关键词: AgBr/C₃N₅, 无机光催化涂料, 混凝土, 甲醛

Abstract:

In order to achieve efficient degradation of formaldehyde in buildings，AgBr/C₃N₅ composites were prepared by using AgNO₃，C₃N₅ and cetyltrimethylammonium bromide as precursors.The composites were characterized by X-ray patterns diffraction（XRD），Fourier transform infrared spectroscopy（FT-IR），UV-visible diffuse reflectance spectroscopy（DRS），steady-state fluorescence spectroscopy（PL），transmission electron microscopy（TEM），transient photocurrent spectroscopy（TPC） and electrochemical impedance spectroscopy（EIS）.Using metakaolin and phosphoric acid modified water glass as the main film-forming material，sodium hexametaphosphate as the dispersant，tributyl phosphate as the defoamer，sodium dodecyl sulfate as the surfactant，carboxymethyl cellulose as the emulsifier，the prepared AgBr/C₃N₅ composite material as the functional component，the AgBr/C₃N₅ inorganic photocatalytic coating was prepared by mechanical mixing method.The AgBr/C₃N₅ inorganic photocatalytic coating was loaded on the surface of concrete by spraying to study its degradation activity and stability of HCHO gas in the building.The results showed that the AgBr/C₃N₅ composite material had a wide spectral response range，efficient photoelectron-hole separation，high specific surface area and low charge mass transfer resistance to achieve efficient and stable photocatalysis.The AgBr/C₃N₅ inorganic photocatalytic coating with a mass fraction of 5% was sprayed on the surface of concrete.After 7 d of visible light irradiation，the degradation rate of HCHO reached 91.50%，showing excellent HCHO degradation activity.The degradation rate of HCHO was still higher than 90% after 10 times of recycling，showing good durability.

Key words: AgBr/C₃N₅, inorganic photocatalytic coating, concrete, formaldehyde