新加坡南洋理工大学Zhang Zhengyang团队报道了应变对石墨氮化碳光催化反应的影响。相关研究成果于2024年12月18日发表于国际顶尖学术期刊《美国化学会杂志》。

二维纳米材料中的应变工程在调节晶格和能带结构方面具有巨大的潜力，特别是通过局部应变，可以在特定区域进行调节。尽管局部应变的影响显著，但局部应变、光生电荷载流子的空间相关性和光催化性能之间的关系仍然难以捉摸。

该研究将单分子定位显微镜与基于坐标的共定位（CBC）分析相结合，以解释这些关系。该方法涉及绘制石墨氮化碳（g-C3N4）纳米片上光诱导氧化和还原反应位点的空间分布图，量化和空间解析它们的空间相关性，并评估它们的光催化活性。

该研究检查了65个单独的g-C3N4纳米片，揭示了颗粒间和颗粒内的异质性，这些异质性是根据其CBC评分分布进行分类的。在65 g-C3N4纳米片中，A型纳米片占主导地位（65个中有45个），并沿一些皱纹显示出相关和不相关的亚区域。相比之下，B型纳米片（65个中有20个）的主要特征是非相关亚区，相关定位最小。

非相关和相关子区域的共存推断出皱纹的结构为折叠皱纹，其拉伸应变面积比波纹皱纹大。折叠皱纹通过在拉伸应变亚区形成I型带排列来促进共定位。这种带排列还通过漏斗效应增强了光催化活性，改善了光吸收，导致相关子区域的比活性高于非相关子区域。

该研究强调了应变诱导带排列在调节光氧化还原反应的空间相关性，和亚区域水平的光催化性能方面的作用。

附：英文原文

Title: Effect of Strain on the Photocatalytic Reaction of Graphitic Carbon Nitride: Insight from Single-Molecule Localization Microscopy

Author: Jia Xin Chan, Shuyang Wu, Jinn-Kye Lee, Mingyu Ma, Zhengyang Zhang

Issue&Volume: December 18, 2024

Abstract: Strain engineering in two-dimensional nanomaterials holds significant potential for modulating the lattice and band structure, particularly through localized strain, which enables modulation at specific regions. Despite the remarkable effects of local strain, the relationships among local strain, spatial correlation of photogenerated charge carriers, and photocatalytic performance remain elusive. The current study coupled single-molecule localization microscopy with coordinate-based colocalization (CBC) analysis to explain these relationships. The methodology involved mapping the spatial distributions of photoinduced oxidation and reduction reaction sites across graphitic carbon nitride (g-C3N4) nanosheets, quantifying and spatially resolving their spatial correlation, and also evaluating their photocatalytic activity. The study examined 65 individual g-C3N4 nanosheets, revealing interparticle and intraparticle heterogeneity, which was classified based on their CBC score distributions. Among the 65 g-C3N4 nanosheets, type A nanosheets predominated (45 out of 65) and demonstrated both correlated and noncorrelated subregions along some wrinkles. In contrast, type B nanosheets (20 out of 65) were primarily characterized by noncorrelated subregions with minimal correlated localizations. The coexistence of both noncorrelated and correlated subregions inferred the structure of the wrinkles as folding wrinkles, which have larger tensile-strained areas than rippling wrinkles. Folding wrinkles promote colocalization through the formation of type I band alignment at tensile-strained subregions. This band alignment also enhances photocatalytic activity through a funneling effect and improved light absorption, leading to higher specific activity in correlated subregions compared to noncorrelated ones. The role of strain-induced band alignment in modulating the spatial correlation of the photoredox reaction and the photocatalytic performance at the subregion level is highlighted.

DOI: 10.1021/jacs.4c13707

Source: https://pubs.acs.org/doi/abs/10.1021/jacs.4c13707