The Photocatalysed Removal of Hg II from Aqueous Solution

2 The photocatalysed removal of Hg(II) from aqueous solution The electrons promoted from the catalyst s valence band to its conduction band, when a suspension is uv-irradiated, will reduce Hg in solution to Hg which will deposit on the catalyst particles. 

3 TIk photocatalysed removal of ions from aqueous solution 

Cd(II) ions are more difficult to reduce than Hg(II). For their photocatalysed reduction, purging the suspension with nitrogen, removes oxygen which would compete with Cd ions for the photopromoted electrons. In addition, a hole scavenger e.g. methanol will minimise holeelectron recombination which would reduce the efficiency of the process. 

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