Anion-controlled sulfidation for decoration of graphene oxide with iron cobalt sulfide for rapid sonochemical dyes removal in the absence of light

作者：Molla Aniruddha; Li Yuanyuan; Khandelwal Mahima; Hur Seung Hyun; Chung Jin Suk^*

来源：Applied Catalysis A: General , 2018, 561: 49-58.

DOI：10.1016/j.apcata.2018.05.014

• Anion controlled
• Sulfidation
• Sonochemical dye removal
• Catalysis without light

Anion-controlled sulfidation was used to decorate graphene oxide with iron cobalt sulfide via a simple hydrothermal reaction. Anion exchange was carried out using sodium sulfide as an exchanger without any templates or backbone architecture, and in an easy and economical way. Interchange of oxalate, chloride, and hydroxide anions with sulfide anions was performed to tune the morphology of the materials, which subsequently affected their surface area (48.64-83.52 m(2)/g) and band gap (2.45-2.91 eV). Ultrasonically-cavity-induced degradation activity without light was rapid (1-3 min) for both positive dyes (rhodamine B and methylene blue), a negative dye (methyl orange), and their mixture. Degradation of the dyes and their mixture in the presence of the prepared samples was a pseudo first-order reaction with rate constant value from 0.780 to 1.702 min(-1) that followed the sequence FCS@GO-2 > FCS@GO-1 similar to FCS@GO-3 and MB > RhB > MO for catalyst and dyes, respectively. By using terephthalic acid, it was found that the sono-Fenton process quickly generated reactive oxygen species (ROS) even in absence of light. The ROS production was greater for FCS@GO-2 than FCS@GO-1 or FCS@GO-3, consistent with the catalytic activities of the different catalysts. The prompt production of ROS resulted in a very active process, and the presence of mixed valance states of iron and cobalt resulted in an effective and stable process. It is the synergistic effect of the catalyst that allowed effective breakdown of dyes even in absence of light. The auto-cleaning effect of sonication allowed reuse of the decorated graphene oxide for at least five cycles.

• 出版日期2018-7-5