1：Experimental Design and Method Selection:

The study involved synthesizing a manganese complex and BiOI semiconductor, anchoring them via covalent bonds using carboxyl groups, and testing their photocatalytic activity for CO2 reduction under visible light. The rationale was to combine the light-harvesting ability of BiOI with the catalytic efficiency of the Mn complex.

2：Sample Selection and Data Sources:

Samples included synthesized fac-[Mn{4,4’-(COOH)2-2,2’-bipyridine}(CO)3Br] ([Mn]), BiOI prepared via hydrothermal method, and the hybrid [Mn]@BiOI. Data were obtained from characterization techniques and photocatalytic reactions.

3：List of Experimental Equipment and Materials:

Equipment included UV-2600 spectrophotometer (Shimadzu), 500 MHz Bruker Avance NMR spectrometer, Quattro Micro API mass spectrometer, CHI660d electrochemical workstation, SEM-EDS, 300 W Xe lamp with cutoff filters, gas chromatography (GC), and ion chromatography. Materials included Bi(NO3)3, KI·5H2O, ethylene glycol, acetonitrile, H2O, TEOA (triethanolamine), CO2, N2, and various chemicals for synthesis.

4：Experimental Procedures and Operational Workflow:

Synthesis of [Mn] involved reacting 2,2′-bipyridine-4,4′-dicarboxylic acid with Mn(CO)5Br in ethanol at 75°C. BiOI was synthesized by dissolving Bi(NO3)3 and KI·5H2O in ethylene glycol, heating at 120°C for 12h. The hybrid was prepared by stirring [Mn] and BiOI in acetonitrile overnight. Photocatalytic reactions were conducted in tubes with aqueous acetonitrile solutions containing 5% H2O and TEOA, saturated with CO2, irradiated with visible light (λ > 420 nm), and products analyzed by GC and ion chromatography.

5：2h. The hybrid was prepared by stirring [Mn] and BiOI in acetonitrile overnight. Photocatalytic reactions were conducted in tubes with aqueous acetonitrile solutions containing 5% H2O and TEOA, saturated with CO2, irradiated with visible light (λ > 420 nm), and products analyzed by GC and ion chromatography. Data Analysis Methods:

5. Data Analysis Methods: Data were analyzed using UV-vis spectra, NMR, mass spectrometry, Mott-Schottky plots for flat-band potential, SEM-EDS for element mapping, and statistical averaging of TON values from at least three acquisitions.