Human health has already been significantly influenced by rising atmospheric CO 2 and declining O 2 levels posing critical challenges for environmental sustainability and life-support technologies. One solution to this problem is to develop photocatalytic material systems capable of capturing sufficient amounts of CO 2 for its visible light conversion to O 2 from water. The hypothesis of this study is that high surface area, porous, nanomaterial systems will capture enough CO 2 from water for its conversion to O 2 using visible light. Due to their high surface area and high porosity, here, a metal—organic framework (MOF-210) is expected to adsorb ample CO 2 and release large quantities of O 2 after combination with bismuth vanadate (BiVO 4 ) nanoparticles and photocatalysis. To test this, BiVO 4 nanoparticles were precipitated onto MOF-210, and the resulting composites were dispersed in water. Different concentrations of MOF-210 and water were tested. They were then exposed to visible light, and the initial and final CO 2 and O 2 levels were measured using CO 2 sensors and pH test strips. For comparison, the MOF-210 higher oxygen-containing BiVO 4 nanosystem was evaluated against a lower surface area oxygen-containing, non-porous, BiVO 4 -titanium dioxide (TiO 2 ) nanosystem. Materials were characterized and confirmed for size (using Scanning Electron Microscopy and Dynamic Light Scattering) and chemistry (using Energy Dispersive Chemistry). Experimental results showed that the high surface area, highly porous, MOF-210 did indeed adsorb sufficient CO 2 and when combined with BiVO 4 nanoparticles formed sufficient amounts of O 2 . The control lower surface area, non-porous, TiO 2 nanoparticle system did not generate sufficient O 2 . These findings confirm that the high surface area, highly porous MOF–BiVO 4 nanocomposites can indeed adsorb and convert sufficient CO 2 into useful O 2 highlighting the potential of MOF-based photocatalysts as dual-function materials for mitigating greenhouse gases and regenerating oxygen, with broader implications for climate change remediation and closed-loop life support in space exploration necessary to improve human health.
Doss et al. (Mon,) studied this question.