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 oC, 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.