Plasmon‐Enhanced Charge Separation and Surface Reactions Based on Ag‐Loaded Transition‐Metal Hydroxide for Photoelectrochemical Water Oxidation

• Published in: Advanced energy materials 2021-05, Vol.11 (17), p.n/a
• Main Authors: Ning, Xingming, Yin, Dan, Fan, Yiping, Zhang, Qi, Du, Peiyao, Zhang, Dongxu, Chen, Jing, Lu, Xiaoquan
• Format: Article
• Language: English
• Subjects: Bismuth oxides; Catalysis; charge separation; Charge transfer; Cobalt; Hydroxides; Metal hydroxides; Nanoparticles; Oxidation; Oxygen evolution reactions; Photoelectric effect; Photoelectric emission; photoelectrochemical; Separation; Silver; Solar energy conversion; surface plasmon resonance; Surface reactions; transition‐metal hydroxide; Vanadates; Water splitting
• ISSN: 1614-6832; 1614-6840
• DOI: 10.1002/aenm.202100405

Coating photoanodes with transition‐metal hydroxides (TMH) is a promising approach for improving photoelectrochemical (PEC) water oxidation. However, the present system still suffers from high charge recombination and sluggish surface reactions. Herein, effective charge separation is achieved at the same time as boosting the surface catalytic reaction for PEC water splitting through decoration of plasmon metal (Ag) in a semiconductor/TMH coupling system. The kinetic behavior at the semiconductor/TMH and TMH/electrolyte interfaces is systematically evaluated by employing intensity modulated photocurrent spectroscopy, scanning photoelectrochemical microscopy, and oxygen evolution reaction model. It is found that both charge transfer and surface catalysis dynamics are enhanced through local surface plasmon resonance of Ag nanoparticles. The as‐prepared BiVO4/Co(OH)x‐Ag exhibits remarkable activity (≈4.64 times) in PEC water splitting in comparison with pure BiVO4. Notably, this smart approach can be also applied to other TMH (Ni(OH)2), reflecting its universality. This work provides a guiding design method for solar energy conversion with the semiconductor‐TMH system. Fast charge recombination and sluggish oxygen evolution reactions lead to the low photoelectrochemical (PEC) water splitting efficiency. Ag nanoparticles can act as an interfacial accelerator, to simultaneously boost interfacial charge transfer and surface catalytic via the activity local surface plasmon resonance of Ag. This strategy can markedly increase the PEC performance (BV/Co(OH)x‐Ag), achieving a 4.64‐fold enhanced activity compared to BiVO4 (BV).