活性炭负载Co3O4活化过一硫酸盐降解金橙G

通过浸渍煅烧法制备活性炭负载Co的活化剂(Co/AC),采用X射线衍射仪(XRD)、扫描电镜(SEM)及X射线能谱仪(EDS)技术对活化剂进行表征,发现Co主要以Co_3O_4的形式负载于活性炭表面,并利用Co/AC活化过一硫酸盐(PMS)产生硫酸根自由基(SO_4~-·)降解偶氮染料金橙G(OG),研究了活化反应机制及不同因素对OG降解的影响.结果表明,SO_4~-·在OG降解过程中起主要作用,并且随Co/AC用量、PMS浓度、温度的提高,OG降解效率明显增加.反应初始pH对降解OG有较大影响,当p H在4~8范围内,SO_4~-·均能有效降解OG,但在强酸碱条件下,则不利于OG降解.Cl~-对活化降解OG具有双重作用,低浓度时抑制降解,而在高浓度时促进降解.Co/AC在重复使用6次时仍具有较好活化性能.通过紫外可见光谱及气相色谱-质谱(GC/MS)对OG降解过程及中间产物进行了分析.

Activated Carbon Supported Co3O4 Catalysts to Activate Peroxymonosulfate for Orange G Degradation

Activated carbon supported cobalt catalysts (Co/AC) were prepared through wet impregnation and high temperature calcination methods. The X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) characterization results showed that Co₃O₄ was the major form of Co species distributed on AC. The performance of Co/AC was evaluated as catalyst to activate peroxymonosulfate (PMS) to produce sulfate radicals (SO₄^-·) for Orange G (OG) degradation in solution. The activation mechanism and several influential factors were also investigated. The results demonstrated that SO₄^-·played a dominant role in OG degradation. And the degradation efficiency of OG increased with increasing Co/AC dosage, higher PMS concentration or elevating reaction temperature. Initial pH had a significant effect on OG degradation, with pH range of 4 to 8 as the optimal pH for degradation. In addition, the strong acidic or alkaline conditions were unfavorable for OG degradation. A dual effect of chloride ions (Cl^-) was observed. The high Cl^- concentration promoted degradation, while low concentration led to inhibition. The Co/AC also exhibited excellent reusability and its activating performance toward PMS was still observed after 6 rounds of tests. Finally, the degradation process and intermediate products of OG were analyzed with UV-visible spectroscopy and gas chromatography-mass spectrometry (GC/MS).