Enhanced photocatalytic activity of AgNPs-in-CNTs with hydrogen peroxide under visible light irradiation
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Silver nanoparticles in carbon nanotubes (AgNPs-in-CNTs) were prepared through a simple thermal decomposition method. Synthesized AgNPs-in-CNTs were characterized by X-ray diffraction (XRD), UV-vis diffuse reflectance spectroscopy, high-resolution transmission electron microscopy (HRTEM), and X-ray photoelectron spectroscopy (XPS). In the presence of hydrogen peroxide (H2O2), AgNPs-in-CNTs exhibited perfect photocatalytic activity in rhodamine B (RhB) degradation under visible light irradiation. Hydrogen peroxide (H2O2) concentration and initial pH values were comprehensively scrutinized. When the concentration of H2O2 was 20 mM, about 99.8% RhB (20 mg L−1) could be degraded within 50 min while the initial pH (3–10) values had a negligible effect on the degradation. From the investigations of Raman spectroscopy, transient photocurrent responses, photoluminescence, and radical quenching experiments, the findings suggest that under light irradiation, AgNPs-in-CNTs can absorb photons and generate photogenerated electrons through localized surface plasmon resonance (LSPR) effect, the photogenerated electrons react with H2O2 to produce ·OH radicals for decomposing RhB.
KeywordsAgNPs-in-CNTs Hydrogen peroxide Rhodamine B Degradation OH radicals LSPR effect
This study was supported by the National Natural Science Foundation of China (Nos. 31570568, 31670585), Science and Technology Planning Project of Guangzhou City, China (Nos. 201607010079, 201607020007), and Science and Technology Planning Project of Guangdong Province, China (Nos. 2016A020221005, 2017A040405022)