1D ZnFe_2O_4 nanorods coupled with plasmonic Ag, Ag_2S nanoparticles and Co-Pi cocatalysts for efficient photoelectrochemical water splitting

摘要

Improving the absorption of visible light, accelerating the separation of carries and reducing the recombination of electron-hole pairs are critical to enhance photo-electrochemical (PEC) performance of ZnFe2O4. Herein, the ZnFe2O4/Ag/Ag2S films are firstly prepared with a photocurrent density of 0.91 mA/cm(2) at 1.23 V vs. RHE, which is 9.10 times higher than that of pristine ZnFe2O4 (0.10 mA/cm(2) at 1.23 V vs. RHE). On the basis, Co-Pi cocatalyst is deposited on ZnFe2O4/Ag/Ag2S to further optimize PEC performance of ZnFe2O4, the photocurrent density of ZnFe2O4/Ag/Ag2S/Co-Pi is 1.18 mA/cm(2) at 1.23 V vs. RHE. The improved PEC performance of ZnFe2O4/Ag/Ag2S/Co-Pi films could be attributed to: (i) fast transmission of electron-hole pairs owing to 1D ZnFe2O4 NRs; (ii) surface plasmon resonance (SPR) effect of Ag nanoparticles; (iii) visible light absorption is improved by sensitization of Ag2S nanoparticles; (iv) Co-Pi cocatalyst decreases the recombination of electron-hole pairs by capturing holes. This work provides new insights for metal plasmas, sensitizers and cocatalysts synergistically modify photoanodes for efficient PEC water splitting. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.