Bioinspired catalytic pocket promotes CO-to-ethanol photoconversion on colloidal quantum wells.

Sluggish surface reaction is a critical factor that strongly governs the efficiency of photocatalytic solar fuel production, particularly in CO-to-ethanol photoconversion. Here, inspired by the principles underlying enzyme catalytic proficiency and specificity, we report a biomimetic photocatalyst that affords superior CO-to-ethanol photoreduction efficiency (5.5 millimoles gram hour in average with 98.2% selectivity) distinctly surpassing the state of the art. The key is to create a class of catalytic pocket, which contains spatially organized NH…Cu-Se(-Zn) multiple functionalities at close range, over ZnSe colloidal quantum wells. Such structure offers a platform to mimic the concerted cooperation between the active site and surrounding secondary/outer coordination spheres in enzyme catalysis. This is manifested by the chemical adsorption and activation of CO via a bent geometry, favorable stabilization toward a variety of important intermediates, promotion of multielectron/proton transfer processes, etc. These results highlight the potential of incorporating enzyme-like features into the design of photocatalysts to overcome the challenges in CO reduction.