Abstract:A series of chromium-doped jarosite nanospheres KFe3-xCrx(SO4)2(OH)6) with diverse microstructures were prepared by hydrothermal synthesis method. Microstructure and physicochemical properties of catalyst were investigated with the aid of XRD, SEM, FT-IR and Raman, and electrocatalytic oxygen evolution performance (OER) of samples were measured through electrochemical workstation. The results show that Cr3+ replaces part of Fe3+, and with the increase of the molar ratio of n(Fe3+/Cr3+), morphology of jarosite transforms from irregular nanoparticles to uniformly sized nanospheres. When n(Fe3+/Cr3+)=2, the synthesized KFe2Cr1(SO4)2(OH)6 is a nano-microsphere with smooth surface and diameter is about 450~550 nm. When the current density is 10 mA/cm2, the over potential is 362 mV and the Tafel slope is 73 mV dec-1, meanwhile, the voltage does not change significantly after 20 h of constant potential test and basically stabilized, which indicates that KFe2Cr1(SO4)2(OH)6 microsphere exhibits excellent OER catalytic performance and stability, and providing a new direction for application of jarosite.