ZnFe_(2)O_(4)光催化还原Cr(Ⅵ)及其机理研究  

Investigation on mechanism of photocatalytic reduction of Cr(Ⅵ)by ZnFe_(2)O_(4)

作　　者：王宏斌 侯岳茹 蒋良兴 刘芳洋 贾明 张宗良 WANG Hongbin;HOU Yueru;JIANG Liangxing;LIU Fangyang;JIA Ming;ZHANG Zongiang(School of Metallurgy and Environment,Central South University,Changsha 410083,China;Hunan Province Key Laboratory of Nonferrous Value-Added Metallurgy Changsha 410083,China)

机构地区：[1]中南大学冶金与环境学院,湖南长沙410083 [2]有色金属增值冶金湖南省重点实验室,湖南长沙410083

出　　处：《中南大学学报（自然科学版）》2023年第11期4295-4305,共11页Journal of Central South University:Science and Technology

基　　金：国家重点研发计划项目(2022YFC3900804);湖南省自然科学基金资助项目(2022JJ10074)。

摘　　要：以传统湿法炼锌过程中产生的Zn Fe_(2)O_(4)中浸渣为原料,经过预处理后应用于光催化还原Cr(Ⅵ)。采用XRD、FT-IR、SEM和XPS等检测手段对Zn Fe_(2)O_(4)进行表征,并对其光催化性能进行研究。研究了反应时间、EDTA加入量、固液比、溶液初始浓度和p H等参数对光催化还原Cr(Ⅵ)的影响。研究结果表明:Zn Fe_(2)O_(4)是n型半导体,禁带宽度为1.71 e V,其导带底电位(vs.RHE)为0.01 V,理论上可实现对Cr(Ⅵ)的还原。由于EDTA能够消耗空穴并形成[Cr-EDTA]~(3+)配合物,可实现Zn Fe_(2)O_(4)光生电子空穴对有效分离,从而大幅提升了Zn Fe_(2)O_(4)光催化还原Cr(Ⅵ)的性能。在EDTA加入量为0.1 m L、固液比为1 g/L、溶液初始质量浓度为20 mg/L、p H=3的优化条件下,Zn Fe_(2)O_(4)在120 min内对Cr(Ⅵ)的还原率达到97.95%。The leaching residue of ZnFe_(2)O_(4) produced in the process of traditional zinc hydrometallurgy was used as raw material for photocatalytic reduction of Cr(Ⅵ)after pretreatment.The sample was characterized by XRD,FT-IR,SEM and XPS etc,and its photocatalytic performance was also studied.The effects of reaction time,EDTA dosage,solid-liquid ratio,initial solution concentration and pH on the photocatalytic reduction of Cr(Ⅵ)were investigated.The results show that ZnFe_(2)O_(4) is a n-type semiconductor with a band gap of 1.71 eV and a conduction band edge(vs.RHE)of 0.01 V,which can theoretically reduce Cr(Ⅵ).Because EDTA can consume holes and form[Cr-EDTA]3+complex,the effective separation of photogenerated electron hole pairs has greatly improved the performance of ZnFe_(2)O_(4) in photocatalytic reduction of Cr(Ⅵ).Under the optimal conditions of 0.1 mL EDTA,solid-liquid ratio 1 g/L,and initial solution concentration 20 mg/L,pH=3,the reduction rate of Cr(Ⅵ)by ZnFe_(2)O_(4) reaches 97.95%within 120 min.

关 键 词：中浸渣 ZnFe_(2)O_(4) EDTA 光催化 Cr(Ⅵ)还原 

分 类 号：TF80[冶金工程—有色金属冶金]