Novel graphene oxide-based hydrogels for removal of dyes from water

Graphene oxide (GO) based hydrogels were synthesized by using 3,5-Diamino-1,2,4-triazole (HGO1) and 4-Amino-2,6-dihydroxypyrimidine (HGO2) as cross-linking agents and utilized as highly efficient adsorbents for methylene blue (MB) and acid yellow 42 (AY) dyes removal. The prepared hydrogels were characterized with thermogravimetric analysis (TGA) and the results showed the higher thermal stability of the HGO1 and HGO2 hydrogels in comparison to neat GO nanosheet. The batch adsorption experiments were performed to examine the removal efficiency of the adsorbents. The fast adsorption of dyes occurred during initial 1 hour with high removal efficiency of 88.35% and 79.40% for MB and AY, respectively. Reusability of the adsorbents was conducted through four successful cycles without significant loss of removal efficiency