At present, the preparation of highly active, long-term durable, and low cost electro-catalysts toward oxygen evolution reaction is still a challenge for energy conversion and storage. This work reports CoS1.097 embedded in flower-like biomass derived from red blood cells (RBCs) nanocatalyst, was synthesized via a one-step, hydrothermal method. Compared to pure CoS1.097 microspheres, the generated flower-like CoS1.097-biomass (CoS1.097-B) nanosheets exhibits enhanced OER electrocatalytic activity with a onset potential of 1.43 V (vs. RHE), an overpotential of 260 mV at the current density of 10 mA cm(-2), and a low Tafel slope of 83 mV dec(-1). Moreover, the CoS1.097-B displays good OER stability with little decrease after 400 cycles. Our work provides a reference for designing catalysts with high activity and good stability using biomass under mild conditions. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.