Selective photocatalytic CO(2) reduction in aerobic environment by microporous Pd-porphyrin-based polymers coated hollow TiO(2)

Direct photocatalytic CO(2) reduction from primary sources, such as flue gas and air, into fuels, is highly desired, but the thermodynamically favored O(2) reduction almost completely impedes this process. Herein, we report on the efficacy of a composite photocatalyst prepared by hyper-crosslinking porphyrin-based polymers on hollow TiO(2) surface and subsequent coordinating with Pd(II). Such composite exhibits high resistance against O(2) inhibition, leading to 12% conversion yield of CO(2) from air after 2-h UV-visible light irradiation. In contrast, the CO(2) reduction over Pd/TiO(2) without the polymer is severely inhibited by the presence of O(2) ( ≥ 0.2 %). This study presents a feasible strategy, building Pd(II) sites into CO(2)-adsorptive polymers on hollow TiO(2) surface, for realizing CO(2) reduction with H(2)O in an aerobic environment by the high CO(2)/O(2) adsorption selectivity of polymers and efficient charge separation for CO(2) reduction and H(2)O oxidation on Pd(II) sites and hollow TiO(2), respectively.