二维Ti3C2/MoS2异质结复合材料光催化氧化烟气中单质汞的DFT计算OA

Photocatalytic technology provides an efficient approach for the remediation of environmental heavy metal pollution.Among these,photocatalytic mercury removal has garnered significant attention due to its ability to efficiently convert toxic elemental mercury(Hg0)into more readily removable mercury species,offering notable environmental and economic benefits.However,the low quantum efficiency caused by the facile recombination of photogenerated carriers remains a key scientific challenge hindering its practical application.To overcome this bottleneck,this study employed density functional theory(DFT)calculations to investigate the reaction mechanism of mercury removal from flue gas using a two-dimensional Ti3C2/MoS2 heterojunction composite material.The calculation results indicate that the adsorption energy of Hg0 on the Ti3C2(001)surface is significantly more negative than that on a monolayer of MoS2,with a most negative adsorption energy of-1.067 eV,confirming the presence of preferential adsorption sites on the Ti3C2 surface.The constructed 2D/2D Ti3C2/MoS2 heterojunction effectively modulates the band structure through the formation of a built-in electric field,thereby greatly enhancing the directional separation and transfer efficiency of photogenerated charge carriers.Furthermore,the construction of the heterojunction significantly reduces the energy barrier of the rate-determining step(from 1.102 eV to 0.99 eV).This study reveals the microscopic mechanism behind the highly efficient mercury removal by this heterojunction at the atomic scale,providing an important theoretical basis and design strategy for high-performance modified composite photocatalysts.