Floatable artificial leaf to couple oxygen-tolerant CO2 conversion with water purification
Zhiyong Zhang, Yang Wang, Yangen Xie, Toru Tsukamoto, Qi Zhao, Qing Huang, Xingmiao Huang, Boyang Zhang, Wenjing Song, Chuncheng Chen, Hua Sheng, Jincai Zhao
Abstract
To enable open environment application of artificial photosynthesis, the direct utilization of environmental CO2 via an oxygen-tolerant reductive procedure is necessary. Herein, we introduce an in situ growth strategy for fabricating two-dimensional heterojunctions between indium porphyrin metal-organic framework (In-MOF) and single-layer graphene oxide (GO). Upon illumination, the In-MOF/GO heterostructure facilitates a tandem CO2 capture and photocatalytic reduction on its hydroxylated In-node, prioritizing the reduction of dilute CO2 even in the presence of air-level O2. The In-MOF/GO heterostructure photocatalyst is integrated with a porous polytetrafluoroethylene (PTFE) membrane to construct a floatable artificial leaf. Through a triphase photocatalytic reaction, the floatable artificial leaf can remove aqueous contaminants from real water while efficiently reducing CO2 at low concentrations (10%, approximately the CO2 concentration in combustion flue gases) upon air-level O2. This study provides a scalable approach for the construction of photocatalytic devices for CO2 conversion in open environments. Achieving artificial photosynthesis in open environments is highly challenging. Here, the authors present a composite of indium metal-organic framework and graphene oxide that efficiently reduces low-concentration CO2 containing air-level O2 while effectively removing contaminants from real water.