Zinc (Zn) is an essential nutrient for living organisms1, however, an excess supply of Zn can lead to toxic effect on plants234 and microorganisms56 in soil. Due to anthropogenic activities (such as industrial activities, sludge application, waste water irrigation, etc.3), Zn can be easily released into soil environment7, which could pose a threat to the health of ecosystems8 and even to human beings910. As free Zn ions are the main species for Zn toxicity15, the immobilization of free Zn ions by some materials would reduce its bioavailability and toxicity in soil. Thus, materials which are effective in Zn immobilization should be developed.