Preparation of nano-TiO₂ by waste clay bricks and photocatalytic effect on concrete

In this paper, a composite photocatalyst is prepared by using waste clay bricks to adsorb nano-titanium dioxide (TiO₂), and a decorative concrete surface layer is made by using it. Then, it is found that reclaimed clay sand (RCA) prepared by building waste clay bricks has poor workability, with a relative strength between 40% and 80%, but can meet the strength requirements of ordinary building mortar. Compared with RCA, natural sand (NS) has lower water absorption, coarser particles and higher hardness. The relative strength of the mortar prepared using NS is between 50% and 80%, which also meets the basic strength requirements of the mortar. In terms of photocatalytic effect, the decorative concrete surface layer prepared using the composite photocatalyst has a good photocatalytic effect and can effectively degrade nitrogen oxide (NO_x) in automobile exhaust. The decorative concrete surface layer made of NS has lower nitrogen oxide degradation efficiency than RCA. The photocatalytic concrete surface layer prepared using RCA loaded with nano-titanium dioxide has good photocatalytic durability.