TiO2/SiO2　composite　nanotube　photocatalysts　supported　on　Al　substrates　were　prepared　by　the　anodic　aluminum　oxide　(AAO)　liquid-phase　deposition　method　for　degradation　of　100　mg/L　methyl　blue　(MB).　AAO　templates　were　prepared　in　H3PO4　acidic　electrolytes　through　the　two-step　anodic　oxidation　method.　The　photocatalysts　were　characterized　by　field-emission　scanning　electron　microscopy,　thermal　analysis　(TG-DTA),　and　Fourier-transform　infrared,　x-ray　photoelectron,　and　UV-Vis　diffuse　spectroscopies.　The　results　showed　that　the　presence　of　SiO2　in　TiO2　inhibited　the　crystal　phase　transformation　temperature　effectively,　with　a　greater　wall　thickness　of　80-100　nm.　It　was　found　that　Ti-O-Si　bonds　were　formed　on　the　surface　and　the　surface　hydroxyl　concentration　was　increased,　resulting　in　enhanced　photocatalytic　activity,　being　about　20%　higher　than　for　pure　TiO2　films.　The　calculated　band　structure　for　TiO2/SiO2　was　investigated　using　first-principle　calculations.　The　TiO2/SiO2　composite　exhibited　a　wider　conduction　band　which　would　effectively　prohibit　recombination　of　photo-generated　electrons　and　holes.