Effect of the Seed Layer on the Growth and Charge Transfer Behavior of ZnSnO Nanorods in Photoelectrochemical Water Splitting.

The growth of ZnSnO nanorods on two differently prepared ZnO seed layers is demonstrated using a hydrothermal approach. The ZnO seed layers are prepared using dip-coating and electrodeposition techniques. The grown ZnSnO nanorods are in the cubic phase. However, the different seed layers result in alternation in the diameter of grown ZnSnO nanorods. The photocurrent of ZnSnO nanorods grown on an electrodeposited ZnO seed layer is ∼4.5 times larger than that of ZnSnO grown on a dip-coated ZnO seed layer. The Nyquist plots of ZnSnO nanorods on the electrodeposited ZnO seed layer result in a lower charge transfer resistance ( = 37.7 Ω) and a lower bulk resistance ( = 64 kΩ), improving the charge transport properties. The change in diameter of ZnSnO nanorods significantly alters the charge transfer behavior. The calculated charge injection efficiency did not exhibit a significant change. However, there was a 1.6-fold enhancement observed in the charge separation efficiency for ZnSnO when grown on an electrodeposited seed layer.