近日，大连民族大学张振翼团队研究了优化AuAg合金修饰TiO₂纳米纤维中的Schottky势垒以增强热电子诱导CO₂还原。这一研究成果于2025年6月9日发表在《结构化学》杂志上。

等离子体诱导的热电子可以从贵金属转移到其异质结构中的内聚半导体，在共振激发下启动光催化反应。然而，异质结构中半导体的共激发也会导致光电从半导体到贵金属的反向转移，这不可避免地限制了活性电子的使用。研究组证明，在贵金属的局域表面等离子体共振（LSPR）和半导体的带间跃迁共同激发后，界面电子转移过程强烈依赖于其异质结构的能带结构。 

当AuAg合金纳米颗粒（NP）中的Au含量从0变为100原子%时，电纺纳米纤维（NF）中AuAg NPs/TiO₂ NPs处的界面能带结构从欧姆接触转变为肖特基接触。进一步的研究发现，Au_0.25Ag_0.75/TiO₂ NF中的最佳肖特基势垒配置不仅可以促进等离子体激元诱导的热电子从Au_0.25Ag_0.75转移到TiO₂ NP，还可以抑制NF中光电从TiO₂回流到Au_0.25Ag_0.75NP。因此，在紫外-可见光照射下，Au_0.25Ag_0.75/TiO₂ NF的CO₂光还原活性比Ag/TiO₂或Au/TiO₂ NF高出3倍和2倍。

附：英文原文

Title: Optimizing the Schottky barrier in AuAg alloy decorated TiO2 nanofibers to enhance hot-electron-induced CO2 reduction

Author: anonymous

Issue&Volume: 2025-06-09

Abstract: Plasmon-induced hot electron can transfer from noble metal to its cohesive semiconductor in their heterostructure to initial the photocatalytic reaction upon resonance excitation. However, the co-excitation of semiconductor in the heterostructure would also lead to the inversus transfer of photo-electron from semiconductor to noble metal, which inevitably limits the use of active electrons. Herein, we demonstrate that after co-excitation of both the localized surface plasmon resonance (LSPR) of noble metal and the interband transition of semiconductor, the interfacial electron transfer process strongly depends on the energy band configuration of their heterostructure. When the Au content in the AuAg alloy nanoparticles (NPs) was changed from 0 to 100 at.%, the interfacial energy band configuration at AuAg NPs/TiO2 NPs in the electrospun nanofibers (NFs) shifted from Ohmic to Schottky contacts. Further investigation found that the optimal Schottky barrier configuration in the Au0.25Ag0.75/TiO2 NFs can not only boost the plasmon-induced hot electron transfer from Au0.25Ag0.75 to TiO2 NPs but also suppresses the backflow of photo-electrons from TiO2 to Au0.25Ag0.75 NPs in the NFs. Thus, upon UV-visible light irradiation, the CO2 photo-reduction activity of the Au0.25Ag0.75/TiO2 NFs was ～3 and ～2 times higher than that of either Ag/TiO2 or Au/TiO2 NFs.

DOI: 10.1016/j.cjsc.2025.100633

Source: https://cjsc.ac.cn/cms/issues/814