漂浮型Ag2CrO4-g-C3N4-TiO2/膨胀珍珠岩可见光催化材料除藻性能

以Al₂O₃改性的膨胀珍珠岩(mEP)为载体，采用溶胶凝胶-浸渍沉积法制备Ag₂CrO₄-g-C₃N₄-TiO₂/mEP漂浮型可见光催化材料。对制备的光催化材料使用XRD、N₂吸附/脱附、FESEM-EDS、XPS和UV-vis DRS等分析方法进行材料表征。实验结果表明，不同的Ag₂CrO₄含量可对复合催化剂的晶型和比表面积产生影响，过高的Ag₂CrO₄可在催化剂的表面形成团聚颗粒不利于催化剂对藻细胞的吸附和光催化灭活。以铜绿微囊藻为处理对象，光催化剂中Ag₂CrO₄/TiO₂的理论摩尔比为0.05，初始藻细胞浓度为2.75×106 cells/mL时，单纯暗吸附8 h藻细胞的去除率为10.3%，在吸附和光催化的协同作用下，藻细胞的去除率可达81.88%。光催化除藻过程中起主要作用的为光生空穴h+，该催化剂在重复利用三次后对藻细胞仍有72.19%的去除率，催化剂有较好的稳定性。 

Photocatalytic inactivation of algae using floating visible-light-responsive photocatalyst Ag2CrO4-g-C3N4-TiO2/modified expanded perlite

Based on Al₂O₃ modified expanded perlite (mEP), floating visible-light responsive photocatalysts Ag₂CrO₄-g-C₃N₄-TiO₂/mEP were prepared via a sol-gel-impregnation deposition method. The synthesized photocatalysts were characterized using XRD, N₂ adsorption/desorption, FESEM-EDS, XPS and UV-vis DRS. The results show that the concentration of Ag₂CrO₄ has influence on the crystal structure and specific surface area of the photocatalysts. High concentration of Ag₂CrO₄ could form agglomerated particles on the surface of the photocatalyst which are not conductive to the adsorption and photocatalytic inactivation of algae. When the theoretical molar ratio of Ag₂CrO₄/TiO₂ is 0.05 and the initial algal cell concentration of Microcystis aeruginosa is 2.75×106 cells/mL, the removal rate of algal after adsorption for 8 h was 10.3%. Under the synergistic effect of adsorption and photocatalysis, the removal rate of algal could reach 81.88%. The inactivation of algae cell mainly ascribed to the attack by the photo-generated holes (h+). The removal rate of algae could reach to 72.19% after three successive cycles which indicated the stability of the photocatalst.