Recent progress in understanding the role of graphene oxide, TiO2 and graphene oxide-TiO2 nanocomposites as multidisciplinary photocatalysts in energy and environmental applications

Abstract

The rapid advancement of global industry has led to critical energy shortages and environmental pollution, prompting researchers to develop simple and efficient solutions. Emerging 2D nanomaterials as sole photocatalyst and their heterostructures with traditional photocatalysts not only have boosted their photocatalytic efficiency but also have provided multifunctionality to their potential uses. The present review details on recent developments carried out on graphene oxide (GO) nanomaterials and their heterostructures with metal oxide photocatalysts (particularly GO/TiO2 which is the most studied nanocomposite photocatalyst system) for their potential multidisciplinary photocatalysis applications in the field of energy and environment. It particularly focuses on understding the role of GO as an emerging sole and multidisciplinary photocatalyst as well as its role in boosting photocatalysis efficiency of tradiaitonal metal oxide photocatalysts. This review explores the fundamental photocatalytic mechanisms of GO and synthesis of GO/TiO2 nanocomposites with emphasis on their multifunctional photocatalytic applications on the topics of current interests including photocataltytic H2 production, CO2 photoreduciton, photodegradation of nano-micro/plastics and other pollutants of emerging concern (i.e., pesticides, pharmaceutical, personal care products, pathogens/viruses etc.) etc. which have rarely been reviewed in past years. In addition, structural and morphological (0-3D) investigations, surface chemistry, stability/recyclability of nanostructures and potential use of direct/natural sunlight for the sustainable development along with computational aspect, have been highlighted along with their toxicity towards the health and environment. Finally, various challenges, in view of emerging GO as a sole promising photocatalyst and its nanocomposites, have been discussed along with their potentials to provide sustainable solutions to energy shortages, clean energy and environmental pollution.