Synthesis of zeolite-based Cu/Fe-X from coal gangue for Fenton-like catalytic degradation of Rhodamine B

In this paper, coal gangue, a solid waste is used as raw material to provide silicon and aluminum sources for synthesis of zeolite. A coal gangue zeolite based Cu/Fe-X catalyst is successfully prepared by immersion-calcination method, which is used to remove Rhodamine B from aqueous solution. The characterization results show that Cu and Fe have been successfully loaded on zeolite, not damaged its structure, and these nanoparticles are highly dispersed and low crystallinity. This special structure will enhance its catalytic ability to activate H 2 O 2 . The experiment showed that hydroxyl radical (•OH) was the main active species for catalytic degradation of Rhodamine B, and the circulation of Cu 2+ to Cu 1+ and Fe 3+ to Fe 2+ could synergistically produce •OH. Furthermore, the redox potential of Cu 1+ and Cu 2+ is lower than Fe 2+ and Fe 3+ , which can promote Fe 3+ circulate to Fe 2+ , further promote Fe 2+ to activate H 2 O 2 to decompose into •OH, and overcome the speed limiting step of Fenton-Like catalytic reaction. The Cu/Fe-X catalyst can activate H 2 O 2 in wide pH range (1–10). Under optimal conditions the catalytic degradation rate can reach 99.9%, and the TOC removal rate is as high as 98.5%. Therefore, Cu/Fe-X/H 2 O 2 system can effectively remove organic dyes, and has a high industrial application prospect.