Self-assembly of urchin-like porphyrin/graphene microspheres for artificial photosynthetic production of formic acid from CO2

Life runs on energy and natural resources of energy are being used quickly. Artificial photosynthesis, in which sunlight is used to produce valuable chemicals from abundant natural resources, is considered as one of the auspicious ways to meet the current energy requirements. Here we report a 5,10,15,20-tetrakis(4-aminophenyl)porphyrin/graphene (TkisAPP/G) based photocatalyst with a significant and sensible design and structure for the production of formic acid from CO2. The urchin-like TkisAPP/G microspheres show remarkable enhancement in sunlight absorption and improve the light-harvesting efficiency. An effective approach has been adopted for electronic coupling to develop covalent bonding between porphyrin and graphene which increases the rate of the photoinduced charge transfer. For the fabricated photocatalyst, a 0.5% solar-to-formic acid conversion efficiency has been attained which is greater than that of natural photosynthesis.