“…This treatment is not popular. In fact, many models for the lowly doped semiconductor electrodes supposed that the capacitance of the semiconductor side of the interface was much smaller than that of the Helmholtz layer and most applied potential dropped in the depletion layer. , Moreover, that time-dependent accumulation of surface charge at the surface may affect, in turn, the redistribution of potential over the depletion and Helmholtz layer and couple to the interfacial kinetics, while this effect is not taken into account for the most of PEC reactions at the semiconductor electrode including TiO 2 . In addition, during the early stages of the studies of semiconductor surface processes, the presence of surface states at the interface is commonly believed to be important in dictating the charge-transfer process. 12a,− For example, to account for a high current efficiency (almost 100%) for O 2 evolution during photoelectrolysis of water, a contribution of surface states in charge transfer has been proposed 12g.…”