g-C_3N_4/TiO_2复合光催化剂的制备及酸化改性  

PREPARATION AND ACIDIFICATION OF g-C_3N_4/TiO_2 COMPOSITE CATALYST

作　　者：张文博 邓德明[1] ZHANG Wen-bo;DENG De-ming(School of Resource and Environmental Sciences, Wuhan University, Wuhan 430072, Chin)

机构地区：[1]武汉大学资源与环境科学学院,武汉430072

出　　处：《环境工程》2018年第4期66-71,共6页Environmental Engineering

基　　金："十二五"国家科技支撑计划(2012BAJ21B06);生物质资源化学与环境生物技术湖北省重点实验室(武汉大学)资助

摘　　要：以偏钛酸和三聚氰胺为原料,经煅烧制备g-C_3N_4/TiO_2复合纳米光催化剂,研究不同原料配比、煅烧温度和升温速率等制备条件对其可见光催化性能的影响,并采用UV-Vis DRS、FT-IR、XRD、TEM和PL等方法对催化剂进行表征。在可见光条件下,用制备的复合催化剂降解亚甲基蓝,考察了催化剂酸化改性处理对亚甲基蓝光降解效率的影响。结果表明:当m(偏钛酸)∶m(三聚氰胺)为1∶4、煅烧温度为500℃、升温速率为10℃/min时,g-C_3N_4/TiO_2复合纳米材料对20 mg/L亚甲基蓝的可见光降解效率最高,其3 h时降解率可达99.64%。经酸化改性处理后的催化剂,其电子空穴复合率被有效降低,光催化性能得到提高。此外,光催化机理的研究表明,·O_2^-是降解过程中起主要作用的活性物质。Metatitanic acid and melamine were used as raw materials for the preparation of g-C_3N_4/TiO_2 composite nanocatalyst,and the effect of proportion of each raw material,calcination temperature and heating rate on the catalyst＇s photocatalytic performance under visible light were studied. Characterization of the catalysts was conducted by XRD,TEM,FT-IR,UV-Vis DRS and PL. The composite catalysts were used to degrade methylene blue under visible light for studying the effect of catalyst＇s acidification on its performance. The results demonstrated that the degradation rate of methylene blue reach to 99. 64% at 3 h when the proportion of metatitanic acid and melamine was 1/4,calcination temperature was 500 ℃ and heating rate was 10 ℃/min,while the catalyst＇s photocatalytic performance was optimized with the reduction of recombination of its electron and hole when catalysts were acidized. Moreover,·O_2^- was proved to be the key substance in the degradation.

关 键 词：g-C3N4/TiO2 亚甲基蓝 酸化改性处理 光催化 ·O2^- 

分 类 号：O643.36[理学—物理化学]