New Synthetic Route, Characterization, and Electrocatalytic Activity of Nanosized Manganite
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- 作者：Vincent Mark B. Crisostomo ; J. Katana Ngala ; Shaun Alia ; Arthur Dobley ; Christine Morein ; Chun-Hu Chen ; Xiongfei Shen ; Steven L. Suib
- 刊名：Chemistry of Materials
- 出版年：2007
- 出版时间：April 3, 2007
- 年：2007
- 卷：19
- 期：7
- 页码：1832 - 1839
- 全文大小：389K
- 年卷期：v.19,no.7(April 3, 2007)
- ISSN：1520-5002
文摘
Nanosized MG SRC="/images/gifchars/gamma.gif" BORDER=0 >-MnOOH (manganite) has been synthesized by a new route via the reduction of KMnO4with sucrose and MnSO4 in acidic medium under refluxing conditions for 4 and 6 h. Characterization ofthese manganite materials using XRD, FESEM, TEM, TGA, and IR were carried out. The obtainedmanganite samples using the new route were compared against a conventionally prepared one wheresynthesis involved the oxidation of MnSO4 with a H2O2 solution in a basic medium. Two new syntheticmethods were developed, one involving addition of KMnO4 into a solution of both sucrose and MnSO4while the other involved addition of KMnO4 solution into sucrose only followed by addition of MnSO4(s). The latter method yielded smaller particles (up to 30 nm) than the former method (up to 80 nm) andthe conventionally prepared manganite (up to 50 nm). The synthesized manganite materials exhibitedpromising characteristics when tested as electrocatalysts in the reduction of O2. The larger particles gavehigher peak currents in CV. When incorporated in Yardney's medium-sized lithium-air battery, the largerparticles gave higher specific capacity (up to 2.2 A·h/g), which corresponds to about a 38% increase inspecific energy of the battery when compared to a battery where no manganite was incorporated.