FeNi-LDH Coated With Orange-Peel Carbon Aerogel for Oxygen Evolution Reaction.

In this work, the waste orange-peel was used as carbon source, and the orange-peel derived carbon material can be obtained through simple pyrolysis. Then, we designed the structure of orange-peel carbon aerogel grown on iron-nickel layered double hydroxides in situ to achieve the effect of carbon coating (FeNi-LDH/CA). The oxygen evolution reaction catalytic performance of FeNi-LDH/CA is excellent, far exceeding that of commercial RuO2. In 1 M KOH, the overpotential of FeNi-LDH/CA is only 250 mV (10 mA cm-2), obviously better than that of commercial RuO2 (295 mV). FeNi-LDH/CA shows good cycling stability, and after long-term i-t testing, the performance only decays by 3 % after running at 100 mA cm-2 for 100 h. When used as an anode, the voltage of water-splitting is only 1.48 V at 10 mA cm-2. The rechargeable liquid zinc-air battery based on Pt/C-FeNi-LDH/CA catalyst has higher open-circuit voltage (1.543 V) and galvanostatic discharge capacity at 1.23 V (830 min, 10 mA cm-2). Moreover, the zinc-air battery based on Pt/C-FeNi-LDH/CA has a small charge-discharge voltage gap (0.65 V) at 10 mA cm-2, after 200 consecutive cycles (66 h), the charge-discharge voltage gap only increased by about 30 mV, indicating good cycling stability.