Plasmonic Au nanoparticles sensitized ZnO/CuO heterostructure for efficient photoelectrochemical water splitting
Pratibha Shinde, Ashvini Punde, Shruti Shah, Ashish Waghmare, Yogesh Hase, Bharat Bade, Vidya Doiphode, Somnath Ladhane, Swati Rahane, Dhanashri Kale, Sachin R. Rondiya, Mohit Prasad, Sandesh Jadkar
Abstract
Hydrogen production via photoelectrochemical water splitting is a promising route to convert solar energy into chemical fuel, reducing energy crises and boosting environmental health. Here, we report the fabrication of ternary ZnO/CuO/Au heterostructures by electrodeposition and chemical bath deposition methods . The heterojunction formed can enhance the optical absorption , and photogenerated electrons and holes can efficiently separate due to the built-in electric field, which reduces recombination losses . Au plasmons incorporated in ZnO/CuO heterojunction enhance the optical absorption and promote fast free charge carrier transport at the interface through the surface plasmon resonance (SPR) effect. The ZnO/CuO/Au photoanode exhibits a photocurrent density of 1.08 mA/cm 2 at 1.6 V Vs RHE , two times higher than pristine ZnO . The ZnO/CuO/Au photoanode exhibits the lowest charge transfer resistance of 600 Ω from electrochemical impedance spectra(EIS). The Bode plot revealed that the most extended lifetime of 8.69 μs is observed for ZnO/CuO/Au photoanode, which is larger than pristine ZnO. The synthesized thin films showed good stability and reusability for the photooxidation of water.