In this chapter, recent advances in photocatalytic CO 2 conversion with water and/or other reductants are reviewed for the publications between 2012 and 2015. Quantitative comparisons were made for the reaction rates in μmol h −1 g cat −1 to acertain the progress of this field although the rates depends on photocatalyst conditions and reaction conditions (temperature, pressure, and photon wavelength and flux). TiO 2 photoproduced methane or CO from CO 2 and water at rates of 0.1-17 μmol h −1 g cat −1 depending on the crystalline phase, crystalline face, and the defects. By depositing as minimal thin TiO 2 film, the rates increased to 50-240 μmol h −1 g cat −1 . Gaseous water was preferred rather than liquid water for methane/CO formation as compared to water photoreduction to H 2 . Pt, Pd, Au, Rh, Ag, Ni, Cu, Au 3 Cu alloy, I, MgO, RuO 2 , graphene, g-C 3 N 4 , Cu-containing dyes, and Cu-containing metal-organic frameworks (MOFs) were effective to assist the CO 2 photoreduction using TiO 2 to methane (or CO, methanol, ethane) at rates of 1.4-160 μmol h −1 g cat −1 . Metals of greater work function were preferred. By depositing as minimal thin photocatalyst film, the rates increased to 32-2200 μmol h −1 g cat −1 . The importance of crystal face of TiO 2 nanofiber was suggested. As for semiconductors other than TiO 2 , ZnO, Zn 6 Ti layered double hydroxide (LDH), Mg 3 In LDH, KTaO 3 , AgBr, carbon nanotube, and the composites of these were reported to form methane, CO, methanol, acetaldehyde from CO 2 and water at rates of 0.15-300 μmol h −1 g cat −1 that were comparable to rates using promoted TiO 2 . The band energy designs comprising appropriate conduction band for CO 2 reduction and valence band for water oxidation were made progresses in these semiconductors and semiconductor junctions in the three years. If H 2 was used as a reductant, Ni/SiO 2 -Al 2 O 3 formed methane at 423 K under pressurized CO 2 + H 2 at a rate of 55 mmol h −1 g cat −1 . This rate was not enabled by heating the system under dark, suggesting photoactivated reaction followed by thermally-assisted reaction(s) via Ni-H species. As pure photocatalytic reactions from CO 2 + H 2 , methanol formation rates were improved up to 0.30 μmol h −1 g cat −1 by the doping of Ag/Au nanoparticles, [Cu(OH) 4 ] 2− anions, and Cu-containing dyes to Zn-Ga LDH. Furthermore, sacrificial reductants, e.g. hydrazine, Na 2 SO 3 , methanol, triethanol amine, and triethyamine, were also utilized to form CO, formate, and methanol at rates of 20-2400 μmol h −1 g cat −1 using semiconductor or MOF photocatalysts. Finally, similar to the integrated system of semiconductor photocatalyst for water oxidation and metal complex/enzyme catalyst for CO 2 (photo)reduction, two semiconductors (WO 3 , Zn-Cu-Ga LDH) were combined on both side of proton-conducting polymer to form methanol at a rate of 0.05 μmol h −1 g cat −1 from CO 2 and moisture. These promotion of photoconversion rates of CO 2 and new photocatalysts found in these three years have indicated the way beyond for a new...