Two new chemically stable metalloporphyrin‐bridged metal‐catechol frameworks, InTCP‐Co and FeTCP‐Co, were constructed to achieve artificial photosynthesis without additional sacrificial agents and photosensitizers. The CO2 photoreduction rate over FeTCP‐Co considerably exceeds that obtained over InTCP‐Co, and the incorporation of uncoordinated hydroxyl groups, associated with catechol, into the network further promotes the photocatalytic activity. The iron‐oxo coordination chain assists energy band alignment and provides a redox‐active site, and the uncoordinated hydroxyl group contributes to the visible‐light absorptance, charge‐carrier transfer, and CO2‐scaffold affinity. With a formic acid selectivity of 97.8 %, FeTCP‐OH‐Co affords CO2 photoconversion with a reaction rate 4.3 and 15.7 times higher than those of FeTCP‐ Co and InTCP‐Co, respectively. These findings are also consistent with the spectroscopic study and DFT calculation. A series of hydro‐stable metalloporphyrin‐bridged metal‐phenate frameworks are constructed, which exhibit artificial photosynthetic activity under visible‐light irradiation without photosensitizer or sacrificial agent. Activity is boosted by substitution of the Fe‐oxo chain for an In‐oxo chain, and further enhanced by addition of the uncoordinated hydroxyl groups of catechol into the scaffold.