Role of W‐Rich CuWO <sub>4</sub> and Doped Zn‐CuWO <sub>4</sub> Ceramics and Its Improved Photoelectrochemical Cell Performances Synthesized by Solid State Reaction Method
Venkatachalapathy Balasubramanian, S. Kannan, N. Thangaraj, G. Sivakumar, K. Mohanraj
Abstract
Abstract Triclinic CuWO 4 and Zn doped CuWO 4 nanocomposites have been synthesized by the solid state reaction method to evaluate the Photoelectrochemical (PEC) performance of the photoelectrodes. The existence of WO 3 along with CuWO 4 is affirmed by the XRD, XPS spectra and HRTEM images. PEC measurements showed that the generated photocurrent is found to be maximum of about 8.94 mA/cm 2 for Zn doped CuWO 4 whereas it is 2.63 mA/cm 2 for bare CuWO 4 electrode measured at 0.1 M of Na 2 SO 4 acts as a suitable electrolyte under the illumination. The carrier density (N d ) of the nanocomposites is determined by Mott‐Schottky plot that has n‐type conductivity for both the samples. The negative flat band potential of −0.52 V for Zn doped CuWO 4 might be attributed to decrease in depletion width. Zn doped CuWO 4 shows higher power conversion efficiency of about 3.95%. The solution resistance and charge transfer resistance of both the photoelectrodes were calculated using Nyquist plot and it is lower for Zn‐CuWO 4 which indicates better conductivity and electron transfer rate.