Does Sansevieria trifasciata really absorb Carbon Dioxide at night?
This is an interesting topic!  

Crassulacean acid metabolism is a second CO₂ fixation pathway where CO₂ is absorbed at night.  The CO₂ is fixed into maleic acid HOOC-CH₂CH(OH)-COOH which stores some of the CO₂ in the form of carboxyl groups.  During the day carboxylases release the CO₂ for fixation during the day.  

This is an adaptation where the stomata open at night to take in the CO₂ and are closed during the day - the plants sort of 'hold their breath'.  The energy for this process is derived for glycolysis which were stored during the day (nice detailed review here). 

The paper says that about 6% of plants (including Mother-in-Laws Tongue) do this and you can imagine with night breathing how closing the stomata during the day would really help with dehydration.  Its interesting to note that this is found in a wide variety of plants "CAM is found in five taxonomic classes, comprising monocots and dicots, encompassing 33 families and 328 genera".  That says that CAM is a pretty old development in plant evolution and not so expensive that it is easily lost.