Open AccessRealization of electrolyte interface effect on Bi2Te3 implanted flake-like ZnO thin films for understanding the highly stable PEC water splitting under simulated solar light and visible light
Author(s) -
Adem Sreedhar,
JinSeo Noh
Publication year - 2021
Publication title -
materials research express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.383
H-Index - 35
ISSN - 2053-1591
DOI - 10.1088/2053-1591/abd787
Subject(s) - electrolyte , materials science , visible spectrum , thin film , water splitting , sputter deposition , ion , optoelectronics , sputtering , chemical engineering , nanotechnology , photocatalysis , electrode , chemistry , biochemistry , engineering , catalysis , organic chemistry
This study aimed to rationally design the novel Bi 2 Te 3 implanted ZnO (Bi 2 Te 3 @ZnO) thin films using simultaneous RF and DC magnetron sputtering technique. Herein, we explored the electrolyte interface effect (0.1 M of KOH, KCl, Na 2 SO 3 and Na 2 SO 4 ) on ZnO and Bi 2 Te 3 @ZnO towards highly stable PEC water splitting activity for the first time. Specifically, morphological evolution and electrolyte ion diffusion properties play a crucial role in realizing the prolonged charge carrier lifetime. Moreover, Bi 2 Te 3 @ZnO is highlighted with unique nanocone-shaped morphology compared to flake-like ZnO. Also, constructive interfacial interaction was observed between Bi 2 Te 3 and ZnO. As a result, Bi 2 Te 3 @ZnO demonstrated superior and highly stable photocurrents in the KOH electrolyte compared to KCl, Na 2 SO 3 and Na 2 SO 4 electrolytes. Precisely, Bi 2 Te 3 @ZnO triumphed highly stable photocurrents about 7.93 × 10 –4 A cm −2 compared to ZnO (6.02 × 10 –4 ) at +0.4 V under solar light in KOH electrolyte. Accordingly, Bi 2 Te 3 @ZnO achieved remarkable photoconversion efficiency ( η ) about 0.65 %, which is enabled by the strengthened intimate interaction between Bi 2 Te 3 and ZnO. Furthermore, we compared the PEC activity under visible light (UV cut-off solar light). These results highlighted that the photoconversion efficiency difference between Bi 2 Te 3 @ZnO and ZnO (about 4 times) under visible light is relatively higher than solar light (1.3 times) in KOH. Thus, we proposed different charge carrier generation mechanisms of Bi 2 Te 3 @ZnO under solar and visible light. Therefore, intimate interfacial interaction, surface modification, ion diffusion and photoelectrode-electrolyte interaction are key parameters to enhance the PEC activity. Overall, rational design of the transition metal oxide/thermoelectric material interface using Bi 2 Te 3 @ZnO composite paves a new path towards highly stable photoanode during PEC water splitting activity in the KOH electrolyte environment.