A stack-guiding unit constructed 2D COF with improved charge carrier transport and versatile photocatalytic functions

Two-dimensional COFs have shown great potential in photocatalysis, and the ordered layer arrangement is vital for the efficient utilization of photogenerated charge carriers. Herein, with a twisted knot of hexabenzocoronene, an ultrastable dioxin-linked 2D COF with undulated lattice was synthesized. As evidenced by N2 sorption, optoelectrochemical and transient absorption experiments and theoretical calculation, the concave-convex complementarity between layers effectively prevents stacking dislocation, prolongs the donor/acceptor π-columnar arrays and thus facilitates the transport of charge carriers. This COF was successfully applied to a series of photocatalytic reactions, such as the degradation of pollutants, the oxidative hydroxylation of arylboronic acids and the reduction of CO2. The activity exhibited by this COF in all the photocatalytic systems was obviously superior to the planar counterpart. The results of this work illustrate that the incorporation of stack-guiding building blocks is an effective strategy to improve the photocatalytic performance of COF materials.