The Photocatalytic Degradation Of Nitro-phenol By B-N-Er-TiO₂ And F-N-Er-TiO₂ Nanocrystal Under Visible Light

Different types of heterogeneous catalysts in the degradation of organic pollutants has been widely investigated and applied, in which TiO₂ play a much larger role, mainly because it is easy to be prepared, inexpensive, chemically stable, environmentally friendly, catalytic efficiency advantages. However, due to the wide band gap of TiO₂ Eg = 3 .2 eV, it can only absorb UV light, which greatly limits the photocatalytic application of TiO₂. In this paper, nano-titanium dioxide doped by rare earth ions and non-metallic elements B, N, F, has been synthesized. Through the upconversion luminescence properties of rare earth ion, change the visible light into ultraviolet light to achieve the purpose of using visible light degradation of organic pollutants by TiO₂. Specific work in the following areas:1. B(2%)-N(43%)-Er³⁺(10%)- TiO₂ and F(2.5%)-N(43%)-Er³⁺(10%)- TiO₂ mesoporous materials were prepared by the sol-gel method.2. The synthesized TiO₂ characterized by XRD, UV-Vis, BET, SEM, and upconversion luminescence spectra, after the characterization results were discussed in detail.3. The photocatalytic degradation of nitrophenol solution under visible light by B(2%)-N(43%)-Er³⁺(10%)- TiO₂ and F(2.5%)-N(43%)-Er³⁺(10%)- TiO₂ were systematic studied, including the effect of different calcination temperature (600°С, 700°С, 800°С, 900°С), the doping amount of non-metallic elements in catalyst, the initial p-nitrophenol solution concentration and different pH. And exploring the mechanism of mesoporous formation, upconversion mechanism and energy absorption,transfer on the surface of titanium dioxide in photocatalytic degradation process.4. Comparing the B (2%)-N (43%)-Er3 + (10%) - TiO₂ and F (2.5%)-N (43%)-Er3 + (10%) - TiO₂ by degradation mechanism.In short, the degradation of nitrophenol solution by these two synthesized catalysts in the visible light achieved excellent results. The best degradation efficiency reached 87.6% and 96.87%, the effect of photocatalytic degradation of the co-doped TiO₂ is far superior to the undoped TiO₂. Our study could expand the degradation of organic pollutants by TiO₂ under visible light irradiation.