Cu-Doped Zno/Tio2 Photocatalyst: Synthesis, Characterization and Effectiveness on Band Gap Energy Level

Copper doped zinc oxide/titanium dioxide nanocrystals (cu-zno/tio2) were synthesised by entrapping copper ions in a crystalline matrix of zno/tio2 through the sol-gel method# copper with different concentrations between 1% and 5 % were loaded into a photocatalyst matrix with the tio2/zno ratio of 70% to 30%# the matrix was calcinated at two different temperatures of 500°c and 700°c# thermal property and absorption spectra of cu doped zno/tio2 were characterized by thermogravimetric analysis (tga) and a uv–vis spectrophotometer# besides, the band gap energy level of the synthesized catalyst was estimated through kubelka-munk’s model and plank equation# the results revealed that cu-zno/tio2 had a more thermally stable lattice compared to tio2/zno and therefore the phase transformation from anatase to rutile was retarded under higher calcination temperature in the cu-zno/tio2 lattice# apart from calcination temperature, dopant content was found to affect optical band gap energy level# accordingly, the narrowest band gap level was observed in the sample with the copper content of 3wt%, calcinated at 500°c# among the samples, the doped photocatalysts that were calcinated at 500°c, showed low band gap energies which was were to the presence of cuo and cu2o on the surface of the photocatalyst and/or from the residual copper due to incomplete pyrolysis# cupric oxide, cuo has a band gap energy level of 1#4ev while cuprous oxide, cu2o has a band gap energy level of 2#2ev#