Enhanced photocatalytic performance of TiO2–carbon nanocomposite

Abstract

In this study, modification of titanium dioxide with carbon material of coconut husk fiber is reported. Synthesis of carbon nanoparticles (CNPs) and their composite with TiO2 have been proposed for the first time by carbonization and acid digestion of coconut husk fibers through the sol–gel method comparatively at low temperature. XRD patterns show the anatase structure of the TiO2–carbon nanocomposite. HR-TEM indicates the formation of TiO2–carbon nanocomposite with 10–15 nm size. The FT-IR spectra show the strong absorption between 500 and 800 cm−1 of Ti–O–Ti in both TiO2 and composite. From DRS spectra, it is seen that bandgap energy (Eg) of TiO2 nanoparticles (3.14 eV) decreases noticeably in nanocomposite (3.05 eV). From BET, it is clear that specific surface area of TiO2 and composite are 66.18 and 121.74 m2 g−1, respectively. FE-SEM images show that composite material is made of microspheres with different sizes and a smooth surface. The EDS result depicts no other peaks except Ti, C, and O indicating the high purity of the composite obtained through this method. Evaluation of photocatalytic activity for the composite was performed via degradation of the methyl orange (MO) under UV light irradiation. The photocatalytic degradation is seen to be a pseudo-first-order, and the value of the rate constant for TiO2–carbon nanocomposite is higher than TiO2. TiO2–carbon nanocomposite shows a 50% increment in MO degradation than pristine TiO2.