image: A molecularly compartmentalized photocatalyst with Fe-porphyrins on CNT exteriors and Ni-POMs inside channels enables vectorial electron transfer. Photoexcited electrons travel unidirectionally through CNTs to NiPOMs, efficiently driving CO2 to CO conversion with a 100% selectivity. This biomimetic architecture mimics natural photosynthesis, enhancing charge separation and achieving superior photocatalytic CO2 reduction under light.
Credit: ©Science China Press
A research team led by Professor Yong Ding at Lanzhou University has developed a new biomimetic photocatalyst that imitates the compartmentalized structure of natural photosynthesis to convert carbon dioxide (CO₂) into carbon monoxide (CO) with exceptional efficiency and selectivity.
In the study, Professor Ding’s group constructed a hierarchically ordered “inside–outside” carbon nanotube system in which nickel polyoxometalate (NiPOM) clusters are confined inside carbon nanotubes (CNTs) while iron porphyrin (FeTCPPOMe) molecules are anchored on the outer walls. This spatial configuration resembles the organization of photosynthetic membranes, where light-harvesting and catalytic centers are separated yet electronically connected.
Under simulated sunlight, the FeTCPPOMe–NiPOM@CNT catalyst achieved a CO production rate of 42.7 μmol g⁻¹ h⁻¹ with 100% selectivity, demonstrating far higher activity than conventional photocatalysts. The system channels photoexcited electrons generated by Fe-porphyrin units along a defined one-way path through the conductive CNTs toward the encapsulated NiPOM clusters, where CO₂ molecules are efficiently reduced.
According to Professor Ding, this engineered architecture creates a vectorial electron-transfer pathway that suppresses charge recombination and maximizes the use of solar energy. In-situ and quasi in-situ characterizations—including diffuse-reflectance infrared spectroscopy (DRIFTS), Kelvin probe force microscopy (KPFM), and X-ray photoelectron spectroscopy (XPS)—confirmed the directional migration of photogenerated carriers. Theoretical simulations supported the experimental observations, revealing continuous electron flow from FeTCPPOMe to NiPOM through the CNT backbone.
Professor Ding emphasized that the work provides a molecular-level model of how hierarchical organization can be exploited to achieve efficient artificial photosynthesis. The study demonstrates that combining polyoxometalate clusters, porphyrinic light absorbers, and conductive carbon frameworks can dramatically enhance photocatalytic performance for sustainable CO₂ utilization.
Author and Institutional Profile
Professor Yong Ding is a Ph.D. supervisor and Feitian Distinguished Professor at the College of Chemistry and Chemical Engineering, Lanzhou University, where he also serves as Director of the Institute of Physical Chemistry. His research focuses on energy and environmental catalysis, particularly polyoxometalate-based photocatalytic and electrocatalytic systems.