Plasmonic MoO3-x nanosheets with tunable oxygen vacancies as efficient visible light responsive photocatalyst

Abstract

Localized surface plasmon resonance applied in catalytic and optical field has attracted more attentions in recent years. Plasmonic MoO 3-x nanosheets with tunable oxygen vacancies were constructed via facile solvothermal method. The as-prepared MoO 3-x nanosheets were found to have LSPR absorption band centered at 680 nm, and exhibited excellent photocatalytic performance in photodegradation of organic dyes and tetracycline under visible light irradiation. X-ray photoelectron spectroscopy showed the higher content of surface oxygen vacancies in MoO 3-x (88 mmol). Photocurrent, electrochemical impedance spectroscopy and photoluminescence results demonstrated that MoO 3-x (88 mmol) exhibits the best photo-induced electron hole separation efficiency and the highest charge transfer efficiency. Taken together, oxygen vacancies are not only responsible for the light harvesting in the visible and near-infrared region via LSPR, but also play a key role in greatly suppressing the recombination of photoexcited carriers. Moreover, electron paramagnetic resonance revealed that photoinduced h + and ·OH radicals act as the main reactive species participating in the photoxidation process. • Plasmonic MoO 3-x nanosheets with tunable oxygen vacancies were obtained. • LSPR effect results in MoO 3-x nanosheets with light adsorption in visible and near-infrared region. • MoO 3-x nanosheets show superior photodegradation efficiency on organic dyes and tetracycline. • Oxygen vacancies play a key role in greatly suppressing the recombination of photoexcited carriers. • OH radicals act as the main reactive species participating in the photoxidation process.