Electric Field-Induced\nEnhanced Raman Spectroscopy\nSensor and Photocatalysis with Thermoelectric–Plasmonic Metal\nNanocomposites

Electric field-induced surface-enhanced Raman scattering\n(E-SERS)\nsubstrates have been proven to further enhance the attained Raman\nintensity. Herein, integrated with plasmonic Ag nanoparticles (Ag\nNPs), the thermoelectric Bi<sub>2</sub>Te<sub>3</sub> plate as an\nE-SERS substrate decreased the limit of detection by 2 orders of magnitude\nand increased the SERS signal by >20 times compared to those without\nelectrical field induction. The thermoelectric potential produced\nby the Bi<sub>2</sub>Te<sub>3</sub> plate could modulate the electron\ndensity and subsequently change the Fermi level of Ag. This increases\nthe resonant electron transition probability using a broad range of\nmolecules. The plasmon-activated catalytic reactions of the interconversion\nbetween <i>p</i>-nitrothiophenol and <i>p</i>,<i>p</i>′-dimercaptoazobenzene could be controlled through\nthe E-SERS template. On the basis of the finite element method, explicit\ntheoretical analysis indicated that the Ag NP–Bi<sub>2</sub>Te<sub>3</sub>–molecule charge transfer could improve our\nunderstanding of the SERS and photocatalytic mechanism.