复旦大学赵东元团队报道了用单胶束定向组装亚10nm瓦楞二氧化钛纳米线阵列进行高效孔萃取。相关研究成果发表在2022年10月25日出版的《美国化学会杂志》。

催化去乙酰化是一种理想的合成策略，因为它在形式上精确地合成具有可调活性表面的有序超薄纳米线阵列，尽管在光电子学中很有吸引力，但迄今为止仍然具有挑战性。

该文中，研究人员通过独特的单胶束定向组装方法，合成了具有可控波纹结构的良好排列的亚10nm TiO₂纳米线阵列。直径非常小的约8 nm的纳米线以相同的约10nm相邻距离并排生长，形成垂直排列的阵列（～800 nm厚度），表面积为～102 m² g^–1。波纹结构由碗状凹形结构（直径～5 nm）组成，这些结构沿超薄纳米线的轴线紧密排列。通过简单地改变反应时间，凹形结构的直径可以在～2～5nm范围内进行精细控制。

该阵列显示出优异的电荷动态特性，即使在极低的0.41VRHE电位下，也能获得高达1.4%的外加偏置光子-电流效率，在1.23 VRHE下，光电流为1.96 mA cm^–2。值得注意的是，该文首次阐明了凹壁的孔提取效应的基本机理，证明了凹壁作为有效水分离的孔收集中心的确切作用。

附：英文原文

Title: Sub-10 nm Corrugated TiO2 Nanowire Arrays by Monomicelle-Directed Assembly for Efficient Hole Extraction

Author: Pengfei Zhang, Zhangliu Tian, Yikun Kang, Bowen He, Zaiwang Zhao, Chin-Te Hung, Linlin Duan, Wei Chen, Yun Tang, Jiaguo Yu, Liqiang Mai, Ye-Fei Li, Wei Li, Dongyuan Zhao

Issue&Volume: October 25, 2022

Abstract: Precise synthesis of well-ordered ultrathin nanowire arrays with tunable active surface, though attractive in optoelectronics, remains challenging to date. Herein, well-aligned sub-10 nm TiO2 nanowire arrays with controllable corrugated structure have been synthesized by a unique monomicelle-directed assembly method. The nanowires with an exceptionally small diameter of ～8 nm abreast grow with an identical adjacent distance of ～10 nm, forming vertically aligned arrays (～800 nm thickness) with a large surface area of ～102 m2 g–1. The corrugated structure consists of bowl-like concave structures (～5 nm diameter) that are closely arranged along the axis of the ultrathin nanowires. And the diameter of the concave structures can be finely manipulated from ～2 to 5 nm by simply varying the reaction time. The arrays exhibit excellent charge dynamic properties, leading to a high applied bias photon-to-current efficiency up to 1.4% even at a very low potential of 0.41 VRHE and a superior photocurrent of 1.96 mA cm–2 at 1.23 VRHE. Notably, an underlying mechanism of the hole extraction effect for concave walls is first clarified, demonstrating the exact role of concave walls as the hole collection centers for efficient water splitting.

DOI: 10.1021/jacs.2c10395

Source: https://pubs.acs.org/doi/10.1021/jacs.2c10395