Enhancement of Photoelectrochemical Performance of Ag@ZnO Nanowires: Experiment and Mechanism

Abstract

This paper focuses on the enhancement of photoelectrochemical (PEC) performance of uniform silver nanoparticles-decorated ZnO (Ag@ZnO) nanowires, which have been synthesized by two-step chemical vapor deposition to prepare ZnO nanowires then magnetron sputtering method to deposit Ag nanoparticles. Moreover, we analyzed the mechanisms of the PEC behavior of the Ag@ZnO nanowires. The PEC characteristics show that the current density of Ag@ZnO nanowires increased comparing to that of unmodified ZnO nanowires. The optimized content of the Ag-decorated ZnO photoelectrode is up to the maximum photocurrent density of 24.8 μAcm-2 at 1 V vs. Ag/AgCl, which was almost four times than that of the unmodified ZnO photoelectrode. Based on the surface plasmon resonance (SPR), effect of Ag nanoparticles was enhanced PEC performance of the Ag@ZnO nanowires. Because SPR effect of Ag nanoparticles extended the light absorption and enhanced the separation efficiency of the photogenerated electron-hole pairs. The remarkable PEC properties offer metals-semiconductor compound nanostructures materials as a promising electron source for high current density applications.

UV-Induced Room-Temperature Ethylene Sensors Based on Ag-Decorated ZnO Nanoflowers for Fruit Ripeness Monitoring

“…In contrast, when Ag NPs are decorated on the surface of ZnO NFs, the formation of extended depletion layer can significantly enhance the gas sensing response of ZnO. Furthermore, under UV illumination, Ag NPs can induce LSPR, promoting the generation and dissociation of electron–hole pairs in ZnO. , This leads to an enhancement in the photocurrent-to-dark current efficiency of the composite. Moreover, due to LSPR, hot electrons can be transferred to the conduction band of ZnO, improving the reaction of the gas sensors .…”

“…Furthermore, under UV illumination, Ag NPs can induce LSPR, promoting the generation and dissociation of electron− hole pairs in ZnO. 48,49 This leads to an enhancement in the photocurrent-to-dark current efficiency of the composite. Moreover, due to LSPR, hot electrons can be transferred to the conduction band of ZnO, improving the reaction of the gas sensors.…”

The impact of electrolytic pH on photoelectrochemical water oxidation

“…Previous studies on ZnO-based PEC systems have focused on nanostructuring, metal or non-metal doping, heterojunctions, surface modication with plasmon modication, quantum dot modication, etc. [24][25][26][27][28] Nitrogen incorporation in ZnO reduces the optical band gap and improves absorption in the solar spectrum for better PEC efficiency. [29][30][31][32][33][34][35][36][37] However, the effect of pH on electrolytes and their effect on PEC activity have not been reported.…”