Photoelectrochemical properties and growth mechanism of varied ZnO nanostructures

Abstract

Herein, varied ZnO nanostructures have been fabricated and the mechanism of their transformation has been discussed. The morphology and the structure of the obtained ZnO nanostructures have been investigated. Moreover, the varied ZnO nanostructures were applied for photoelectrochemical (PEC) water splitting. The characterization suggests that the varied ZnO nanostructures exhibit a hexagonal wurtzite structure. On changing the standing time of the samples immersed in a growth solution, different morphologies of ZnO nanostructures can be attained, which present different PEC performances. Among these, ZnO nanotubes achieved a superior photocurrent of 0.49 mA cm⁻² at 1.2 V (vs. RHE). This excellent PEC performance can be attributed to the enhancement of light absorption intensity and the increased light refraction times, which implies that tubular structures are suitable for PEC water splitting.