High-index facets exposed on metal-organic framework for boosting photocatalytic carbon dioxide reduction

Facets exposed on metal-organic frameworks (MOFs) are considered to be responsible for the efficiency of photocatalytic CO2 conversion. Here, NH2-MIL-125(Ti) with exposed high-index {1 1 2} facets has been investigated in detail for photocatalytic CO2 reduction. Compared with low-index facets, the high-index {1 1 2} facets exhibit superior activity for CO2-to-CO and CO2-to-CH4 conversions, which are 33 and 31 times higher for CO and CH4 productions than the {00 1}/{1 1 1} facets. The superior photocatalytic activity is attributed to the large CO2 uptake, efficient photoexcitation, charge separation and migration behaviors of the NH2-MIL-125(Ti) with exposing high-index facets. This study provides an effective strategy to develop MOFs catalysts via facet engineering for targeted performance.