MnO2 nanostructures of different morphologies from amino acids-MnO4- reactions in aqueous solutions.
In this paper, we describe a simple method for the synthesis of MnO(2) nanostructures (quantum dots) by permanganate oxidations of methionine and cysteine. Upon addition of permanganate to a solution of reductant (methionine and/or cysteine), yellow-brown color species appears within the time of mixing which was stable for several weeks. The UV-vis spectroscopy and transmission electron microscopy (TEM) techniques were used to characterize the nature of color formed. TEM images show that the MnO(2) sol consists of aggregated spherical nonoparticles (size in the range ca<or=7 nm) of various forms. In addition, we observed the different morphologies of the MnO(2) nanostructures (MnO(2) nanoparticles, nanosheet, and fiber-like aggregated nanostructures) under different experimental conditions. The effect of various parameters, such as [H(+)], [MnO(4)(-)], and [reductants] was also investigated.
Khan
Zaheer
Z
Department of Chemistry, Faculty of Science, King Abdul Aziz University, PO Box 80203, Jeddah 21413, Saudi Arabia. drkhanchem@yahoo.co.in
Ahmed Al-Thabaiti
Shaeel
S
Yousif Obaid
Abdullah
A
Khan
Ziya Ahmad
ZA
D000465:Algorithms; D000596:Amino Acids / Q000737:chemistry*; D003545:Cysteine / Q000737:chemistry; D017895:Manganese Compounds / Q000737:chemistry*; D008715:Methionine / Q000737:chemistry; D046529:Microscopy, Electron, Transmission; D008956:Models, Chemical; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure; D010084:Oxidation-Reduction; D010087:Oxides / Q000737:chemistry*; D012996:Solutions / Q000737:chemistry; D013053:Spectrophotometry; D014867:Water / Q000737:chemistry
D000596:Amino Acids; D017895:Manganese Compounds; D010087:Oxides; D012996:Solutions; D014867:Water; C048856:permanganic acid; D008715:Methionine; D003545:Cysteine; C016552:manganese dioxide