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Adsorption and photocatalytic degradation are effective ways to remove pollutants from water and achieve purification effect. In order to obtain composite aerogels with high adsorption capacity and visible light photocatalytic performance, a new type of Ag/AgBr/AgI@SiO2composite aerogels (ABIS) was prepared by in-situ synthesis and supercritical drying. It has been proved that the pore size, pore volume and specific surface area of the composite aerogels can be effectively improved by using N, N-dimethylacetamide (DMAC) as pore expanding agent. The as-prepared Ag/AgBr/AgI@SiO2composite aerogels with large pore volume, large pore size and uniform pore network structure not only showed high adsorption capacity for tetracycline, but also exhibited high separation and migration efficiency of photo-generated carriers, thereby being capable of reducing the recombination rate of photo-generated electron-hole pairs. Especially, the composite aerogel ABIS-2-N2 with loading 0.01 mol% Ag/AgBr/AgI and adding DMAC as pore-expanding agent, showed the highest adsorption/photocatalytic degradation efficiency for antibiotic tetracycline under visible light, and meanwhile exhibited high performance of photocatalytic degradation of tetracycline and recycling stability in the range of pH= 2–10. The superoxide anion (·O2-) was proved to be the main active substance to degrade tetracycline by the active substance capturing experiment. This work provides a new effective strategy for preparing composite aerogel materials with large pore volume, large pore size and adsorption/photocatalysis synergistic action, and the as-prepared composite aerogel will have important application value in the field of water purification.

Adsorption and photocatalytic degradation of pollutants are both considered to be effective ways of removing pollutants from environment. Here, a novel highly porous BiOBr/CsxWO3@SiO2composite aerogel with adsorption/self-heating photothermal catalysis synergistic effect was constructed using melamine resin as template. Multiple detection results demonstrated that the template melamine resin is conducive to expanding pore volume of the composite aerogels. Moreover, owing to the high pore volume and excellent photothermal conversion as well as the BiOBr/CsxWO3heterojunction catalysis effect, the composite aerogel with BiOBr/CsxWO3molar ratio 2:1 exhibited the most efficient removal of antibiotic tetracycline from water, with the adsorption/self-heating photothermal catalytic degradation rate of tetracycline being close to 100% after 30 min of darkroom adsorption and 60 min of light irradiation, and it also showed high removal efficiency of other pollutants. The efficient adsorption/self-heating photothermal synergistic catalysis mechanism and photocatalytic degradation pathway of tetracycline have been analyzed. This work will provide a new idea for constructing SiO2-based composite aerogel photocatalytic materials and the adsorption/self-heating photothermal catalytic synergetic effect will be a promising way for environment purification.