Simple and Low-Cost Synthesis of Ba-Doped CuO Thin Films for Highly Efficient Solar Generation of Hydrogen
Ashour M. Ahmed, Esraa Mohamed Abdalla, Mohamed Shaban
Abstract
Hydrogen gas is an eco-friendly energy source that can be directly converted to electricity using fuel cells. In this work, CuO and Ba-doped CuO thin films were prepared on glass substrates using a simple successive ionic layer adsorption and reaction (SILAR) method for hydrogen production. For pure and doped films, the (−111) plane was the preferred crystallographic orientation. The bandgap of the pure CuO film was tuned from 1.63 to 1.87 eV after incorporating 6% Ba. The average nanoparticle size of the pure CuO film was reduced from ∼195 to ∼100 nm and then to 90 nm as the Ba doping ratio was increased from 2 to 4%. The pure and doped CuO films were composed of a random distribution of nanoparticles in an irregular form, as demonstrated by scanning electron microscopy (SEM). Energy-dispersive X-ray spectroscopy (EDX) patterns demonstrated the high purity of the deposited films and the rise of the Ba atomic % from 0.21 to 0.82 by increasing the doping level to 6%. The 2% Ba-doped CuO films showed a high photocatalytic performance as a photoelectrode for efficient hydrogen generation. The Ba-doped CuO film displayed the best performance for the water-splitting reaction (photocurrent density J = 17 mA/cm2) with long-term stability against photocorrosion. The conversion efficiencies incident photon-to-current efficiency (IPCE) and applied bias photon-to-current efficiency (ABPE) were 39.6% at 440 nm and 5.75% at 0.41 V, respectively. Consequently, our work introduced an efficient and cost-effective photocathodic material for practical and industrial hydrogen production.