin tectons. Their photocatalytic self-metallization with Pt, An, Ag, or Pt-Au alloys result in unusual porphyrin-metal composite nanostructures with potential applications in catalysis, sensing, and solar hydrogen production.