Photocatalysed Reduction of Ag I by ZnO

Weigh out accurately 0.20 g purest ZnO. Suspend in 20 cm of saturated silver sulphate solution. Stirring the suspension magnetically, irradiate in a reproducible position under a low pressure mercury lamp for 30 minutes. Filter through a prepared sintered crucible, wash till the filtrate is Ag -free. Heat at 100°C for one hour and reweigh. 

Repeat using 0.20 g of either anatase or rutile. In a repeat experiment, instead of heating the product, add 20 volume H2O2 to achieve maximum colour change. 

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