Fig. 8. The color changes of TPTZ solution after reacting with Fe2+, Cu2+, Ni2+ and Co2+ ions. (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article.)
Fig. 8. The color changes of TPTZ solution after reacting with Fe2+, Cu2+, Ni2+ andCo2+ ions. (For interpretation of the references to color in this figure legend, thereader is referred to the web version of this article.)