Superior photoelectrodes of nanostructured Mo-doped CuO thin film for green hydrogen generation from photoelectrochemical water-splitting

Abstract

Green hydrogen has an audible echo in the clean energy field. In this piece of work, pure and Mo-doped CuO thin films were deposited at different substrate temperatures on the Indium Tin Oxide (ITO) by the DC/RF sputtering technique. The prepared samples were utilized to generate hydrogen gas within the photoelectrochemical water-splitting mechanism. Crystallographic planes (−111), and (200) were the preferred orientations for pure and Mo-doped CuO thin films. Moreover, the average crystallite size was doubled by Mo doping reaching 25.8 nm. FE-SEM microscopic image exhibits that the pure and Mo–CuO thin films have a regular distribution with a small size. The optical band gap has rosed by doping from 1.8 eV to 2.05 eV. Then, it increased to 2.3 eV and 2.4 eV at temperatures of 100 °C and 200 °C respectively. Pure and Mo–CuO thin films were applied as photocathodes for hydrogen generation with water water-splitting technique. The photoelectrochemical application revealed a photocurrent density of ∼2.25 mA/cm2 for Mo-doped CuO photoelectrode at room temperature. This optimum photoelectrode was studied for stability and electrochemical impedance. In addition, the incident photon to current efficiency (IPCE%) was 4.47 % at 500 nm. The applied bias photon to current conversion efficiency (ABPE%) was 4.25 % at −0.38V. As a result of the above, pure and Mo-doped CuO photoelectrodes are low-cost thin films and have a high-efficiency performance for green hydrogen generation industrially.