Thirumany Sritharan
Nanyang Technological University, Singapore
Title: Improvements and scale up of BiVO4 photoanode for water splitting in photoectrochemical cells
Biography
Biography: Thirumany Sritharan
Abstract
The monoclinic scheelite BiVO4 is recognized as one of the promising candidate materials for photoanode because of its 9.1% theoretical solar-to-hydrogen efficiency. While signifi cant research effort has been devoted to improving the photoelectrochemical cell performance of this material, they have mainly been in small anode areas. This talk will give the methodologies employed to produce a scaled-up 5x5 cm2 photoanode and give results of its performance in a large photoelectrochemical cell to split water. Multiple modifi cations were made, by systematic experimental evaluations, to enhance the performance of the anode. These are: use of an under layer, an over layer of co-catalyst, and doping the BiVO4 with Mo. These will be described. An adverse effect of area was noted in our studies which we call the “areal effect”. The photocurrent density steadily decreased with increase of illumination area. Evidence to specifically verify the areal effect were obtained experimentally and will be discussed. This is the first documented evidence for this effect. Understanding the reasons for the areal effect is indispensable for the development of large scale PEC devices for water splitting. Preliminary information on the stability of the large area anode in the electrolyte will also be shown and discussed.