Generally, the present thesis consists of two sections in which graphitic carbon nitride (g-C 3 N 4 ) were studied by DFT method and the role of deposited transition metals on the optical properties of g-C 3 N 4 were investigated. In the next section new modification methods for improving the carbon fiber felt features introduced and proper nanocatalysts for catalytic oxidation of organic compound were prepared. In the first project, the adsorption of Pdn cluster with different size (n=2–8) on graphitized carbon nitride (g-C 3 N 4 ) quantum dot has been studied using the density functional theory (DFT). Various complexes showed tendency for landing at different sites and have various charge transfer direction depended on the cluster size. In the second project Pd 2 /g-C 3 N 4 were used for investigation of the acetylene hydrogenation. This catalyst finally reduced activation energy of acetylene hydrogenation rather to the ethylene reduction and as a results has more selective for preparation of ethylene. In the third study, a mesoporous photo-catalyst based on Au-Pd nanoparticles incorporated into g-C 3 N 4 was prepared by a co-assembly method. The results demonstrated that the Au-Pd-containing catalyst exhibited superior performance compared to its counterparts containing monometallic nanoparticles. In the next project fabrication of a novel catalyst based on carbon fiber felt (CFF), which was achieved through three steps: co-assembly with immobilization, flooding and condensation. Efficient immobilization of Au-Pd bi-metallic and very regular spring-like TiO 2 layer around the Au-Pd/CFF structure are two main distinct features of the newly-prepared catalyst. And in the final project cobalt nanoparticles deposited on the nitrogen-doped CFF were coated by coil shape mesoporous TiO 2 -SiO 2 and the final catalyst were used in the aerobic oxidation of ethylbenzene in mild conditions.
