摘要
以Bi(NO3)3.5H2O、NH4VO3和Ni(NO3)2.6H2O为原料,采用水热法合成了Ni-BiVO4光催化剂,并利用XRD、SEM、XPS、Raman、UV-Vis DRS等测试手段对产品进行表征和分析,探讨不同pH值对BiVO4颗粒晶相与形貌的影响。以亚甲基蓝作为模型污染物考察Ni-BiVO4催化剂的光催化性能。结果表明,提高前驱液pH值,可得到单斜晶系白钨矿型Ni-BiVO4光催化剂。光催化剂中的Ni元素以NiO形式存在。Ni的引入使可见光吸收带发生红移,能带隙减小至2.35 eV。可见光催化降解亚甲基蓝溶液的结果表明,Ni掺杂有利于提高BiVO4的活性。其中pH值为5.0、Ni掺杂量为2.0wt%的BiVO4具有最好的光催化效果,可见光照射120 min后,对初始浓度为10 mg/L的亚甲基蓝溶液的最高降解率由纯BiVO4的77%提高到99.45%。并对Ni引入后光催化活性提高的机理进行了分析。
Ni-BiVO4 photocatalysts were prepared by hydrothermal method using Bi(NO3)3.5H2O,NH4VO3 and Ni(NO3)2.6H2O as raw materials.The as-prepared BiVO4 samples were characterized by XRD,SEM,XPS,Raman and UV-Vis DRS.The effect of pH values on the phase and morphology of samples were studied.The photocatalytic activity of the Ni-BiVO4 powders was determined by degradation of methylene blue(MB) molecules in water under visible light irradiation.The results showed that highly crystalline monoclinic scheelite structure of Ni-BiVO4 could be obtained through increasing the pH value.The XPS results revealed that the doped Ni species exists in the form of NiO.Compared with pure BiVO4,the Ni-BiVO4 catalyst has a red-shift in the absorption band in the visible region and its narrowed band gap(2.35 eV).The Ni-BiVO4 photocatalysts enhanced photocatalytic activities for degradation of methylene blue(MB) under visible light irradiation.When pH value was 5.0 and Ni content 2.0 wt%,the photocatalytic activities reached the maximum.After visible light irradiation for 120 min,the removal rate of MB byNi-BiVO4(2.0wt% Ni) at 10 mg/L initial concentration increases to 99.45% while the removal rate of MB by pure BiVO4 is only 77%.The mechanism of enhanced photocatalytic activity has been discussed.
出处
《人工晶体学报》
EI
CAS
CSCD
北大核心
2013年第6期1230-1236,1246,共8页
Journal of Synthetic Crystals
基金
广西理工科学实验中心资助项目(LGZXKF201111)
作者简介
陈渊（1971-），女，广西壮族自治区人，教授，硕士。E-mail：chenyuanl97191@163．com
通讯作者：周科朝，教授，博士。E—mail：zhoukechao@mail．CSU．edu．cn
