Rhodium-doped titanium dioxide composite material, preparation method and photocatalytic application thereof

Abstract

The invention discloses a rhodium-doped titanium dioxide composite material, a preparation method and photocatalytic application thereof. The present invention prepares a Rh(IV) solution by oxidizing Rh(III) with sodium bismuthate under acidic conditions, and uses a hydrothermal synthesis method to dope Rh(IV) into TiO by in-situ replacement. 2 The material is used as a precursor, and then the bismuth element in the composite material is washed out by strong acid to prepare rhodium-doped TiO 2 composite material. The color of the composite material is related to the doping ratio of Rh(IV). With the increase of the doping ratio of Rh(IV), the RhTiO 2 The color also gradually changes from white to yellow, yellow-green to gray. Rh(IV)‑TiO 2 The optical band gap of the material is about 2.72-3.0eV, showing good catalytic performance under visible light. Rh(IV)‑TiO 2 Under the excitation of visible light with a wavelength greater than 400nm, the material can decompose acetic acid significantly better than undoped TiO 2 . Under the excitation of visible light with a wavelength greater than 450nm, Rh(IV)‑TiO 2 Material decomposes isopropanol significantly better than undoped TiO 2 .

Description

technical field [0001] This patent relates to the technical field of photocatalysis and environmental treatment, in particular to a visible light catalytic material containing tetravalent rhodium ions and a preparation method thereof. Background technique [0002] Photocatalytic technology has broad application prospects in the fields of environmental pollutant treatment, hydrogen production by photolysis of water, and solar cells. Studies have found that hundreds of major organic or inorganic substances can be decomposed by photocatalytic oxidation. Using TiO 2 Photocatalytic degradation of organic pollutants is currently a research area of ​​great concern in the world, but TiO 2 It can only absorb ultraviolet light with a wavelength less than 387nm, and has no photocatalytic activity under visible light irradiation. Because only less than 4% of the light energy in sunlight is ultraviolet light, and artificial ultraviolet light sources have defects such as high power con...

AI Technical Summary

Problems solved by technology

Using TiO 2 Photocatalytic degradation of organic pollutants is currently a research area of ​​great concern in the world, but TiO 2 It can only absorb ultraviolet light with a wavelength less than 387nm, and has no photocatalytic activity under visible light irradiation

Because only less than 4% of the light energy in sunlight is ultraviolet light, and artificial ultraviolet light sources have defects such as high power consumption, expensive equipment, and poor stability, a new photocatalyst has been developed to enable it to absorb visible light in sunlight. Oxygen in the air is used as an oxidant, and the effective degradation of organic pollutants has become a key scientific problem in the field of photocatalysis

However, Rh(IV)-doped or co-doped TiO 2 Photocatalytic materials are rarely reported, mainly because the outermost layer 4d of Rh(IV) 5 There is a single electron in the orbital, which makes it very active, making it difficult to obtain a stable Rh(IV) solution

Moreover, the currently reported photocatalytic materials involving Rh(IV) doping modification are all prepared by high temperature (>900°C) process, and the oxidation operation is complicated.

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