Synthesis of PbSO4 crystals by hydrogel template on postprocessing strategy for secondary pollution

Pb2+ ions pose a significant threat to the environment and public health. Removal and reuse of Pb2+ ions from the environment are major focuses of waste treatment. Here the poly(acrylonitrile-acrylamide-acrylic acid) hydrogel prepared via crosslinking polymerization was introduced to capture Pb2+ ions, then as an in situ template to induce the formation of PbSO4 crystals with special morphology successfully. The absorption efficiency of Pb2+ ions by hydrogel was tested. The results show at the conditions of initial pH 5, 25 °C, 1.578 mg Pb2+ ions was removed by per unit hydrogel mass. PbSO4 crystals were characterized by X-ray diffraction, Raman spectrum, scanning electron microscopy, transmission electron microscopy, and fluorescence spectrometer. The results indicate that the branch-type structure crystals were excellent crystalline and mainly oriented along (1 0 1) and (2 3 1) plane. The PL spectrum show emission peaks at 380 and 400 nm and indicate that the product may have applications in an electronic light device. This approach provides an inspiration on the post-processing of the secondary pollution.

► A postprocessing strategy for Pb2+ ions secondary pollution was proposed. ► Hydrogel was introduced to capture Pb2+ ions at suitable conditions. ► The Pb2+-adsorbed hydrogel was used as template to induce the formation of PbSO4. ► The branch-type PbSO4 crystals were synthesized successfully.