汞在Ti2NO2 MXene表面吸附氧化的第一性原理计算
First-principles calculation of adsorption and oxidation of mercury on the Ti2NO2 MXene surface
魏煜莹 1王军凯 1黄珍霞 2戚海新 1王向岭1
作者信息
- 1. 河南理工大学 材料科学与工程学院,焦作 454003
- 2. 河南理工大学 化学化工学院,焦作 454003
- 折叠
摘要
汞是一种有毒的重金属,在生产生活中以各种形式排放的汞对生态及人类健康都存在一定程度的威胁.因此,寻找高效的汞吸附剂具有十分重要的意义.本文基于密度泛函理论的第一性原理计算方法,研究了汞在Ti2NO2(MXene)和具有一个氧空位缺陷的Ti2NO2(Ov-Ti2NO2)上的吸附和氧化机理.计算结果表明Hg0在Ti2NO2表面的吸附为物理吸附,在Ov-Ti2NO2 表面为化学吸附.Ti2NO2 表面氧空位的存在可以改善HgO与Ov-Ti2NO2之间的相互作用,从而使吸附能提高116 kJ/mol.Hg0在Ov-Ti2NO2表面氧化为HgO的反应能垒为92.55 kJ/mol,小于其在Ti2NO2 表面氧化反应的能垒(101.42 kJ/mol),更有利于Hg0的氧化.此外,产物HgO在Ov-Ti2NO2 表面脱附需要226.18 kJ/mol能量,远高于在Ti2NO2 表面脱附所的110.49 kJ/mol,说明Ov-Ti2NO2对产物HgO的集中控制能力优于Ti2NO2,从而更能抑制HgO脱附造成二次污染.
Abstract
Mercury is a toxic heavy metal,and mercury emitted in various forms in production and life poses a certain degree of threat to ecology and human health.Therefore,it is of great importance to find highly effective mercury adsorbents.Based on the first-principles calculation method of density functional theory,the adsorp-tion and oxidation mechanism of mercury on Ti2NO2(MXene)and Ti2NO2 with an oxygen vacancy(Ov-Ti2NO2)defect was studied.The calculation results show that the adsorption of Hg0 on the surface of Ti2NO2 is phys-ical adsorption and the adsorption on the surface of Ov-Ti2NO2is chemical adsorption.The presence of oxygen vacancies on the surface of Ti2NO2 can improve the interaction between HgO and Ov-Ti2NO2,thereby increas-ing the adsorption energy by 116 kJ/mol.The reaction barrier of Hg0oxidation to HgO on the surface of Ov-Ti2NO2 is 92.55 kJ/mol,which is smaller than the energy barrier of its oxidation reaction on the surface of Ti2 NO2(101.42 kJ/mol),which is more conducive to the oxidation of Hg0.In addition,the energy required for the de-sorption of HgO on Ov-Ti2NO2 surface is 226.18 kJ/mol,which is much higher than that of 110.49 kJ/mol on Ti2NO2 surface,indicating that the Ov-Ti2NO2 has better control ability of product HgO than Ti2NO2,which can inhibit secondary pollution caused by HgO desorption.
关键词
Ti2NO2/MXene/汞/吸附/氧化/第一性原理计算Key words
Ti2NO2 MXene/Mercury/Adsorption/Oxidation/First-principles calculation引用本文复制引用
基金项目
国家自然科学基金(52102017)
河南省自然科学基金(222301420038)
河南省博士后项目启动资助(2020SZZ02)
河南省高校基本科研业务费专项资金资助(NSFRF220410)
河南省高校基本科研业务费专项资金资助(NSFRF220419)
河南理工大学博士基金(B2019-40)
出版年
2024
国家科技期刊平台
NSTL
万方数据