摘要
采用简单的化学浴沉积法(CBD)制备出水合氢氧化镍[Ni(OH)_(2)·0.75H_(2)O]粉体。该粉体具有微/纳构造特征,整体呈现出无规则微米级颗粒状形貌,由纳米片自组装而成。考察了水合氢氧化镍作为催化剂活化单过硫酸氢钾(PMS)降解亚甲基蓝(MB)溶液的性能。结果表明,Ni(OH)_(2)·0.75H_(2)O/PMS复合体系具有良好的降解MB溶液的能力,其对MB的降解率可达84.33%;而相同条件下Ni(OH)_(2)·0.75H_(2)O或PMS单一体系对MB的降解率仅为9.46%和21.19%。MB溶液的降解率随反应体系中PMS用量的增加而提高,随MB初始浓度的增加而降低,随催化剂用量的增加先增加而后维持不变。Ni(OH)_(2)/PMS体系中引入C_(2)O_(4)^(2-)或PO_(4)^(3-)阴离子会抑制MB溶液的降解,抑制率分别为65.77%和16.44%,但NO_(3)-的引入对MB的降解无抑制。自由基俘获结果证实,·SO_(4)-是参与直接氧化降解MB的主要活性中间体;动力学分析表明氢氧化镍催化活化PMS降解MB溶液的反应为二级反应,其表观反应速率常数k=5.39 L/(mmol·min)。
Powder nickel hydroxide hydrate(Ni(OH)_(2)·0.75H_(2)O)was successfully prepared by a simple chemical bath deposition(CBD)method.The sample exhibited a micro/nano hierarchical structure.Namely,these powders presented irregular granule appearance with micron-size,which were actually made up of many nano-flakes.The performance of powdered nickel hydroxide hydrate used as catalyst for decomposition of methylene blue(MB)in aqueous solution with potassium monopersulfate(PMS)was investigated.The results showed that the Ni(OH)_(2)·0.75H_(2)O/PMS composite system had an outstanding catalytic ability in MB degrading.The degradation rate of MB was 84.33%.Under the same conditions,the degradation rates of MB by Ni(OH)_(2)·0.75H_(2)O or PMS were only 9.46%and 21.19%,respectively.The degradation rate of MB solution increased with the increase of the amount of PMS in the reaction system and decreased with the increase of the initial concentration of MB,which also increased firstly and then remained unchanged with the increase of the amount of catalyst.The introduction of C_(2)O_(4)^(2-)或PO_(4)^(3-)anion into Ni(OH)_(2)/PMS system could inhibit the degradation of MB solution,and the inhibition rates were 65.77%and 16.44%,respectively,but the introduction of NO_(3)-had no inhibition on the degradation of MB.The results of free radical capture confirmed that·SO_(4)-was the main active intermediate involved in the direct oxidative degradation of MB.Kinetic analysis showed that the degradation of MB solution by PMS catalyzed by nickel hydroxide was a second-order reaction,and its apparent reaction rate constant k=5.39 L/(mmol·min).
作者
夏强
廖小刚
李纲
Xia Qiang;Liao Xiaogang;Li Gang(College of Chemistry and Chemical Engineering,Chongqing University of Technology,Chongqing 400054,China)
出处
《无机盐工业》
CAS
CSCD
北大核心
2021年第10期119-124,共6页
Inorganic Chemicals Industry
基金
重庆市教委科学技术研究重点项目(KJZD-K201801103)
重庆市科技局技术创新与应用发展专项面上项目(cstc2019jscx-msxmX0358)
重庆理工大学校级项目(KLA20031)。
关键词
化学浴沉积法
氢氧化镍
单过硫酸氢钾
催化降解
亚甲基蓝
chemical bath deposition method
nickel hydroxide
potassium monopersulfate
catalytic degradation
methylene blue
