Tuning the local chemical environment of ZnSe quantum dots with dithiols towards photocatalytic CO reduction.

Sunlight-driven CO reduction to renewable fuels is a promising strategy towards a closed carbon cycle in a circular economy. For that purpose, colloidal quantum dots (QDs) have emerged as a versatile light absorber platform that offers many possibilities for surface modification strategies. Considerable attention has been focused on tailoring the local chemical environment of the catalytic site for CO reduction with chemical functionalities ranging from amino acids to amines, imidazolium, pyridines, and others.

Imidazolium-modification enhances photocatalytic CO reduction on ZnSe quantum dots.

Colloidal photocatalysts can utilize solar light for the conversion of CO to carbon-based fuels, but controlling the product selectivity for CO reduction remains challenging, in particular in aqueous solution. Here, we present an organic surface modification strategy to tune the product selectivity of colloidal ZnSe quantum dots (QDs) towards photocatalytic CO reduction even in the absence of transition metal co-catalysts. Besides H, imidazolium-modified ZnSe QDs evolve up to 2.