Development of Sunlight-Driven Reduced Graphene Oxide (rGO)/CeO2-CuO Nanofibrous Photocatalyst for Efficient Removal of Organic Dyes

Abstract

A hybrid nanofibrous membrane photocatalysts was developed through electrospinningcarbonization method. In this work, the hybrid membrane with p–n hetero-structure consisting of CeO2 and CuO metal-oxide nanoparticles was prepared by a hierarchical and facile approach through electrospun technique and stabilized by hydrothermal process. The obtained heterogeneous photocatalyst membrane was studied for its catalytic properties by performing several experiments using test solutions of anionic Congo red (CR) and cationic methylene blue (MB) dyes, respectively. The as-prepared Graphene-CeO2/CuO intercalated polyacrylonitrile nanofibrous (GCPNs) membrane is characterized by using various analytical techniques and its photocatalytic degradation properties was studied by conducting batch studies and validated using the kinetics models. Furthermore, the functional group transformation, electronic transition state, binding energy values and chemical oxidation state of the GCPNs membrane before and after degradation was investigated by spectroscopic studies. The optical properties of the GCPNs membrane was further analysed by UV-VIS diffuse reflectance spectroscopy (DRS). Also, the enhanced photo-degradation behaviour of the p–n hetero-structure due to the suppression of the recombination rate of the photogenerated electron–hole pairs was confirmed by photoluminescence studies (PL). These investigations implied that the developed photocatalyst GCPN membrane follows the pseudo first-order kinetics having higher reaction rate constant. Comprehensively, the GCPN has varying dye removal capacity of 90–98% for Congo red and 30–90% for Methylene blue in which the photocatalytic degradation capacity increases with increase in dye concentration and time. The reusability studies supported the sustainability and durability of the photocatalytic membrane for longer lifetime and practical value. Henceforth, nanotechnology-based cutting-edge technology offers novel hybrid nanomaterials having excellent properties that are pre-requisite for the development of sunlight mediated nano-photocatalytic reactors in the commercial applications.