* Corresponding authors

^a Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, UK
E-mail: f.marken@bath.ac.uk

^b Department of Mechanical Engineering, University of Bath, Claverton Down, Bath BA2 7AY, UK

^c Department of Architecture & Civil Engineering, University of Bath, Claverton Down, Bath BA2 7AY, UK

^d EaStCHEM School of Chemistry, University of Edinburgh, Joseph Black Building, David Brewster Road, Edinburgh, Scotland EH9 3JF, UK

^e Department of Chemistry, Swansea University, College of Science, Grove Building, Singleton Park, Swansea SA2 8PP, UK

^f University of Bath, Materials & Chemical Characterisation Facility, MC2, UK

^g HarwellXPS, Research Complex at Harwell, STFC Rutherford Appleton Laboratory, Harwell Campus, Didcot, UK

^h Stephenson Institute for Renewable Energy, Department of Chemistry, University of Liverpool, Liverpool L69 7ZF, UK

ⁱ The Faraday Institution, Harwell Campus, Didcot, UK

^j Schlumberger Cambridge Research, High Cross, Madingley Road, Cambridge CB3 0EL, UK

^k Central Laser Facility, Research Complex at Harwell, STFC Rutherford Appleton Laboratory, Harwell Campus, Didcot OX11 OQX, UK