Vacancy-Engineered\n1D Nanorods with Spatially Segregated\nDual Redox Sites for Visible-Light-Driven Cooperative CO<sub>2</sub> Reduction

Cooperative CO<sub>2</sub> photoreduction with tailored\norganic\nsynthesis offers a potent avenue for harnessing concurrently generated\nelectrons and holes, facilitating the creation of both solar fuels\nand specialized chemical compounds. However, controlling the crystallization\nand morphologies of metal-free molecular nanostructures with exceptional\nphotocatalytic activities toward CO<sub>2</sub> reduction remains\na significant challenge. These hurdles encompass insufficient CO<sub>2</sub> activation potential, sluggish multielectron processes, delayed\ncharge-separation kinetics, inadequate storage of long-lived photoexcitons,\nunfavorable thermodynamic conditions, and the precise control of product\nselectivity. Here, melem oligomer 2D nanosheets (MNSs) synthesized\nthrough pyrolysis are transformed into 1D nanorods (MNRs) at room\ntemperature with the simultaneous engineering of vacancies and morphology.\nTransient absorption spectral analysis reveals that vacancies in MNRs\ntrap charges, extending charge carrier lifetimes. Additionally, carbon\nvacancies enhance CO<sub>2</sub> adsorption by increasing amine functional\ncenters. The photocatalytic performance of MNRs for CO<sub>2</sub> reduction coupled with benzyl alcohol oxidation is approximately\nten times higher (CH<sub>3</sub>OH and aromatic aldehyde production\nrate 27 ± 0.5 and 93 ± 0.5 mmol g<sup>–1</sup> h<sup>–1</sup>, respectively) than for the MNSs (CH<sub>3</sub>OH\nand aromatic aldehyde production rate 2.9 ± 0.5 and 9 ±\n0.5 mmol g<sup>–1</sup> h<sup>–1</sup>, respectively).\nThe CO<sub>2</sub> reduction pathway involved the carbon-coordinated\nformyl pathway through the formation of *COOH and *CHO intermediates,\nas mapped by <i>in situ</i> Fourier-transform infrared spectroscopy.\nThe superior performance of MNRs is attributed to favorable energy-level\nalignment, enriched amine surfaces, and unique morphology, enhancing\nsolar-to-chemical conversion.