Photocatalytic deposition of cobalt atoms on two-dimensional nanocomposites as efficient visible-light-driven photocatalysts: Experimental study and intelligent modeling

Abstract

In this work, two-dimensional (2D) based photocatalysts containing TiO2 nanosheets (TNs) and reduced graphene oxide (rGO(x)) were fabricated using a hydrothermal method. Various quantities of cobalt atoms were deposited on TNs/rGO(x) by the photocatalytic deposition method (Co(y)/TNs/rGO(x)). The results of XRD and Raman spectroscopy analyses showed that the TNs have a pure anatase phase and graphene oxide was adequately reduced during the hydrothermal condition. Based on the DRS analysis, it was observed that the band gap energy of the synthesized samples was decreased compared to the one for pure TNs. The highest photocatalytic activity was obtained by the Co(76)/TNs/rGO(5) sample with 71.5% degradation of tetracycline (TC) (30 mg/L) under the visible light after 180 min. The active species scavenging tests also showed that OH• and h+ were the main species involved in the degradation of TC. The Co(76)/TNs /rGO(5) sample recovery and reusage experiments did not show a significant reduction in the photocatalytic performance after five consecutive cycles. Finally, the Artificial Neural Network (ANN) and Adaptive Neuro-Fuzzy Inference System (ANFIS) models were developed to predict the photocatalytic degradation performance of the fabricated photocatalysts. Both the experimental and modeling results confirmed that the 2D-based photocatalysts developed in this study can be considered as promising candidates for wastewater treatment applications.