Electrochemical Behavior of S and C Mono-Doped Sodium Tantalate Photocatalysts


Sodium tantalate powder was synthesized and doped with suitable anions using a low-temperature hydrothermal process. The prepared samples were investigated for photocatalytic and electrochemical behavior using various characterization techniques. The crystal structure, stretching frequencies, and surface morphology were studied using X-ray diffraction spectroscopy (XRD), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM), respectively. The electrochemical performances of the samples were studied by cyclic voltammetry (CV), galvanostatic charge-discharge (GCD), and electrochemical impedance spectroscopy (EIS) analysis. Kinetics of hydrogen evolution (HER) and oxygen evolution (OER) reactions in a basic electrolyte were also investigated. From the above characterization techniques, it has been revealed that NaTaO3 (or, NT), c-NaTaO3 (or, cNT), and s-NaTaO3 (or, sNT) have a cubic crystal structure in the perovskite phase and possess direct band gaps of energies 3.9 eV, 3.8 eV, and 3.7 eV, respectively. The average crystallite size of NT, cNT, and sNT is calculated as 15 nm, 12 nm, and 20 nm, respectively. sNT has higher capacitive properties than NT and cNT, but it cannot be considered a typical supercapacitor electrode material. However, all the samples have shown optimal performance in hydrogen and oxygen evolution processes.

Publication Title

Journal of Electronic Materials