Iron nitrate and nickel nitrate 1,000-ppm (1-mg/mL) standard solutions were purchased from EM Science (Gibbstown, New Jersey) and Absolute Standards, Inc.
Iron nitrate and nickel nitrate solutions were used to bathe the wood char for the purpose of improving the production yield.
Iron nitrate.--Figure 6 illustrates the background-subtracted XRD patterns of the wood char showing the effect of being pre-impregnated with [Fe.sup.3+] ions.
At high temperatures, the iron nitrate decomposed into iron oxide, and most of this iron oxide was further reduced to iron by the abundant carbon sources.
This is analogous to observations of iron nitrate. Several diffraction peaks, which closely match the peaks of nickel nitrate hydrate, were observed in Sample K.
The impregnation of iron nitrate or nickel nitrate into the wood char significantly improved the yield of these carbonaceous nanoparticles.