P25复合钴铝水滑石催化剂的制备及其用于光催化降解RhB  

P25/LDH composites and its performance for photocatalytic degradation of RhB

作　　者：刘敏 曹炳伟 武化民 康长安 LIU Min;CAO Bingwei;WU Huamin;KANG Changan(Center of Ecology and Environment Monitoring of Jiangxi Province,Nanchang 330039,China;Center of Ecological Environment Emergency Investigation of Jiangxi Province,Nanchang 330039,China)

机构地区：[1]江西省生态环境监测中心,江西南昌330039 [2]江西省生态环境应急调查中心,江西南昌330039

出　　处：《南昌大学学报（工科版）》2022年第4期315-319,325,共6页Journal of Nanchang University(Engineering & Technology)

基　　金：国家环境保护重金属污染监测开放基金项目(SKLMHM202215)。

摘　　要：鉴于罗丹明B(RhB)对于环境的污染,以商用二氧化钛(P25)为基体,通过水热的方式制备二氧化钛/钴铝水滑石异质结催化剂(P25/LDH),并通过光催化降解RhB表征其光催化性能。利用X射线衍射仪、扫描电子显微镜、紫外可见分光光度计、电化学工作站等对样品的晶体结构、微观形貌、光吸收、电化学性能等进行测试,并计算其能带结构,探究P25/LDH催化剂光催化反应机制。结果表明:相比于纯相P25,P25/LDH复合材料具有多孔结构,且对光的吸收更高,P25的质量分数为62%时,复合材料的催化效率最高,光照15 min后RhB的质量浓度为1.6 mg·L^(-1)。UV-DRS图谱显示,LDH能够扩展材料对光的吸收,相比于纯相P25,复合材料在400 nm以后也有吸收峰提升了对光的利用率。通过对样品的能带结构分析可得,由于P25的导带及价带位置均低于LDH的导带及价带,可以判断P25和LDH之间形成type-Ⅱ型异质结,这可以抑制光生载流子的复合,提高其分离度,从而提升催化剂对RhB的降解率。To solve the environment problem caused by RhB,a novel P25/LDH heterojunction catalyst was prepared by hydrothermal method based on TiO2(P25),and its photocatalytic performance was evaluated by the degradation of RhB.XRD,SEM,UV-DRS,and electrochemical performance were characterized to explore the photocatalytic mechanism of P25/LDH catalyst.The results showed that the P25/LDH composites had a porous structure and a higher absorption of light compared with pristine P25.The catalytic efficiency reached the highest when the mass fraction of P25 was 62%,as the mass concentration of RHB achieved 1.6 m·L^(-1)after 15 min.UV-DRS presented that the light absorption edge were also widen beyond 400 nm after the introduction of LDH,which means the higher utilization of light.The calculation of band structure presented that the positions of VB and CB for P25 are both lower than that of LDH,this suggests a type-Ⅱ heterojunction was formed between P25 and LDH,which result in a higher charge separation, finally lead to an enhanced RhB degradation rate.

关 键 词：光催化降解 二氧化钛 水滑石 罗丹明B 异质结 

分 类 号：X703[环境科学与工程—环境工程]