In term of properties of both 2D dimensional material, Do you think novel 2D material MXene has high potential for environmental solution comparing to Graphene?
MXenes are not one material, but an entire group of compounds. Of course you will find MXenes with properties more suitable for specific applications in comparison with graphene, but of course there is a reason why graphene has the "hype train" on its side since it quite uniquely combines mechanical and electronic properties and at least I haven't seen reports on relativistic properties in MXenes comparable to graphene.
As metioned by Weippert, mxenes refer to a large group of materials of 2D nitrides or carbides. So, it may not be fair to compare mxene with graphene for a specific application. Especially, the excellent properties of graphene can only be expected on single-layer graphene (the real graphene), but multilayered accordion-shaped mxenes are often used in many cases. For environmental application, mxenes are probable more promising than graphene, but it depends.
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It depends on the preparation process and on which part you are using a particle to cure an environmental problem. You can modify the graphene with various metals to enhance its activity and the same is applicable for mxenes also. So, I think a broad comparison on these is not possible but one can compare on the basis of the doping or engrafting materials onto these (if same doping is done).