Optimization of photocatalytic performance of a gC3N4–TiO2 nanocomposite for phenol degradation in visible light

Abstract

In the current study, response surface method (RSM) was used to optimize the photocatalytic performance of a graphitic carbon nitride (gC3N4)–TiO2 nanocomposite, which was fabricated in a single step anodization technique. The RSM statistically established the optimal conditions for the assessment and design of the experiments. We examined the effect of different operating parameters of gC3N4–TiO2 nanocomposites (such as melamine dose, annealing temperature, and annealing time) on phenol degradation in visible-light. From RSM results, the optimum synthesis condition was observed when gC3N4–TiO2 nanocomposite was fabricated at a melamine dose of 2.08 g, annealing temperature 575.4 °C, and annealing time 2.93 h. This optimum sample showed 3.9 times higher phenol degradation efficiency than pristine TiO2 nanotubes. The gC3N4–TiO2 nanocomposite was characterized with field emission scanning electron microscopy, X-ray photoelectron spectroscopy, X-ray diffraction, energy dispersive X-ray spectroscopy, and UV–Vis diffuse reflectance spectroscopy. From recycling results, it was observed that the gC3N4–TiO2 nanocomposite was stable for many cycles. We observed that the RSM model predicted data are in a good agreement with phenol degradation experimental data with R2 value of 0.988. It was established that the RSM is a viable technique for optimal synthesis of a nanocomposite that can effectively degrade the pollutant.