Metal-free N–S- and N–P-doped nanocarbon (SCNP and PCNP) electrocatalysts prepared through sustainable microwaveassisted synthesis using hemigraphis alternata plant leaves. The prepared heteroatom-doped nanocarbon materials are active catalysts for the two-electron oxygen reduction reaction (ORR) to produce 65–70% of hydrogen peroxide. As evidenced from the XPS, most proportion of the doped heteroatoms contain the oxygen functional groups in the nanocarbons. These attributes are the critical factors to see the selective two-electron transfer ORR for the PCNP and SCNP. This approach shed light on the critical role of dual heteroatoms doping and the oxygen functionalities in nanocarbon towards the selectivity of ORR. We believe that this method would allow the preparation of heteroatom that contains oxygen functionalities. Our work paves a sustainable way of preparation of nanocarbon based ORR catalysts that are only selective for two-electron transfer process.

Dual heteroatoms doped nanocarbons: electrocatalysts for hydrogen peroxide synthesis
    Abstract
        Graphical abstract
    1 Introduction
    2 Experimental section
        2.1 Synthesis of SCNP and PCNP
        2.2 Characterization and electrochemical measurements
    3 Results and discussion
        3.1 Electrocatalytic activity of carbon NPs towards oxygen reduction reaction
    4 Conclusions
    Acknowledgements 
    References

• K. Sudhakara Prasad(Nanomaterials Research Laboratory (NMRL), Smart Materials and Devices, Yenepoya Research Centre, Yenepoya (Deemed to be University), Deralakatte, Mangalore 575 018, India, Centre for Nutritional Studies, Yenepoya (Deemed to be University), Deralakatte, Mangalore 575 018, India) Corresponding author
• M. H. Naveen(Department of Chemistry, Institute of BioPhysio Sensor Technology (IBST), Pusan National University, Pusan 609 735, South Korea, Present Address: KAUST Catalysis Center (KCC), King Abdullah University of Science and Technology (KAUST), 23955‑6900 Thuwal, Saudi Arabia)
• H. Manisha(Nanomaterials Research Laboratory (NMRL), Smart Materials and Devices, Yenepoya Research Centre, Yenepoya (Deemed to be University), Deralakatte, Mangalore 575 018, India)
• A. B. Suriani(Department of Physics, Faculty of Science and Mathematics, Universiti Pendidikan Sultan Idris, 35900 Tg. Malim, Perak, Malaysia)
• T. G. Satheesh Babu(Department of Sciences, Amrita Vishwa Vidyapeetham, Amrita School of Engineering, Amritanagar, Coimbatore 641112, India)
• Yoon‑Bo Shim(Department of Chemistry, Institute of BioPhysio Sensor Technology (IBST), Pusan National University, Pusan 609 735, South Korea)