设计二维有序原子微晶结构构建离子筛分通道

Integrated ionic sieving channels from engineering ordered monolayer two-dimensional crystallite structures

具有原子级厚度的物质选择传输固态通道可广泛应用于分离于能量转换过程.决定这种通道选择性的几个关键因素有通道的密度、高度、间距以及边界结构.然而,目前这种拥有原子级精度的微小限域通道仅限于微型二维晶体条带构建的概念原型器件中.本文报道了一种通过化学气相沉积法设计制备大面积、高有序的单层石墨烯微晶阵列结构.通过一种改进的各向异性刻蚀过程,可以大面积控制石墨烯微晶阵列的尺寸、形貌、间距以及边界结构.这种阵列结构可以作为支柱支撑起平滑的单晶石墨烯薄膜,从而构筑连续的埃米级(3.4A)通道.该通道能选择性通过水分子并阻挡水合离子的通过,在离子筛分和纳米过滤方面具有应用潜力.

Atomically thin solid-state channels enabling selective molecular transport could potentially be used in a variety of separation and energy conversion applications.The density of channels,their height,distance and edge structure are the key factors that dramatically impact the selective transport performance.However,such channels with small constrictions and atomic precision have been limited to proof-ofconcept demonstrations based on microscale two-dimensional(2D)crystal stripes.Here,we report the engineering of highly ordered,scalable monolayer graphene crystallite arrays by chemical vapor deposition(CVD)method with a modified anisotropic etching approach.The size,shape,distance and edge structure of the graphene crystallite arrays in a large area could be delicately controlled through tailoring the synthetic parameters.This array structure can act as pillars to prop up a smooth single-crystal graphene film,and the fabricated integrated angstrom-size(3.4A)channels allow water transport but exclude hydrated ions,demonstrating potential in selective ionic sieving and nanofiltration practice.