Selective adsorption of zirconium from scandium by novel diphosphoryl-modified SBA-15 adsorbent

A novel method for selective adsorption of zirconium (Zr) from scandium (Sc) in HNO 3 solution was proposed by DPO/SBA-15-N adsorbent which was prepared with SBA-15 and diphosphoryl (DPO) groups through silane coupling method. The results of scanning electron microscopy-energy dispersive spectrometer (SEM-EDS), Brunauer-Emmet-Teller (BET), thermogravimetry (TG) analysis and digestion analysis indicate that DPO/SBA-15-N is an ordered mesoporous adsorbent with a large specific surface area (157.363 m 2 /g) and high functional group content (1.16 mmol/g). In adsorption experiments, DPO/SBA-15-N exhibits high adsorption capacity ( Q = 130.23 mg/g), high separation factor (SF Zr/Sc = 6402) and high adsorption speed (reaching equilibrium within 10 min) for Zr(Ⅳ) in 6 mol/L HNO 3 medium, and the adsorption is better consistent with pseudo-second-order model and Langmuir model. According to the analysis of Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS) results, the P‒O and P=O groups in diphosphoryl (DPO) groups play an important role in the selective adsorption process. In conclusion, the adsorbent prepared in this work has great potential for the selective adsorption of Zr(Ⅳ) from Sc(Ⅲ).