Efficient carbon-based electrocatalyst derived from biomass for hydrogen peroxide generation

Transforming litchi waste into valuable metal-free ORR catalysts for generation of H2O2. [Display omitted] •The bio-mass waste of litchi shell is transformed into ORR catalyst for generation of H2O2.•The study provides a cheap precursor for noble-metal free catalyst.•The study presents a facile way to treat the litchi shell waste. Abundantly available natural source of litchi shell was investigated as the precursor for a P-doped carbon-based electrocatalyst toward oxygen reduction reaction (ORR) to generate hydrogen peroxide. The obtained carbon with a BET specific surface area of 693 m2 g−1 exhibited hierarchical porous structures with micropores and macropores derived from the special structure of the litchi shell. The hierarchical porous structure is beneficial for a high catalytic activity. An onset and half wave potential of ∼0.98 and ∼0.80 VRHE were obtained in the electrolyte of 0.1 M KOH solution, respectively. More importantly, the high H2O2-efficiency (∼60 %) can be achieved with the porous carbon. The present work provides a new pathway to fabricate an efficient metal-free electrocatalyst of heteroatom-doped carbon from biomass while addressing the disposal issue of litchi shell, making a contribution to the biomass utilization, demonstrating the potential of the present work in sustainable and green aspects.