On the basis of first-principles calculations, we investigated the structural and electronic properties of the two-dimensional (2D) Au-1,3,5 triethynylbenzene (Au-TEB) framework, which has been recently synthesized by homocoupling reactions in experiments. Featured by the C-Au-C linkage, the 2D Au-TEB network has a kagome lattice by Au atoms and a hexagonal lattice by organic molecules within the same metal-organic framework (MOF), which exhibits intrinsic half-metallicity with one spin channel metallic and the other spin channel fully insulating with a large energy gap of 2.8 eV. Two branches of kagome bands are located near the Fermi level, with each branch including one flat band and two Dirac bands, which originates from the out-of-plane d_xz and d_yz orbitals of Au and may lead to many exotic topological quantum phases. We further studied the adsorption of F atoms, Cl atoms, and small gas molecules including O₂, CO, NO₂, and NH₃ on the Au-TEB network, aiming to exploit its potential applications in gas sensors. Detailed analyses on adsorption geometry, energy, molecular orbital interaction, and electronic structure modification suggest the great potential of Au-TEP as a promising alternative for gas sensing. We expect these results to expand the universe of low-dimensional half-metallic MOF structures and shed new light on their practical applications in nanoelectronics/spintronics.

中文翻译：

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二维Au-1,3,5三乙炔基苯有机金属晶格：结构，半金属性和气体感测

在第一性原理计算的基础上，我们研究了二维（2D）Au-1,3,5三乙炔基苯（Au-TEB）骨架的结构和电子性质，该骨架最近通过实验中的均偶联反应合成。二维Au-TEB网络以C-Au-C键为特征，在同一金属-有机骨架（MOF）内具有一个由Au原子组成的kagome晶格和一个由有机分子组成的六边形晶格，一次旋转即可表现出固有的半金属性沟道金属和另一个自旋沟道完全绝缘，具有2.8 eV的大能隙。kagome频带的两个分支位于费米能级附近，每个分支包括一个平坦频带和两个Dirac频带，它们起源于平面外d _xz和d _yzAu的轨道，并可能导致许多奇异的拓扑量子相。我们进一步研究了Au-TEB网络上F原子，Cl原子和包括O ₂，CO，NO ₂和NH _3的小气体分子的吸附，旨在开发其在气体传感器中的潜在应用。对吸附几何结构，能量，分子轨道相互作用和电子结构修饰的详细分析表明，Au-TEP的巨大潜力可作为一种有前景的气体传感替代方法。我们希望这些结果将扩大低维半金属MOF结构的范围，并为它们在纳米电子/自旋电子学中的实际应用提供新的思路。