Photocatalytic degradation of dye by Ag/TiO2 nanoparticles prepared with different sol–gel crystallization in the presence of effluent organic matter
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TiO2 nanoparticle-doped Ag (Ag/TNPs) have good photocatalytic properties based on localized surface plasmon resonance (LSPR) effect. The effluent organic matter (EfOM) can be easily activated by photo-excitation to promote pollutant photodegradation, but excessive EfOM has an inactive effect. Herein, the purpose of this paper is to investigate the changes of photocatalytic performance by Ag/TNPs in the presence of EfOM. Three Ag/TNPs made by condensation crystallization or rotary evaporation crystallization using the sol–gel method were conducted in photocatalytic degradation of methyl orange (MO). The Ag/TNPs crystallized by condensation had greater separation rate of photogenerated electron–hole pairs and photocatalytic degradation of MO with high load rates of binding Ag and TiO2 than those formed by rotary evaporation crystallization. Indeed, EfOM could be excited to produce the active substances under illumination resulting in the promotion of MO degradation. However, contrary to previous speculation, no additive effect of MO photodegradation was observed with the addition both of EfOM and Ag/TNPs at different pH values (5~9) and ion strength (0~0.4 mol L−1). It can be explained that the EfOM changed the morphology and active sites in Ag/TNPs’ surface. Meanwhile, EfOM could be consumed and degraded by Ag/TNP photocatalysis leading to the concentration of free radicals to decrease. This study revealed a nonsynergistic effect between nanomaterial and EfOM for photocatalysis. EfOM would have a negative effect on photocatalytic degradation of organic compounds by Ag/TNPs in the aquatic environment.
KeywordsEffluent organic matter Photocatalytic degradation Titanium dioxide Silver Water treatment Methyl orange
The research was sponsored by China’s National Natural Science Foundation (grants 51878321, 21866017, and 41761092), by the Applied Fundamental Research Foundation of Yunnan Province (grant 2018FA007), and by the China Scholarship Council Fund (project 201808530511).
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Conflict of interest
The authors declare that they have no conflicts of interest.
- Guillén-Santiago A, Mayén SA, Torres-Delgado G, Castanedo-Pérez R, Maldonado A, Olvera MDLL (2010) Photocatalytic degradation of methylene blue using undoped and Ag-doped TiO2 thin films deposited by a sol–gel process: effect of the ageing time of the starting solution and the film thickness. Mater Sci Eng B-Adv: B 174:84–87CrossRefGoogle Scholar
- Mojgan G, Fatemeh A, Salavati-Niasari M (2016) Simple synthesis-controlled fabrication of thallium cadmium iodide nanostructures via a novel route and photocatalytic investigation in degradation of toxic dyes. Inorg Chim Acta 455:88–97Google Scholar