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Published online: 6 August 2008 | doi:10.1038/nchina.2008.184

Artificial photosynthesis: Stored in a tube

Tim Reid

Introduction

© (2008) Wiley Interscience

The ability to mimic photosynthesis in the lab could revolutionize the production of hydrogen fuel, and act as a strong weapon against rising levels of carbon dioxide in the atmosphere. Now a supermolecule made by Xianfu Zhang at Hebei Normal University of Science and Technology in Qinhuangdao and co-workers¹ could provide an important step in the process — separating and storing multiple electrons.

Artificial photosynthesis requires molecules that respond to light by releasing or storing several electrons at a time. Most experiments have only succeeded in transferring one electron per molecule.

Zhang and co-workers decided to exploit the storage capacity of a carbon nanotube, which can accept one electron for every 32 carbon atoms in its shell. They created a supermolecule by binding several molecules of phthalocyanine — a dye that releases an electron when light is absorbed — onto the surface of a single-walled nanotube (see image).

The nanotube effectively acts as an electrical capacitor, catching and storing about a quarter of the electrons released by the phthalocyanine. The electrons could potentially be used for solar electricity or to fuel high-energy reactions, such as the synthesis of carbohydrates, which also removes carbon dioxide from the atmosphere.

The authors of this work are from:
Chemistry Department, Hebei Normal University of Science and Technology, Qinhuangdao, China; Chemistry Department, Tsinghua University, Beijing, China.

Reference

1. Zhang, X. F., Cui, X., Liu, Q. & Zhang, F. Multiple-charge separation in nanoscale artificial photosynthetic models. ChemPhysChem doi: 10.1002/cphc.200800191 (2008). | Article |