Artificial spherical chromatophore nanomicelles for selective CO2 reduction in water

Abstract

In nature, photosynthetic organelles harness solar radiation to produce energy-rich compounds from water and atmospheric CO2 via exquisite supramolecular assemblies. Although artificial photocatalytic cycles have been shown to occur at higher intrinsic efficiencies, the low selectivity and stability in water for multi-electron CO(2 )reduction hamper their practical applications. The creation of water-compatible artificial photocatalytic systems mimicking the natural photosynthetic apparatus for selective and efficient solar fuel production represents a major challenge. Here we show a highly stable and efficient artificial spherical chromatophore nanomicelle system self-assembled from Zn porphyrin amphiphiles with a Co catalyst in water for CO2-to-methane conversion with a turnover number >6,600 and 89% selectivity over 30 days. The hierarchical self-assembly induced a spherical antenna effect that could facilitate the photocatalytic process with an initial 15% solar-to-fuel efficiency. Furthermore, it has a capability to efficiently reduce atmospheric CO2 into methane with high selectivity in water.