摘要
为了制备高效和稳定的表面等离子体薄膜催化剂和探索其光催化和光电催化降解有机污染物的规律,用恒电流复合电沉积方法制备了Ag@AgBr/CNT/Ni薄膜。在负偏压和可见光作用下,以罗丹明B(RhB)为模拟污染物测定了薄膜的光电催化性能和稳定性。采用电化学技术和向反应体系加入活性物种捕获剂的方法对薄膜光电催化机理进行了探索。结果表明:最佳工艺下制备的Ag@AgBr/CNT/Ni薄膜具有极高的光电催化活性、极为显著的光电协同效应和良好的催化稳定性。催化反应3.0 min,Ag@AgBr/CNT/Ni膜电极光电催化RhB(c=5 mg/L)的降解率为93.8%,是相同时间Ag@AgBr/Ni薄膜降解率的5.4倍,是P25 TiO2/ITO多孔薄膜的23.4倍。相对于不加偏压的光催化,降解率提高了9.7倍。在保持薄膜催化活性基本不变的前提下,可重复使用5次。薄膜中具有突出SPR效应的纳米Ag和碳纳米管对溶解氧的催化还原作用是光电催化活性和稳定性提高的主要原因。在负偏压和可见光作用下,超氧负离子自由基、羟基自由基与染料正离子自由基对染料的光电催化降解有决定性作用。
In the purpose of preparing highly efficient and stable film plasma photocatalyst and exploring rule of its photocatalytic and photoelectrocatalytic degradation of organic pollutants,Ag@AgBr/CNT/Ni thin films were prepared by composite electroplating at a constant current.Its photoelectrocatalytic properties and stability were evaluated with Rhodamine B(RhB)as a model compound under the conditions of negative bias and visible light.Using electrochemical technique and adding active species trapping agents to the reaction system,the mechanism of photoeletrocatalytic degradation for the film was explored.The results show that the Ag@AgBr/CNT/Ni thin film prepared under the optimized conditions exhibits very high photoeletrocatalytic activity,remarkable Photoelectric synergistic effect and superior catalytic stability to decompose RhB.At optimum negative bias(?0.12 V)and under visible light irradiation in 3.0 min,the photoeletrocatalytic degradation rate of the Ag@AgBr/CNT/Ni thin film(i.e.93.8%)is 5.4 times of that of Ag@AgBr/Ni thin film,and 23.4 times of that of P25 TiO2/ITO thin film.Compared with no cathodic bias,the photoeletrocatalytic degradation rate of the Ag@AgBr/CNT/Ni thin film to RhB is increased by 9.7 times.The photoeletrocatalytic activity keeps mostly unchanged after five recycled experiments.The improvement in photoelectrocatalytic activity for Ag@AgBr/CNT/Ni thin film can be mainly attributed to the catalysis of nano-Ag particles with outstanding SPR effect and carbon nanotubes in the film for the reduction of dissolved oxygen.The hydroxyl radical,the superoxide anion radical and the dye cationic radical have a decisive role on the photoelectrocatalytic degradation of dyes at negative bias under visible light.
作者
李爱昌
卢艳红
李青
曹冉
赵娣
LI Ai-chang;LU Yan-hong;LI Qing;CAO Ran;ZHAO Di(School of Chemistry and Material Science,Langfang Normal University,Langfang 065000,China)
出处
《中国有色金属学报》
EI
CAS
CSCD
北大核心
2020年第2期401-410,共10页
The Chinese Journal of Nonferrous Metals
基金
国家自然科学基金资助项目(51502125)
河北省自然科学基金资助项目(E2016408035)。
