Investigation of structural characteristics and optical properties of gC3N4-Cu2O, gC3N4-TNTs/TiO2 nanocomposit materials prepared by the hydrothermal method
Abstract
The gC3N4-Cu2O, gC3N4-TNTs/TiO2 nanocomposites were fabricated by the hydrothermal method. The doping ratio of gC3N4 nano to Cu2O was 10 mol. % and to TNTs/TiO2 was 15 mol. % (compare the molarity of Cu2+ and Ti4+, respectively). The structural characteristics of the materials were determined by the methods: XRD, SEM/EDX. The optical properties of the materials were determined by the absorption spectroscopy method. Results showed that, the gC3N4-Cu2O, gC3N4-TNTs/TiO2 samples were nano-meter structure. The gC3N4 - Cu2O sample had octahedral crystals with grain size ~ 300 - 400 nm. The gC3N4 - TNTs/TiO2 sample had nanorods crystals with length size ~ 5 - 10 µm and width size ~ 80 -100 nm. On the surface of the crystal particles of gC3N4 - Cu2O, gC3N4 - TNTs/TiO2 nanocomposites were interwoved with gC3N4 translucent cotton-like crystals. The absorption spectra of nanocomposites all had extended absorption edge and were intermediate in the range of extended absorption edge of single-phase materials, respectively. The band gap energy (Eg) of gC3N4 - Cu2O, gC3N4 - TNTs/TiO2 nanocomposites were 2.01 eV, 3.39 eV, respectively. This Eg value was determined to be an intermediate value between the Eg values of the single-phase Cu2O, TNTs, TiO2 nanomaterials (Eg » 2.17 eV, 3.61 eV, 3.2 eV, respectively) and the doped gC3N4 nanomaterials (Eg » 2.73 eV).
