Sulfur-containing materials are very attractive for the efficient decontamination of some heavy metals. However, the effective and irreversible removal of Cd 2+ , coupled with a high uptake efficiency, remains a great challenge due to the relatively low bond dissociation energy of CdS. Herein, we propose a new strategy to overcome this challenge, by the incorporation of Cd 2+ into a stable Zn x Cd 1-x S solid solution, rather than into CdS. This can be realised through the adsorption of Cd 2+ by ZnS nanoparticles, which have exhibited a Cd 2+ uptake capacity of approximate 400 mg g −1. Through this adsorption mechanism, the Cd 2+ concentration in a contaminated solution could effectively be reduced from 50 ppb to < 3 ppb, a WHO limit acceptable for drinking water. In addition, ZnS continued to exhibit this noteworthy uptake capacity even in the presence of Cu 2+ , Pb 2+ , and Hg 2+. ZnS displayed high chemical stability. Particles aged in air for 3 months still retained a > 80% uptake capacity for Cd 2+ , compared with only 9% uptake capacity for similarly-aged FeS particles. This work reveals a new mechanism for Cd 2+ removal with ZnS and establishes a valuable starting point for further studies into the formation of solid solutions for hazardous heavy metal removal applications.

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