Preparation of 4-Amino-3-hydrazino-1,2,4-triazol-5-thiol-Modified Graphene Oxide and Its Greatly Enhanced Selective Adsorption of Gallium in Aqueous Solution.

Efficient recovery of gallium (Ga) from vanadium slag processing residue (VSPR) solution is of great significance for environmental protection and resource utilization, but improving its selective adsorption against the coexisting Sc 3+ and In 3+ is still challenging. Herein, a novel adsorbent consisting of 4-amino-3-hydrazino-1,2,4-triazol-5-thiol (AHTZT)-modified graphene oxide (GO-AHTZT) was successfully synthesized that exhibits a higher adsorption selectivity for Ga 3+ in VSPR solution with coexisting Sc 3+ and In 3+ . Under optimal conditions, the adsorption capacity of GO-AHTZT for Ga 3+ can reach 23.92 mg g -1 , which is 4.9 and 12.6 times higher than that for Sc 3+ (4.87 mg g -1 ) and In 3+ (1.90 mg g -1 ) adsorption, indicating the excellent anti-interference ability of GO-AHTZT against Sc 3+ and In 3+ . The process and mechanism of Ga 3+ adsorption onto GO-AHTZT was also studied and discussed in detail. By measuring the adsorption process and by characterizing the adsorbent before and after adsorption, we demonstrate that the selective interaction between the Ga 3+ - and N-containing groups in AHTZT is the main reason for the improved adsorption selectivity. This work opens up an avenue for the design and synthesis of highly selective adsorbents for Ga 3+ in complex VSPR solutions.