Effect of the Seed Layer on the Growth and Charge Transfer Behavior of Zn2SnO4 Nanorods in Photoelectrochemical Water Splitting

The growth of Zn2SnO4 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 Zn2SnO4 nanorods are in the cubic phase. However, the different seed layers result in alternation in the diameter of grown Zn2SnO4 nanorods. The photocurrent of Zn2SnO4 nanorods grown on an electrodeposited ZnO seed layer is ∼4.5 times larger than that of Zn2SnO4 grown on a dip-coated ZnO seed layer. The Nyquist plots of Zn2SnO4 nanorods on the electrodeposited ZnO seed layer result in a lower charge transfer resistance (Rct = 37.7 Ω) and a lower bulk resistance (Rbulk = 64 kΩ), improving the charge transport properties. The change in diameter of Zn2SnO4 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 Zn2SnO4 when grown on an electrodeposited seed layer.