Properties of graphene change in humid conditions

Researchers from Queen Mary University of London have shown that graphene exhibits very different properties in humid conditions. Their study shows that in bi-layer graphene, water seeps between the layers in a humid environment. The properties of graphene significantly depend on how these carbon layers interact with each other and when water enters in between it can modify the interaction. The results of this study could impact how graphene can be used in real-life applications.

The researchers found the water forms an atomically thin layer at 22% relative humidity and separates graphene layers at over 50% relative humidity. This suggests that layered graphene could exhibit very different properties in a humid place, compared to a dry place.

Lead author Dr Yiwei Sun, said: The critical points, 22% and 50% relative humidity, are very common conditions in daily life and these points can be easily crossed. Hence, many of the extraordinary properties of graphene could be modified by water in between graphene layers.

He added: Some graphene-based devices may function to their full capability in dry places while others may do so in humid places. We suggest all experiments on 2D materials should in future record the relative humidity.

The researchers suggest humidity is also likely to have an impact on other layered materials such as boron nitride (sheets made of boron and nitrogen) and Molybdenum disulphide (sheets made of molybdenum and sulphur).

Posted: Jan 22,2019 by Roni Peleg