Source: School of Chemistry
Edited by: Zheng Longfei, Wang Dongmei

Artificial photosynthesis is a straightforward and environmentally friendly way to convert solar energy into chemical energies. However, artificial photosynthesis in ambient conditions is much less efficient than the solar-to-biomass conversion (SBC) processes in nature. Photocatalytic water splitting and nitrogen fixation are frequently studied SCC systems. Nonetheless, both these systems are limited to gas atmospheres absent of O₂, because oxygen reduction presents a competitive reaction as it is thermodynamically preferred. Moreover, it is quite dangerous when the explosive products are mixed with the ubiquitous O₂ in air. Hence, special facilities and equipment are always required to ensure efficiency and safety in these two SCC systems.


Recently, a research team led by Professor Gangfeng Ouyang from School of Chemistry at Sun Yat-sen University successfully mimics the NADP-mediated photosynthetic processes in green plants by introducing redox moieties as the electron acceptors in the present conjugated polymeric photocatalyst. The current artificial process substantially promotes the charge carrier separation efficiency and the oxygen reduction efficiency, achieving a photosynthesis rate for converting Earth abundant water and oxygen in air into hydrogen peroxide as high as 909 μ·mol·g-1·h-1 and a solar-to-chemical conversion (SCC) efficiency up to 0.26%. The SCC efficiency is more than two times higher than the average SBC efficiency in nature (0.1%) and the highest value under ambient conditions. This study presents a strategy for efficient SCC in the future.

The research results have been published in Proceedings of National Academy of Sciences of the United States of America (PNAS) entitled “A solar-to-chemical conversion efficiency up to 0.26% achieved in ambient conditions”. The first author is Dr. Yu-Xin Ye, School of Chemistry, Sun Yat-sen University. Professor Gangfeng Ouyang is the corresponding author. This work was supported by the Key Program of National Natural Science Foundation of China, Guangdong Provincial Key R&D Programme, the NSF of Guangdong Province and the Fundamental Research Funds for the Central Universities.

Link to the paper: https://www.pnas.org/content/118/46/e2115666118