Abstract:

The artificial photosynthesis system can use solar energy to convert carbon dioxide into high value-added chemical products, which can effectively solve the energy and environmental problems faced by mankind, and has great development prospects. However, artificial photosynthesis systems face major challenges such as poor product selectivity, high overpotential, and low solar energy utilization. Here we present a hybrid microbial-photoelectrochemical system comprised of a monolithic photoanode, which is assembled by attaching a silicon cell at the reverse side of a TiO₂ nanorod array for water oxidation, and a biocathode that is capable of reducing CO₂ to CH₄. The hybrid system shows an excellent CH₄ production rate of (10.7±0.2) L·d^-1·m^-2, around 13 times higher than that of previous studies, and achieved a highly selective CO₂ reduction to CH₄ with a Faradaic efficiency up to 98.5%±2.1%. This work proposes an effective approach for the generation of valuable products using artificial photosynthesis.

Key words: artificial photosynthesis, monolithic photoanode, biocatalysis, CO₂ reduction

摘要：

人工光合作用系统可以利用太阳能将二氧化碳转化为高附加值的化学产品，能够有效地解决人类面临的能源与环境问题，极具发展前景。然而，人工光合作用系统面临产物选择性差、过电位高、太阳能利用率低等重大挑战。本文提出了一种新型微生物/光电化学耦合人工光合作用系统，该系统由固碳产甲烷微生物阴极和复合光阳极组成，其中复合光阳极由TiO₂电极与硅太阳能电池串联组成。该耦合系统在仅输入太阳能且不施加外部偏压的条件下，可实现化学燃料甲烷的产生。甲烷产量高达（10.7±0.2） L·d^-1·m^-2，相比已有研究高出13倍，同时该耦合系统固碳产甲烷的法拉第效率高达98.5%±2.1%，远高于传统的人工光合作用系统。该新型人工光合作用系统的提出，为制取具有高附加值的化学产品和发展可再生能源提供了新的思路。

关键词: 人工光合作用, 复合光阳极, 生物催化, CO₂还原