Correction to: npj 2D Materials and Applications https://doi.org/10.1038/s41699-021-00255-8, published online 23 August 2021

The original version of this Article contained an error in the second sentence of the Introduction section, which incorrectly stated “…; coke is produced by heating slurry oils and decant oils from refinery units such as Fluid Catalytic Crackers”. The correct version replaces this sentence with “…; coke is produced by heating resids or slurry oils from refinery units such as Fluid Catalytic Crackers”.

This has been corrected in both the PDF and HTML versions of the Article.