EB/g-C_(3)N_(4)/Fe_(3)O_(4)复合光催化剂的制备及其在铬污染土壤中的应用  

Preparation of EB/g-C_(3)N_(4)/Fe_(3)O_(4)Composite Photocatalyst and its Application in Chromium Contaminated Soils

作　　者：尚荣刚 廖辉伟 周艳娜[1,2] 周宇 黄晓枫 SHANG Ronggang;LIAO Huiwei;ZHOU Yanna;ZHOU Yu;HUANG Xiaofeng(State Key Laboratory of Environmentally-friendly Energy Materials,Southwest University of Science and Technology,Mianyang 621010,Sichuan,China;School of Materials Science and Engineering,Southwest University of Science and Technology,Mianyang 621010,Sichuan,China)

机构地区：[1]西南科技大学环境友好能源材料国家重点实验室,四川绵阳621010 [2]西南科技大学材料科学与工程学院,四川绵阳621010

出　　处：《西南科技大学学报》2021年第1期16-22,84,共8页Journal of Southwest University of Science and Technology

基　　金：环境友好能源材料国家重点实验室资助项目(19fksy01121)。

摘　　要：采用水热法将g-C_(3)N_(4)和Fe_(3)O_(4)负载在剥离膨润土(EB)载体上,制备出具有光催化活性的EB/g-C_(3)N_(4)/Fe_(3)O_(4)磁性复合材料,进一步将其用于还原土壤中的高价态铬离子,考察了不同土壤pH值、土壤初始Cr(Ⅵ)含量、催化剂剂量等因素对土壤中Cr(Ⅵ)光还原率的影响。实验结果表明:在500 g Cr(Ⅵ)含量为20 mg/kg,pH值为6.15的土壤中,投加Fe_(3)O_(4)含量为30%的EB/g-C_(3)N_(4)/Fe_(3)O_(4)(EB/g-C_(3)N_(4)/Fe_(3)O_(4)-30%)复合材料1.5 g,光照250 min时,土壤中Cr(Ⅵ)的光还原率可达97%。光还原土壤中Cr(VI)的动力学分析表明:Cr(Ⅵ)的光还原符合Langmuir-Hinshelwood(L-H)动力学模型,相关系数(R 2)为0.997。复合光催化剂材料EB/g-C_(3)N_(4)/Fe_(3)O_(4)-30%循环使用3次后,其光还原能力和磁回收率仍然保持较高水平。制备的催化剂复合材料EB/g-C_(3)N_(4)/Fe_(3)O_(4)具有用于铬污染土壤治理的应用前景。The EB/g-C_(3)N_(4)/Fe_(3)O_(4)magnetic composites with photocatalytic activity were prepared by hydrothermal loading of g-C_(3)N_(4)and Fe_(3)O_(4)onto an exfoliated bentonite(EB)carrier,which was further used to reduce high valence chromium ions in soil,and the effects of different soil pH,initial Cr(VI)content of soil,and catalyst dose on the photoreduction rate of Cr(VI)were investigated respectively.The experimental results are as follows:when 1.5 g of EB/g-C_(3)N_(4)/Fe_(3)O_(4)(EB/g-C_(3)N_(4)/Fe_(3)O_(4)-30%)composite with Fe_(3)O_(4)content of 30%is injected into 500 g of soil with Cr(VI)content of 20 mg/kg,pH 6.15,and light time of 250 min,the photoreduction rate of Cr(VI)reaches 97%.In addition,the kinetic analysis of photoreduction of Cr(VI)in the soil shows that the photoreduction of Cr(VI)is consistent with Langmuir-Hinshelwood(L-H)kinetic model with a correlation coefficient(R 2)of 0.997.The composite photocatalyst material EB/g-C_(3)N_(4)/Fe_(3)O_(4)-30%still has high photoreduction ability and magnetic recovery after three cycles of use.Therefore,as-prepared photocatalytic composites EB/g-C_(3)N_(4)/Fe_(3)O_(4)are expected to have a wide application in chromium-contaminated soil.

关 键 词：土壤修复 铬污染土壤 g-C_(3)N_(4) 剥离膨润土 光催化 Fe_(3)O_(4) 

分 类 号：X53[环境科学与工程—环境工程]