Rapid sensing and recovery of palladium(II) using N,N-bis(salicylidene)1,2-bis(2-aminophenylthio)ethane modified sensor ensemble adsorbent

This study aims to develop a novel sensor ensemble adsorbent for rapid sensing and recovery of Pd(II) from water. A highly selective and efficient adsorbent was prepared by immobilization of the synthesized N,N-bis(salicylidene)1,2-bis(2-aminophenylthio)ethane ligand onto mesoporous silica monoliths and applied for successful detection and recovery of Pd(II) ions with high selectivity and sensitivity. The effects of various parameters such as pH, contact time, initial concentration, selectivity and sensitivity, on the detection and sorption of Pd(II) by the adsorbent were investigated. The solution pH played an important role for detection and sorption but the present captor worked well in acidic pH region at 3.50. The data clarified that the adsorbent was able to detected even ultra-trace Pd(II) ions, which was unique feature of the sensor ensemble adsorbent material. The adsorbent offered simple, one-step detection procedure without the need of highly sophisticated instruments. The adsorbent exhibited significant ion-selectivity toward the Pd(II) in multi mixture of spike solution as environmental samples. The results showed that the maximum sorption capacity was found at pH 3.50 and adsorbent was selectively adsorbed Pd(II) ions from binary and multi mixtures even in the presence of various competing ions. The sorption isotherm was well described and the maximum sorption capacity was as high as 163.13 mg/g. The adsorbent was stable without significant loss of sorption and recovery performances even after several reuses cycles.