Essential data in CSV format from our publication in Nature Materials (2020) entitled Linking in-situ charge accumulation to electronic structure in doped SrTiO3 reveals design principles for hydrogen evolving photocatalysts. by Benjamin Moss, Qian Wang, Keith T. Butler, Ricardo Grau-Crespo, Shababa Selim, Anna Regoutz , Takashi Hisatomi , Robert Godin, David J. Payne, Andreas Kafizas, Kazunari Domen, Ludmilla Steier* and James R. Durrant repository contains XPS data (shows raw EB folowed by EB after C 1s calibration to 284.8 eV. O 1s is provided with the VB data to faciliate core line separation analysis) DFT data (STO, Rh:STO and La,Rh:STO all have differnt VB minima due to the introduction of new states. Thus all have different 0K Ef positions DFT data was calibrated to the CB edge, the potential of which we calcualte to be unaffected by doping.) SEC data (was repeated twice with samples from two batches to make sure the effects observed was reproducable. For simplicity, only one set of SEC data is provided here. To get the sigmoidal plots shown normalise against 0 or -0.2 V RHE (i.e. divide everything else by the negative abs value at 590 nm at this potential)) TAS and PIA data.