Organic and inorganic binder-coating properties for immobilization of photocatalytic ZnO nanopowders

摘要

Five kinds of organic binders, three kinds of inorganic binders, and four kinds of organic–inorganic double-layer binders were prepared to immobilize photocatalytic nanopowders. Three kinds of photocatalytic nanopowders (two kinds of TiO₂ nanopowders and a kind of ZnO nanopowder) were also prepared to investigate the coating properties of the binders on glass substrates. The coating properties were analyzed by several measurement methods such as contact angle, SEM, EDX, and scratch test. In general, organic binders have good coating properties but they could be decomposed by photocatalytic reaction. Inorganic binders, however, have poor coating properties but they are not decomposed by photocatalytic reaction. Contrary to the general aspect, the zinc phosphate inorganic binder synthesized in this work showed the best overall coating properties with the ZnO photocatalytic nanopowder. These abnormally good coating properties might be attributed to the strong bond formation between ZnO photocatalytic nanopowder and the zinc phosphate binder.