Composite aerogel photocatalyst for recovering titanium dioxide/silicon dioxide

Abstract

The invention relates to a recoverable TiO2-SiO2 composite aero-gel photo-catalyst as well as the preparation method thereof. The invention is characterized in that the sol-gel method is firstly utilized for respectively preparing TiO2 sol and SiO2 sol, then the two are mixed according to a certain proportion to obtain a mixed sol, and then TiO2-SiO2 composite alcogel is obtained through polycondensation reaction; the TiO2-SiO2 composite alcogel is used for preparing TiO2-SiO2 composite aero-gel after drying, and the composite aerogel is used for obtaining composite aero-gel aggregates after baking for 6 to 8 hours. The pore size of the obtained composite aero-gel aggregates is distributed between 2.5 nm to 10 nm, and the particle diameter is distributed between 10 nm to 15 nm, while the particle diameter of the aggregates is distributed between 0.1 mm and 0.3 mm. Compared with the prior art, the TiO2-SiO2 composite aero-gel photo-catalyst has the advantages that the prepared TiO2-SiO2 composite aero-gel has large specific surface area, high porosity, uniform pore distribution, etc., wherein, TiO2 is in the anatase crystal form. Compared with the TiO2 nanometer powder absorbent, the photo catalytic activity of the TiO2-SiO2 composite aero-gel is higher, the photo catalytic efficiency is better, and the regeneration and the reuse of the composite aero-gel are convenient as the particles of the aero-gel aggregates are larger, thereby the recoverable TiO2-SiO2 composite aero-gel photo-catalyst is widely applicable to the treatment of a great amount of wastewater.

Description

technical field [0001] The invention belongs to the technical field of photocatalysts and relates to a recyclable TiO 2 -SiO 2 Composite airgel photocatalyst and preparation method thereof. Background technique [0002] In recent years, the problem of water pollution in our country has become increasingly serious, and the traditional sewage treatment methods have become increasingly unable to meet the needs of practical problems. The research on highly active heterogeneous semiconductor photocatalytic materials has brought a ray of hope to the problem of sewage treatment. Since this photocatalytic material can decompose or absorb pollutants in water only under sunlight conditions, it has been widely valued by the majority of scientific researchers. , There are more and more research papers and patents in this area. [0003] Semiconductor catalysts such as TiO 2 , ZnO, CdS, WO 3 , SnO 2 , Fe 2 o 3 It has shown broad prospects in wastewater treatment, air purification,...

AI Technical Summary

Problems solved by technology

Zhang Jinlong and others disclosed a preparation method of titanium dioxide mesoporous material in the patent CN1594102A. The material is prepared by using titanate hydrolysis method to obtain nanoparticles, and then using surfactant as a linking agent to connect the nanoparticles. Among them, nano-titanium dioxide The particles are in the anatase phase, but according to our experiments, nano-scale particles are generally not obtained by titanate hydrolysis, and the patent is only for TiO 2 Unary substance

Deng et al reported TiO on Nanostructure Materials11(1999) 1313 2 Airgel and TiO in different proportions 2 -SiO 2 The photocatalytic degradation performance of airgel to phenol, but the literature does not provide the preparation process

Anderson et al reported TiO on J Phys Chem B 101(1997) 2611 2 with SiO 2 There is a synergistic point of view between, but only for SiO 2 Evenly dispersed in TiO in the form of molecules or small particles 2 Around, no chemical bonds are formed, so the chemical stability is not good

Gu Mingyuan etc. disclose a kind of nitrided TiO on the patent CN 1273214C 2 -SiO 2 Composite powder catalyst, but the result is photocatalytic powder instead of composite airgel, which is not conducive to recycling and reuse

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