Enhanced photoelectrochemical hydrogen evolution by 2D nanoleaf structured CuO.

Copper oxide (CuO) is a p-type semiconductor material having versatile use in a wide number of applications. In this work, a CuO nanoleaf structure has been synthesized without any traces of Cu2O by a one-step facile method under mild refluxing conditions. The phase purity of the sample is confirmed by x-ray diffraction, x-ray photoelectron spectroscopy, and high resolution transmission electron microscopy. Photoelectrochemical performance has been evaluated by linear scan voltammetry, and transient photocurrent has been measured in the presence of a visible light source of 350 W. Transient photocurrent shows a high photocurrent density of −6.0 mA cm−2 [at −0.2 V vs reference hydrogen electrode (RHE)] in neutral pH. The enhancement of photocurrent density is due to the large space charge region potential, confirmed by a Mott–Schottky measurement. This large space charge region potential is responsible for the higher efficiency of electron–hole separation and a concurrent increase in the kinetics of the process. [ABSTRACT FROM AUTHOR]