N、S共掺杂碳基高效氧还原催化剂的制备

杂原子掺杂碳基氧还原（ORR）催化剂具有代替Pt基催化剂的巨大潜力。以硫掺杂g-C₃N₄（S-doped g-C₃N₄， S-g-C₃N₄）作为硫源和氮源，以三嵌段共聚物P123作为碳源，通过简单的高温热解法成功制备了N、S共掺杂碳（N， S co-doped carbon， NSC）催化剂，并考察了热解温度对制备的NSC催化剂ORR性能的影响。材料表征结果显示:温度为1 000 ℃时制备的催化剂NSC-1000具有较高的氮含量和硫含量及最大的比表面积；电化学测试结果显示:NSC-1000具有最佳的ORR性能，在0.1 mol/L KOH溶液中半波电位（half-wave potential， E1/2）高达0.888 V，且经10 000圈循环伏安扫描后E1/2仅负移12 mV，表现出极佳的活性和稳定性。此外，旋转环盘电极测试结果显示:NSC-1000催化剂主要以四电子反应路径催化ORR的发生。本实验为制备N、S共掺杂碳基高效ORR催化剂提供了新的思路。

Preparation of N， S Co-doped Carbon as Highly Efficient Catalyst for Oxygen Reduction

Heteroatom-doped carbon catalysts have shown great potential to replace Pt-based catalysts for oxygen reduction reaction （ORR）. Herein， N， S co-doped carbon （NSC） catalysts were successfully synthesized via a simple high-temperature pyrolysis method with S-doped g-C₃N₄ （S-g-C₃N₄） serving as the nitrogen and sulfur sources and triblock copolymer P123 as the carbon source. The effect of pyrolysis temperature on the ORR performance of NSC catalyst was investigated. Characterization shows that the NSC catalyst synthesized at 1 000 ℃ （NSC-1000） has relatively high nitrogen and sulfur content as well as the largest specific surface area. It exhibits the highest ORR activity in alkaline media with a half-wave potential （E1/2） of 0.888 V， and its E1/2 decreases only 12 mV after 10 000 potential cycles， showing excellent catalytic activity and durability. Rotating ring-disk electrode measurement demonstrates the dominant ORR mechanism for NSC-1000 is 4e- transfer. This work provides a novel route for synthesizing highly efficient N， S co-doped carbon catalysts for ORR.