超声共混合成Ni(HNCN)_(2)/BiVO_(4)复合可见光催化剂

Ultrasonic Blending Synthesis of Ni(HNCN)/BiVO Composite Visible-Light Induced Photocatalysts

采用化学沉淀法分别合成了Ni(HNCN)_(2)和BiVO_(4),然后通过超声共混制备了Ni(HNCN)_(2)/BiVO_(4)复合颗粒,利用XRD、SEM、红外光谱(FT-IR)和紫外-可见(UV-Vis)吸收光谱对复合光催化剂的结构进行表征,并研究其对于有机染料罗丹明B的可见光催化降解。结果表明,超声共混获得较小颗粒尺寸的Ni(HNCN)_(2)沉积在棒状BiVO_(4)表面形成异质结构。单一Ni(HNCN)_(2)的禁带宽度为2.64 eV,BiVO_(4)的禁带宽度为2.41 eV,Ni(HNCN)_(2)/BiVO_(4)复合颗粒的禁带宽度约为2.37 eV。相较于单一Ni(HNCN)_(2)和BiVO_(4)颗粒,复合颗粒禁带宽度变窄,更有利于对可见光的响应。在对罗丹明B的光催化降解过程中,Ni(HNCN)_(2)与BiVO_(4)按照摩尔比例1∶2合成的复合颗粒的光催化活性最强。光催化机理研究表明,匹配的能带结构促进光生电子和空穴在两相界面的流动,提高光催化效率。

Photocatalytic technology is gaining increasing attention as one of the key technologies in solving environmental pollution problems owing to its ability to completely decompose organic contaminants.In addition,the development of visible-light-driven photocatalysts has always been an important topic in photocatalytic fields.In this work,Ni(HNCN)_(2)and BiVO_(4)were synthesized using a simple chemical precipitation process,which was followed by the preparation of Ni(HNCN)_(2)-BiVO_(4)composite particles using a simple ultrasonic blending method.The structure of the resulting composite photocatalysts was characterized via XRD,SEM,FT-IR,and UV-Vis spectra,and its photocatalytic activities in the degradation of Rhodamine B were tested.The experimental results revealed that the smaller Ni(HNCN)_(2)particles produced via ultrasonic treatment were deposited on the surface of BiVO_(4)to form a heterostructure.The bandgap of single Ni(HNCN)_(2),Bi VO_(4),and Ni(HNCN)_(2)-Bi VO_(4)are 2.64,2.41,and 2.37 e V,respectively.Compared to the single Ni(HNCN)_(2)and Bi VO_(4)particles,there was improved sensitivity to visible light in Ni(HNCN)_(2)-Bi VO_(4)composites due to the narrower bandgap of the composite particles.During the photocatalytic degradation of Rhodamine B,the composite particles synthesized with 1∶2 mole ratio of Ni(HNCN)_(2)and Bi VO_(4)demonstrated the best visible-light photocatalytic activity.The mechanism of the photocatalysis suggested that the matched band structure promotes the flow of the photogenerated electrons and holes at the interface,thereby improve the photocatalytic efficiency.