均匀分散的纳米银/介孔氮化碳复合微粒的协同光催化性能研究

为了有效还原污染水中的硝基化合物和光解水制氢,采用浸渍法制备纳米银/介孔石墨相氮化碳(Ag/mpg-C_3N_4)复合微粒,继而通过简单吸附法制备Ag/5-OH-ZnTPP/mpg-C_3N_4复合微粒,利用BET,SEM,XRD和XPS等表征方法对所制备复合微粒的形貌、微观结构和组成进行测试,结果显示,介孔石墨相氮化碳(mpg-C_3N_4)呈多孔片层状,纳米银粒子(AgNPs)均匀分散于mpg-C_3N_4表面及片层间。通过UV-vis DRS,PL和PT等表征方法对Ag/5-OH-ZnTPP/mpg-C_3N_4复合微粒的光电性能进行测试,结果表明,AgNPs的引入和锌卟啉的表面敏化作用提高了mpg-C_3N_4基体对可见光的利用率。选用对硝基苯酚还原和光解水制氢为模型反应,经贵金属沉积改性及锌卟啉表面敏化改性后显著提高了mpg-C_3N_4基体的光催化活性。因此,Ag/5-OH-ZnTPP/mpg-C_3N_4复合微粒对4-NP的还原反应及光解水制氢具有高效催化活性。

Research of synergistic photocatalytic properties of silver/mesoporous carbon nitride nanocomposite particles with uniform dispersion

In order to effectively reduce nitro compounds in contaminate water and produce hydrogen from water, Ag/mpg-C₃N₄ nanocomposite particles are prepared by impregnation method, and 5-OH-ZnTPP is loaded on the surface of Ag/mpg-C₃N₄ to prepare Ag/5-OH-ZnTPP/mpg-C₃N₄ composite particles. The morphology, microstructure and composition of as-prepared nanocomposite particles are characterized by BET, SEM, XRD and XPS. The results show that the mpg-C₃N₄ is lamellar structure with porous, while the silver nanoparticles are dispersed on the surface or between the lamellar of the mpg-C₃N₄. The photoelectric property of the Ag/5-OH-ZnTPP/mpg-C₃N₄ nanocomposite particles is also characterized by UV-vis DRS, PL and PT, respectively. The results reveal that the visible-light utilization of mpg-C₃N₄ are improved by the introduction of silver nanoparticles and the sensitization of porphyrin. The catalytic activities are examined by using the reduction of 4-NP and the photocatalytic H2 production as model reactions, which demonstrates that the photocatalytic activity of mpg-C₃N₄ is enhanced after modified by silver nanoparticles and sensitized with dye porphyrins. Ag/5-OH-ZnTPP/mpg-C₃N₄ nanocomposite particles have high catalytic activity for the reduction of 4-NP and hydrogen production.