尿素改性Bi_(2)MoO_(6)摩擦催化氧化降解罗丹明B

Urea-modified Bi_(2)MoO_(6)friction-catalyzed oxidative degradation of rhodamine B

通过水热法制备了尿素改性Bi_(2)MoO_(6)(Urea-Bi_(2)MoO_(6))催化剂,借助SEM,XRD,XPS,BET等技术表征了其微观结构.经过尿素改性的Bi_(2)MoO_(6)结晶度提高,具有优异的摩擦催化性能.在转速为700r/min,RhB浓度为5mg/L,催化剂投加量为1g/L,35mm PTFE磁子的条件下,反应300min,RhB的降解率达99.02%.Urea-Bi_(2)MoO_(6)摩擦催化氧化降解RhB符合一级反应动力学方程.Urea-Bi_(2)MoO_(6)循环利用5次以后,RhB降解率仍在91.6%以上.EPR证实Urea-Bi_(2)MoO_(6)摩擦催化过程中产生了h^(+)·,O_(2)^(-)和·OH自由基,自由基猝灭实验证实h^(+)是导致RhB降解的主要物质,Urea-Bi_(2)MoO_(6)受到摩擦刺激,产生电子(e-)-空穴(h^(+))对.h^(+)与游离的OH^(-)反应生成·OH,e^(-)与水中的O_(2)生成·O_(2)^(-),三者协同降解RhB.

Urea modified Bi_(2)MoO_(6)(Urea-Bi_(2)MoO_(6))catalyst was prepared by a hydrothermal method,and its microstructure was characterized by SEM,XRD,XPS,BET,etc.The crystallinity of Bi_(2)MoO_(6)modified by urea was improved,and it exhibited excellent frictional catalytic performance.Under the conditions of a rotational speed of 700r/min,RhB initial concentration of 5mg/L,catalyst dosage of 1g/L,and 35mm PTFE magnetic particles,the degradation of RhB reached 99.02%after 300min.The friction catalyzed oxidation degradation of RhB by Urea-Bi_(2)MoO_(6)followed first-order reaction kinetics equation After 5cycles of Urea-Bi_(2)MoO_(6)friction catalysis,RhB degradation remained above 91.6%.EPR confirmed that h^(+),·O_(2)^(-),and·OH radicals were generated during the friction catalytic process of Urea Bi_(2)MoO_(6).And scavenger test for radicals confirmed that h^(+)was the main substance causing RhB to be degraded.Urea-Bi_(2)MoO_(6)is stimulated by friction,producing electron(e-)-hole(h^(+))pairs.H^(+)reacts with OH^(-)to generate·OH,and e-reacts with O_(2)in water to generate·O_(2)^(-),then RhB is degraded by them.