1. Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, U.K.
2. School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang 453007, China
3. Imaging Facility, University of Bath, Bath BA2 7AY, U.K.
4. HarwellXPS, Research Complex at Harwell, STFC Rutherford Appleton Laboratory, Harwell Campus, Didcot OX11 0FA, U.K.
5. Department of Chemistry, University College London, London WC1H 0AJ, U.K.
6. Integrated Graphene Ltd., Euro House, Wellgreen Place, Stirling FK8 2DJ, U.K.