Ultrasound-assisted transformation from waste biomass to efficient carbon-based metal-free pH-universal oxygen reduction reaction electrocatalysts

摘要: Abstract Efficient carbon-based nitrogen-doped electrocatalysts derived from waste biomass are regarded as a promising alternative to noble metal catalysts for oxygen reduction reaction (ORR), which is crucial fuel cell performance. Here, coconut palm leaves employed the carbon source and series of porous carbons were prepared by virtue facile mild ultrasound-assisted method. The obtained material (ANDC-900-10) conveys excellent pH-universal catalytic activity with onset potentials (Eonset) 1.01, 0.91 0.84 V vs. RHE, half-wave (E1/2) 0.87, 0.74 0.66 V RHE limiting current densities (JL) 5.50, 5.45 4.97 mA cm−2 in alkaline, neutral acidic electrolytes, respectively, prevailing over commercial Pt/C catalyst and, what's more, ANDC-900-10 displays preeminent methanol crossover resistance long-term stability broad pH range (0–13), thanks its abundant hierarchical nanopores well effective nitrogen doping high-density pyridinic-N graphitic-N. This work provides sonochemical insight underpinning eco-friendly approach rationally designing versatile metal-free toward ORR at various levels.