1：Experimental Design and Method Selection:

The study involved synthesizing porous TiO2 from MIL-125 MOF, modifying it with MgO via ALD and Ag nanoparticles via photodeposition in different sequences (Ag/MgO/TiO2 and MgO/Ag/TiO2). The rationale was to explore synergistic effects on CO2 photoreduction. Methods included ALD for uniform MgO coating and photodeposition for Ag nanoparticle deposition.

2：2). The rationale was to explore synergistic effects on CO2 photoreduction. Methods included ALD for uniform MgO coating and photodeposition for Ag nanoparticle deposition. Sample Selection and Data Sources:

2. Sample Selection and Data Sources: Samples included pristine TiO2, single-modified TiO2 (with MgO or Ag), and co-modified TiO2 with varying MgO layers (1-10 ALD cycles) and fixed Ag content (5 wt.%). Data sources were experimental measurements from characterization and performance tests.

3：List of Experimental Equipment and Materials:

Equipment included ALD system (Ultratech Savannah S200), UV lamp (100 W, 365 nm), Xe lamp (450 W), XRD (Bruker-AXS D8 Advance), SEM (JEOL JSM7500F), TEM (FEI Tecnai G2 F20 ST), XPS (Omicron XPS system), UV-vis spectrophotometer (Hitachi U4100), photoluminescence spectrometer (PTI QuantaMaster), GC (Shimadzu GC-2014ATF), potentiostat (Gamry Reference 3000). Materials included TiO2, Mg precursor (bis(ethylcyclopentadienyl) magnesium), AgNO3, glass fiber filter paper, CO2 gas, etc.

4：0). Materials included TiO2, Mg precursor (bis(ethylcyclopentadienyl) magnesium), AgNO3, glass fiber filter paper, CO2 gas, etc. Experimental Procedures and Operational Workflow:

4. Experimental Procedures and Operational Workflow: Procedures included synthesis of TiO2, ALD coating of MgO, photodeposition of Ag, calcination, characterization (XRD, SEM, TEM, XPS, UV-vis, PL), CO2 photoreduction testing (with gas flow and irradiation), and electrochemical measurements (photocurrent, EIS).

5：Data Analysis Methods:

Data analysis involved calculating product yields, promotion factors, electron numbers, and using techniques like Rietveld refinement for XRD, deconvolution for XPS, and impedance analysis for EIS.