Bai Fan, He Yuxiu, Xu Lincheng, Wang Yue, Wang Yan, Hao Zhanzhong, Li Fan
Faculty of Environment and Life Sciences, Beijing University of Technology Beijing 100124 P. R. China
Beijing Office of Metrohm China Ltd Beijing 100085 P. R. China.
RSC Adv. 2022 Jan 18;12(4):2408-2415. doi: 10.1039/d1ra08618a. eCollection 2022 Jan 12.
Transition metal oxide nanomaterials or nanocomposites containing transition metal oxides have the potential to replace traditional catalysts for electrochemical applications, photocatalysis, and energy storage. Amorphous manganese oxide catalysts were prepared photochemical metal-organic deposition (PMOD). Through XRD, SEM-EDS, Raman spectroscopy, FTIR spectroscopy, HRTEM-EDS, and XPS, we confirmed that amorphous manganese oxide catalysts were successfully prepared. Amorphous catalysts prepared with different photolysis times were compared in terms of their performance for the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER), and catalyst MnO -PMOD48 showed the best performance because of its high Mn proportion and electrochemically active surface area. MnO -PMOD48 showed better ORR/OER performance than the crystalline MnO and MnO /TiO catalysts from our previous work. Following our previous work on crystalline manganese oxide catalysts, we added TiO during the PMOD process with 48 h of treatment and obtained the amorphous catalyst MnO /TiO-PMOD. MnO /TiO-PMOD was supported by TiO particles, which led to improved stability. The ORR/OER catalytic activity of MnO /TiO-PMOD was better than that of crystalline catalyst MnO /TiO-300, which was the best crystalline catalyst in our previous work. We also compared lithium-oxygen batteries assembled with MnO /TiO-PMOD and MnO /TiO-300. The battery performance tests confirmed that the amorphous manganese catalyst had better ORR/OER bifunctional catalytic performance than the crystalline manganese catalyst because of its high defect state with more abundant edge active sites and more surface-exposed catalytic active sites.
过渡金属氧化物纳米材料或含有过渡金属氧化物的纳米复合材料有潜力取代传统催化剂，用于电化学应用、光催化和能量存储。通过光化学金属有机沉积（PMOD）制备了非晶态锰氧化物催化剂。通过XRD、SEM-EDS、拉曼光谱、FTIR光谱、HRTEM-EDS和XPS，我们证实成功制备了非晶态锰氧化物催化剂。比较了不同光解时间制备的非晶态催化剂在氧还原反应（ORR）和析氧反应（OER）方面的性能，催化剂MnO-PMOD48因其高Mn比例和电化学活性表面积而表现出最佳性能。MnO-PMOD48在ORR/OER性能方面优于我们之前工作中的结晶MnO和MnO/TiO催化剂。继我们之前关于结晶锰氧化物催化剂的工作之后，我们在48小时处理的PMOD过程中添加了TiO，得到了非晶态催化剂MnO/TiO-PMOD。MnO/TiO-PMOD由TiO颗粒支撑，这提高了稳定性。MnO/TiO-PMOD的ORR/OER催化活性优于结晶催化剂MnO/TiO-300，后者是我们之前工作中最好的结晶催化剂。我们还比较了用MnO/TiO-PMOD和MnO/TiO-300组装的锂氧电池。电池性能测试证实，非晶态锰催化剂由于其高缺陷状态，具有更丰富的边缘活性位点和更多表面暴露的催化活性位点，因此比结晶锰催化剂具有更好的ORR/OER双功能催化性能。
