“…3 The OH* and O* occupy the active sites spontaneously when DG intersects the x-axis (DG ¼ 0). For NSS, OH* and O* could be generated at potentials above 1.70 and 1.62 V RHE , whereas at least 1.65 and 1.86 V RHE were required for NSS/SiO This work considered the potential parallel pathways of O 2 * formation, i.e., a binuclear mechanism (eqn ( 8)-( 10)) 3,5,24 and a four-step associative mechanism (consecutive equations of eqn ( 8), ( 9), ( 12) and ( 13)). 10,55,56 Regarding the latter pathway, a free-energy diagram (Fig.…”