Photocurrent enhancement via trapping of photogenerated electrons of TiO₂ particles

The photocurrente derived from TiO₂ suspensions are enhanced when reducible species such as Cu²⁺ and Fe³⁺ are added to cells containing these suspensions. This process is proposed to occur via trapping of photogenerated electrons in the TiO₂ by these solution species, thereby reducing the extent of deleterious electron-hole recombination. The ability of platinum deposits on TiO₂ particles to participate in electron trapping and enhance photocurrent via formation of Pt-H species was demonstrated by electrochemical detection of adsorbed H on irradiated Pt/TiO₂.