Abstract: A novel chiral photoanode was fabricated by in situ constructing surface molecular imprinting (MI) sites on vertically aligned single-crystalline (SC) ZnO, employing the l- or d-amino acid enantiomer as templates. The photoelectrochemical (PEC) experiments showed that the photoanode exhibited chiral recognition and enantioselective PEC oxidation ability to the template enantiomer, compared with the other one. The photocurrent response of l-Phe on the l-SC photoanode was 4.8 times the value of d-Phe. A similar result on the d-SC photoanode could also be observed. Moreover, it was found that the recognition factor obtained on the SC photoanode was 2.7-fold that of the polycrystalline counterpart. It was presumed that the enhanced PEC enantioselectivity may be attributed to the high-quality imprinting expression on the rigid surface of SC ZnO, on which the stereoselective adsorption ability was approximately 1.7 times that of the polycrystalline ZnO. The favorable photocatalytic activity of the one-dimensional SC photoanode further amplified the PEC chiral recognition ability by about 37%. Finally, the kinetics of PEC oxidation of the two enantiomers in racemic solution was investigated, and the rate constant on the proposed photoanode to the template enantiomer was above 1.75-fold that to the other enantiomer
Template and target information: l-phenylalanine, l-phe, d-phenylalanine, d-phe