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 {0 0 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.