Photocatalysts having the same bandgap but behave differently because the position of conduction band minimum (CBM) and valence band maximum (VBM) determines their redox ability. In previous reports, the Mott-Schottky technique is used to determine the CB position. For the Mott-Schottky technique, the apparent capacitance is measured as a function of potential and by eqn. ( ) . The CBM can be determined by extrapolation of C = 0. The obtained CBM value is versus the reference electrode and conductive media.