▎ 摘　　要

Specific ion exchangers/adsorbents are used to separate low concentration rubidium (Rb) resources from seawater or salt lakes, especially potassium cobalt hexacyanoferrate (KCoFC) with high adsorption capacity and selectivity for Rb+. However, there are great challenges in recovery from solution for powder form KCoFC. Herein, a new immobilization strategy was presented, and KCoFC was encapsulated by synthetic hydrogels of hydroxypropyl cellulose/polyvinyl alcohol/reduced graphene oxide (KCoFC-HPR). Scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, and X-ray photoelectron spectroscopy were employed to indicate the correct encapsulation of KCoFC. The adsorption behavior of KCoFC-HPR for Rb+ was investigated, and the results demonstrated that the process conformed to pseudo-second-order kinetic model and Langmuir isotherm model with the exchange of Rb+ and K+ as main adsorption mechanism. The maximum adsorption capacity for Rb+ on KCoFC-HPR achieved 211.2 mg g(-1) at 25 degrees C. The interference of lithium and sodium ions (Li+/Na+:Rb+ = 20:1) on the adsorption capacity proved negligible. Within 24 h, 77.9% of adsorbed Rb+ on KCoFC-HPR in 0.5 mol L-1 NH4Cl/HCl mixture was desorbed, and adsorption capacity for the regenerated sample was 88.1% of the initial sample.