Z型SnO/g-C_(3)N_(4)光催化剂的制备及其性能研究

Preparation and properties of Z-scheme SnO/g-C_(3)N_(4)photocatalyst

通过热聚合法并辅助超声沉淀法,以g-C_(3)N_(4)为原料制备了SnO/g-C_(3)N_(4)复合光催化材料。利用XRD、FTIR、FESEM、DRS和PL等表征手段对制备的样品进行形貌和结构分析。以RhB为探针分子,在可见光下考察SnO/g-C_(3)N_(4)复合材料的光催化性能。结果发现,SnO/g-C_(3)N_(4)复合材料形成了Z型异质结,其光催化性能比单一g-C_(3)N_(4)显著提高,当RhB初始浓度10 mg/L,光催化剂用量为0.1 g/L时,在19 W的低功率紫外灯下辐射120 min后,RhB的降解效率可达93.28%,其反应速率常数为单一g-C_(3)N_(4)的6.2倍。自由基猝灭实验发现,在降解有机污染物时,SnO/g-C_(3)N_(4)中主要的活性物种为·OH和·O_(2)^(-),对SnO/g-C_(3)N_(4)光催化降解罗丹明B的反应机理也做了进一步探讨。

SnO/g-C_(3)N_(4)Composite photocatalytic materials were prepared from g-C_(3)N_(4) by thermal polymerization and assisted ultrasonic precipitation.The morphology and structure of the prepared samples were analyzed by XRD,FTIR,FESEM,DRS and PL.The photocatalytic properties of SnO/g-C_(3)N_(4) composites were investigated under visible light with RhB as probe molecule.The results showed that SnO/g-C_(3)N_(4) composite formed a Z-scheme,and its photocatalytic performance was significantly higher than that of single g-C_(3)N_(4).When the initial concentration of RhB was 10 mg/L and the amount of photocatalyst was 0.1 g/L,the degradation efficiency of RhB could reach 93.28%and the reaction rate constant was 6.2 times that of single g-C_(3)N_(4) after 120 min radiation under 19 W low-power UV lamp.The radical quenching experiment found that the main active species in SnO/g-C_(3)N_(4) were·OH and·O_(2)^(-).The reaction mechanism of photocatalytic degradation of Rhodamine B by SnO/g-C_(3)N_(4) was further discussed.