Recycling heavy metal ions by ultrathin nanosheet-assembled calcium silicate hydrate for the degradation of organic pollutants in wastewater via Fenton-like reactions

It is highly desirable to synergistically remove heavy metal ions and organic pollutants by low-cost, easy-access and high-performance technique. Here, we demonstrate a facile "adsorbent-to-catalyst" conversion strategy for Fenton-like degradation of organic pollutants using hierarchically nanosheet-assembled calcium silicate hydrate (CSH) architectures, which are prepared in large scale by a simple one-step room-temperature solid-phase method. The hierarchical CSH architectures exhibit excellent adsorption capacity for Ni2+, Cu2+, Co2+ with adsorption capacities of 406, 330 and 264 mg·g−1, respectively. The excellent adsorption capability results from the ion exchange between heavy metal ions and Ca2+ released by CSH architectures. Furthermore, as a case study, the collected CSH-Cu can be converted into a catalyst by simply heating at 450 °C. The resulted catalyst exhibits an excellent Fenton-like degradation ability for Rhodamine B with an efficiency of about 90% within 60 min. This study provides an environmentally friendly strategy of "adsorbent-to-catalyst" for efficient water purification.