Role of W-Rich CuWO4and Doped Zn-CuWO4Ceramics and Its Improved Photoelectrochemical Cell Performances Synthesized by Solid State Reaction Method

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.