Tubular ZIF@mesoporous polydopamine composite with enhanced catalytic activity for photo-driven CO2 fixation

The design presented here involves zeolitic imidazolate framework (ZIF) nanotubes wrapped with a mesoporous polydopamine (mPDA) layer to merge the structural and textural merits of both materials for efficient CO 2 fixation at room temperature under solvent-free and light irradiation conditions. The resulting tubular Zn-ZIF@mPDA composite (ZZ@mPDA) demonstrates significantly improved catalytic activity in CO 2 cycloaddition with epichlorohydrin, achieving a selectivity of > 99 % and a high yield of 96.9 % at 18 h, which is superior to that of pristine Zn-ZIF, with a yield of only 51.4 %. In addition, the mPDA layer confers good structural and chemical stability to ZZ@mPDA, resulting in negligible catalytic activity loss after five cycles. A mechanistic study indicates that the superior catalytic performance of ZZ@mPDA can be attributed to the combined photothermal and photocatalytic effects, involving the participation of both Lewis acidic/basic sites and photo-induced electron/hole pairs in the activation of CO 2 and epoxides. This research demonstrates the potential of ZIF@mPDA for photo-driven CO 2 conversion to cyclic carbonates and offers insights into the underlying mechanism.