Nitrogen, sulfur, and oxygen tri-doped carbon nanosheets (N, S, O-CNs) were prepared by a modified in-situ g-C3N4 template method with a plant-waste, rice straw, as the carbon precursor. The N, S, O-CNs could worked as efficient electrocatalysts for oxygen reduction reaction (ORR), oxygen evolution reaction (OER), and hydrogen evolution reaction (HER). Significantly, the introduced S element can particularly activate the electron transfer and accelerate reaction kinetics for HER, while the N/O dopants can efficiently promote the ORR and OER. As a result, the N, S, O-CNs exhibited excellent performance with favorable ki-netics and decent durability as a multifunctional ORR, OER and HER catalyst. Moreover, the rechargeable liquid/solid Zn-air battery and water splitting device showed superior per-formance by assembling this N, S, O-CNs catalyst. This work paves a universal avenue towards further development of plant-waste derived carbon materials with heteroatom dopants as the highly efficient electrocatalysts in energy devices.& COPY; 2023 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.