Methods for preparing and applying titanium dioxide-carbon composite photocatalyst

Abstract

The invention relates to methods for preparing and applying a titanium dioxide-carbon composite photocatalyst. The technical scheme is that the method for preparing the titanium dioxide-carbon composite photocatalyst comprises the following steps of: preparing an ordered macroporous-mesoporous carbon material and TiO2 sol respectively, soaking the aged TiO2 sol on the prepared macroporous-mesoporous carbon material by an impregnation method, drying, raising the temperature and calcicining to obtain a TiO2 / C composite photocatalyst material. The method for applying the titanium dioxide-carbon composite photocatalyst is that photocatalytic reaction conditions are that: the adding amount of the titanium dioxide-carbon composite photocatalyst is 1 to 6g / L; a light source is an ultraviolet or visible light source and directly irradiates a solution, the depth of the solution is 0.4 to 0.6cm, and the exposure dose per unit area on the surface of the solution is 12.5 to 12.8mW / cm<2>; and the temperature of a solution system is kept at 20 to 40 DEG C, and air is continuously introduced to maintain the concentration of dissolved oxygen. Macroporous-mesoporous carbon material supported titanium dioxide is used as a photocatalyst, so that TiO2 has high dispersity and photocatalytic activity, and is easier to recycle.

Description

technical field [0001] The invention belongs to a photocatalytic material and its preparation method and application, in particular to a preparation method and application of a titanium dioxide catalyst with high photocatalytic activity for removing organic pollutants in water. Background technique [0002] With the rapid development of industrial production, a large amount of waste is continuously discharged into nature, which makes the living environment of human beings worse and worse, and the problem of water environment pollution is particularly serious. Wastewater contains a large number of organic pollutants, many of which are difficult to biodegrade, such as phenols, polychlorinated biphenyls and polycyclic aromatic hydrocarbons. Their biological toxicity is relatively high, which seriously threatens human health and life. Dye wastewater occupies a considerable proportion of various wastewater to be treated. Dye wastewater has deep chroma, high concentration, and hig...

AI Technical Summary

Problems solved by technology

[0004] But as a good photocatalyst, TiO 2 There are some defects: (1) The band gap is wide, it can only absorb ultraviolet light, it has no response in the visible light range, and the utilization rate of sunlight is low (about 3~5%); (2) The recombination rate of photogenerated carriers is high, Photocatalytic efficiency is low

(3) Due to TiO 2 Its own hydrophilicity is very strong, and the ultrafine TiO 2 The powder is very easy to agglomerate. Therefore, it is difficult to separate from the water phase after directly using a nano-powder photocatalyst similar to titanium dioxide to treat wastewater, resulting in new and more difficult-to-handle secondary pollution.

[0005] Although the TiO 2 Carrying on the above-mentioned carriers can play a certain role and play a role in facilitating recovery, but when using microporous or mesoporous materials as carriers, it will usually cause TiO 2 The inhomogeneous distribution on the surface of the pores and the tendency to agglomerate will greatly reduce the adsorption performance of the porous material itself.

On the other hand, usually TiO 2 Particles are adhered to the surface of the pores by different linkers, TiO 2 There is no barrier around itself, and the adhesive connection is not very strong. When it is in full contact with the fluid, it is easy to fall off under the impact of the fluid, resulting in the loss of the catalyst and a significant decline in the recovery performance.