Struktur dan Aktivitas Fotokatalitik Komposit Graphitic Carbon Niitride/TIO2 Nanotube (G-c3n4/Tnt) dengan Variasi Persen Massa G-c3n4 terhadap Naphthol Blue Black

Abstract

TiO2 nanotubes are n-type semiconductors that are widely applied as photocatalysts. However, this material is only able to absorb ultraviolet (UV) light. The addition of graphitic carbon nitride (g-C3N4) can expand the absorption region to the visible light region because it has a smaller band gap. This study aims to evaluate the effect of variations in the mass percentage of g-C3N4 (0-100%) on the characteristics, physicochemical properties, and photocatalytic properties of gC3N4/TNT composites. The results of X-ray Diffraction (XRD) characterization show the anatase phase of TiO2 and g-C3N4. Fourier Transform Infrared Spectroscopy (FTIR) characterization shows the absorption bands of OH, O-Ti-O, C-N, and C=N groups. The Raman spectrum displays the characteristics of the anatase phase of TiO2 and the heptazine structure of g-C3N4. Scanning Electron Microscope (SEM) characterization shows the structure of TNT and g-C3N4 nanotubes in the form of sheets. Energy Dispersive X-ray (EDX) analysis detected Ti, C, and N elements in the composite, with the C and N contents increasing with increasing mass percentage of g-C3N4. Brunauer-Emmett-Teller (BET) analysis showed that the specific surface area decreased with increasing mass percentage of g-C3N4. UV-Vis Diffuse Reflectance Spectroscopy (UV-Vis DRS) analysis showed that the band gap value of g-C3N4 decreased gradually from 3.2 eV to 2.70 eV. The photocatalytic activity test against Naphthol Blue Black (NBB) was evaluated through adsorption in dark conditions and under visible light illumination for up to 210 minutes. The optimum adsorption results were at 20 and 30 minutes. The 20% g-C3N4/TNT composite showed the highest photocatalytic activity with degradation efficiencies based on C0 and C1 calculations of 83.88% and 73.16%, respectively.