Exploring cheap and efficient oxygen evolution reaction (OER) catalysts is extremely vital for the commercial application of advanced energy storage and conversion systems. Herein, a self-supporting Co3S4/ S-doped reduced graphene oxide ( Co3S4/S-rGO) film catalyst is successfully prepared by a blade coating coupled with high-temperature annealing strategy, and its morphology, structure and composition are measured and analyzed. It is substantiated that the as-synthesized Co3S4/ S-rGO film possesses unique self-supporting structure, and is composed of uniformly dispersed Co3S4 nanoparticles and highly conductive S-rGO, which benefit the exposure of catalytic sites and electron transfer. By reason of the synergistic effect of the two individual components, the self-supporting Co3S4/ S-rGO film catalyst displays outstanding catalytic performance towards OER. As a consequence, the Co3S4/ S-rGO film catalyst delivers an overpotential of 341 mV at 10 mA cm-2, and the current attenuation rate is only 2.6% after continuous operation for 4 h, verifying excellent catalytic activity and durability. Clearly, our results offers a good example for the construction of high-performance self-supporting carbon-based composite film catalysts for critical electrocatalytic reactions.

Preparation of self-supporting Co3S4S-rGO film catalyst for efficient oxygen evolution reaction
    Abstract
    1 Introduction
    2 Experimental
        2.1 Sample preparation
    3 Results and discussion
    4 Conclusion
    5 Supplementary Information
    Anchor 9
    Acknowledgements 
    References

• Liang Chen(Key Laboratory of Hunan Province for Advanced Carbon‑Based Functional Materials, School of Chemistry and Chemical Engineering, Hunan Institute of Science and Technology, Yueyang 414006, Hunan, China)
• Liying Hu(Key Laboratory of Hunan Province for Advanced Carbon‑Based Functional Materials, School of Chemistry and Chemical Engineering, Hunan Institute of Science and Technology, Yueyang 414006, Hunan, China)
• Chenxi Xu(Key Laboratory of Hunan Province for Advanced Carbon‑Based Functional Materials, School of Chemistry and Chemical Engineering, Hunan Institute of Science and Technology, Yueyang 414006, Hunan, China, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, Hunan, China)
• Lanyun Yang(Key Laboratory of Hunan Province for Advanced Carbon‑Based Functional Materials, School of Chemistry and Chemical Engineering, Hunan Institute of Science and Technology, Yueyang 414006, Hunan, China)
• Wei Wang(Key Laboratory of Hunan Province for Advanced Carbon‑Based Functional Materials, School of Chemistry and Chemical Engineering, Hunan Institute of Science and Technology, Yueyang 414006, Hunan, China)
• Junlin Huang(Key Laboratory of Hunan Province for Advanced Carbon‑Based Functional Materials, School of Chemistry and Chemical Engineering, Hunan Institute of Science and Technology, Yueyang 414006, Hunan, China)
• Minjie Zhou(Key Laboratory of Hunan Province for Advanced Carbon‑Based Functional Materials, School of Chemistry and Chemical Engineering, Hunan Institute of Science and Technology, Yueyang 414006, Hunan, China)
• Zhaohui Hou(Key Laboratory of Hunan Province for Advanced Carbon‑Based Functional Materials, School of Chemistry and Chemical Engineering, Hunan Institute of Science and Technology, Yueyang 414006, Hunan, China)