A supported-catalyst of grafting [Co(TPA)Cl]Cl molecular catalyst onto SiO2 nanoparticles to achieve robust syngas production in a photochemical system

•A supported-catalyst SiO2-TPACo was synthesized and characterized.•The SiO2-TPACo catalyst exhibited daul-activity of CO2-to-CO and 2H+-to-H2 conversions in a photochemical system.•The noble-metal-free system produced syngas (H2 + CO) under visible light irradiation.•At optimal condition, the system produced 10.18 μmol syngas with a CO/H2 ratio of ca. 1:1 under visible light irradiation.•The photoinduced electron transfer from g-C3N4 to [Co(TPA)Cl]Cl moiety of SiO2-TPACo catalyst was studied and proposed.