Facile synthesis of novel porous graphene-like carbon hydrogel for highly efficient recovery of precious metal and removal of organic dye

New strategies for adsorbing environmental pollutants such as Ag+ and organic dyes are still in urgent need. Based on this, we developed a highly efficient adsorbent, porous graphene-like carbon (PGC), by a simple cat- alysis process. A three dimensional porous graphene-like carbon hydrogel (3D-PGCH) was further obtained by introducing polyvinyl alcohol (PVA) and fully cross-linked via freeze-drying. The 3D-PGCH had a high adsorption capacity for Ag+ with an adsorption value of 234.32 mg g(-1) at pH 4 and 303 K. Its active ingredient PGC exhibited excellent adsorbing effect on methylene blue (MB), and the maximum adsorption was up to 13381.62 mg g(-1), about 32 times higher than that of using single PGC. Moreover, the adsorption-desorption experiment reflected a good recyclability of 3D-PGCH, whose adsorption capacity remained a high level after four cycle experiments. This study provides a positive choice for resource conservation and wastewater remediation.