等离激元纳米海胆结构增强热载流子的产生与注入  

Plasmonic Nanourchin Enhanced Hot Carrier Generation and Injection

作　　者：王茜 梁红艳 Wang Xi;Liang Hongyan(School of Materials Science and Engineering,Tianjin University,Tianjin 300350,China;Key Laboratory of Efficient Utilization of Low and Medium Grade Energy,Ministry of Education,Tianjin University,Tianjin 300350,China)

机构地区：[1]天津大学材料科学与工程学院,天津300350 [2]天津大学中低温热能高效利用教育部重点实验室,天津300350

出　　处：《中国激光》2023年第1期204-211,共8页Chinese Journal of Lasers

基　　金：国家自然科学基金(51771132)。

摘　　要：等离激元激发产生的热载流子可以有效驱动化学反应的发生,进而实现太阳能的高效利用。合理设计等离激元金属纳米结构是提高热载流子产生与注入效率,进而实现超宽光谱吸收和高效能量转换的有效途径。本课题组制备了具有高密度尖端的等离激元纳米海胆颗粒,并构建了金属半导体复合结构的光阳极,通过测试光阳极微反应区的光电流响应评估了热载流子的产生与注入效率。结果表明:纳米海胆结构具有优异的光电催化活性,其尖端处的大量热点促进了热载流子的产生,金属与半导体间丰富的界面接触增加了热载流子的注入机会。该设计为热载流子的高效激发与提取提供了参考。Objective Hot carriers induced by surface plasmon excitation can trigger chemical reactions,realizing efficient utilization of solar energy.The rational design of plasmonic metal nanostructures is considered an effective strategy for improving the efficiency of hot carrier generation and injection for ultrabroadband light absorption and efficient energy conversion.In this study,plasmonic nanourchins(NUs)with high-density tips were synthesized,and plasmonicsemiconductor nanoarchitectures were constructed as photoanodes.The photocurrent response in the microscale reaction region on the photoanode was used to evaluate the hot carrier generation and injection efficiency.The excellent performance of plasmonic NUs is ascribed to the multiple hot spots between the spikes,boosting the generation efficiency of the hot carrier,and the abundant interface between the metal and semiconductor increases the hot carrier injection opportunities.These results may pave the way for efficient excitation and extraction of hot carriers.Methods In this study,NUs with ultrahigh-density sharp tips were synthesized through a seed-mediated growth route using L-Dopa as a reduction agent.Nanocrystalline TiO_(2)thin films were prepared using sol-gel and spin-coating methods.Then,the metal-semiconductor nanoarchitecture was constructed using a simple drop-casting method as a photoanode for photoelectrochemical(PEC)reactions.Subsequently,the photocurrent response in the microscale reaction region of the photoanode was measured in a homemade PEC cell to assess the transfer efficiency of the hot carrier.The photocurrenttime curves were measured under periodically switched laser illumination by focusing a 514 nm laser with a micrometersized light spot closely on the sample particles through a water immersion objective.In addition,photocurrent measurements at different applied biases and excitation source powers were performed for the prepared NU-TiO_(2)samples to investigate other factors affecting the hot carrier generation and injection efficienc

关 键 词：材料 纳米海胆结构 热载流子 表面等离激元 等离激元光催化 

分 类 号：O643.3[理学—物理化学]