Effect of carrier and axial ligand on the photocatalytic activity of cobalt thioporphyrazine  

载体和轴向配体对八正丁硫基含硫四氮杂钴卟啉光催化活性的影响（英文）

作　　者：刘义[1] 周泫沐 张泽会[1] 张丙广[1] 邓克俭[1] 

机构地区：[1]中南民族大学化学与材料科学学院,催化材料科学国家民委-教育部重点实验室,湖北武汉430074

出　　处：《Chinese Journal of Catalysis》2017年第2期330-336,共7页催化学报（英文）

基　　金：supported by National Natural Science Foundation of China (20977115, 21272281);Natural Science Foundation of Hubei Province (2014CFB919);the Science and Technology Plan Innovation Team of Wuhan City (2015070504020220)~~

摘　　要：The photocatalytic activity of cobalt octakis（butylthio） porphyrazine（CoPz（BuS）8） was assessed through photodegradation of the dye rhodamine B（RhB） in water under irradiation with a Xe lamp and aerated conditions.The photocatalytic activity of CoPz（BuS）8 loaded on Al2O3 or SiO2@Fe3O4nanoparticles or coordinated with an axial azide ligand was also investigated.The results demonstrated that the photocatalytic activity of CoPz（BuS）8 loaded on Al2O3 was higher than that loaded on [e-mail] kinetic curves of RhB degradation in aqueous solutions at different pH indicated the pseudo first-order kinetics of the reaction.The highest degradation rate for CoPz（BuS）8 loaded Al2O3 at pH = 4 after 160 min was 84.6%.However,the advantages of easier separation and recycling as well as the ability to terminate the reaction at any time for the CoPz（BuS）8 loaded SiO2@Fe3O4 cannot be ignored.When electron-rich NaN3 was coordinated with CoPz（BuS）8 as an axial ligand and loaded on Al2O3,the resulting catalyst produced more active oxygen species such as O2^- and HO· to promote the quicker degradation of RhB than that by the other catalysts.For the N3-coordinated CoPz（BuS）8 loaded on Al2O3,the reactions at pH = 4 and 7 distinctly deviated from first-order kinetics,and the degradation rate reached 77.6%after 80 min at pH = 4.将八正丁硫基四氮杂钴卟啉(CoPz(BuS)_8)分别负载到载体Al_2O_3和SiO_2@Fe_3O_4以及与配体叠氮轴向配位,并在模拟太阳光的氙灯照射下通入空气,通过降解水中染料罗丹明B(RhB)来评估其光催化活性.载体Al_2O_3有高的比表面积和好的化学惰性,其表面还存在一些氧空位以促进氧化反应中活性氧的流动;虽然磁性纳米颗粒(MNP)Fe_3O_4表面存在酸腐蚀和自聚集问题,但在MNP外面包覆一层具有较好吸附和稳定性能的SiO_2膜,因而也是较好的催化剂载体.富电子的NaN_3可增强某些缺电子的过渡金属大环络合物催化氧化反应,是较好的轴向配体.在不同pH水溶液中降解RhB的动力学曲线表明,反应为准一级.复合催化剂CoPz(BuS)_8/Al_2O_3上RhB降解率在pH=4时经160 min达到84.6%,在pH=7和pH=9时经12 h分别达到65.1%和49.2%.复合催化剂CoPz(BuS)_8/SiO_2@Fe_3O_4的透射电镜(TEM)和红外光谱(FTIR)表征表明,SiO_2包覆完整,复合粒子在1083 cm^(-1)有SiO_2的吸收峰,在2910 cm^(-1)有CoPz(BuS)_8的烷基吸收峰,说明NMP上存在SiO_2和CoPz(BuS)_8,表明复合粒子制备成功;其光催化反应的降解率在pH=4,7和9时经12 h分别达到66.3%,41.9%和29.6%.尽管CoPz(BuS)_8负载到Al_2O_3上比负载到SiO_2@Fe_3O_4上活性高,但后者分离容易,可重复使用,尤其是可随时终止反应.这意味着不同的污染物可用性能不同的催化剂/MNP系统去除,而催化剂可高效回收.当富电子的NaN_3与CoPz(BuS)_8在轴向配位并负载到Al_2O_3上时,CoPz(BuS)_8的紫外-可见光谱B带红移28 nm,Q带红移19nm,FTIR在2122 cm^(-1)出现一个-N=N^+=N^-特征吸收峰,临近S原子的烷基链-CH_2-的核磁峰从3.17 ppm移向低场4.17ppm,表明N_3^-配位成功.利用ESR自由基捕获技术发现,该复合催化剂能活化分子氧,产生比复合催化剂CoPz(BuS)_8/Al_2O_3更多的O_2^-和HO~·等活性物种.在pH=4和pH=7水溶液中的反应明显偏离了一级反应动力学,促进RhB的快速降解,在pH=4

关 键 词：Cobalt thioporphyrazine Photocatalytic activity ALUMINA SiO2@Fe3O4 Axial direction ligand Sodium azide 

分 类 号：O641.4[理学—物理化学] O643.36[理学—化学]