Synthesis of Ag and N doped potassium tantalate perovskite nanocubes for enhanced photocatalytic hydrogen evolution

•Potassium tantalate photo-catalyst with silver and nitrogen dopant was prepared by solvothermal method.•Silver doped photo-catalyst generates 2.7 times hydrogen than nitrogen doped KTaO3.•Silver doped potassium tantalate shows retained photocatalytic activity of 91% even after three days. Potassium tantalate (KTaO3) was synthesized by solvothermal process and an effort has been made with the addition of Ag and N as dopants and accessed for hydrogen evolution measurements. The structural aspect and the average crystallite size were confirmed from X-ray diffraction analysis. The particle size and cubic morphology were proved from FESEM and its compositions were confirmed by Energy Dispersive Spectroscopy. The band gap and the band edge potential were evaluated from the UV–visible spectral studies. Photocatalytic H2 evolution for the undoped, Ag and N-doped KTaO3 under UV light are 375, 2072 and 752 µmolh−1g−1. The highest rate of H2 production was achieved for Ag doped KTaO3 using 450 W Xe-Hg UV lamp without co-catalyst is not yet attained. Further the reliability test of the optimized photocatalyst showed that 91% of the photocatalytic activity was retained even after three days.