Recent advancements in MXene-based nanocomposites as photocatalysts for hazardous pollutant degradation - A review.

The recent expeditious industrialization and urbanization showcase the increasing need for renewable and non-renewable energy and the severe environmental crisis. In this regard, numerous 2-dimensional (2D) nanomaterials have been developed as a facile approach to meet the futuristic energy essentials and to resolve the crisis. In contrast, the newly explored 2D MXenes (transition metal carbide/nitrides/carbonitride) have been employed as an intriguing material for various environmental applications. This development is accredited to their unique properties, which include a vast surface area, strong electrical conductivity, fascinating photophysical properties, high mechanical properties, stability in an aqueous medium, high hydrophilicity, biocompatibility, ease of functionalization, and excellent thermal properties. MXenes act as a potential candidate in water desalination, energy storage devices such as electrodes of Li-ion batteries and pseudo capacitors, hydrogen production, sensors, and wastewater treatment. This review article deliberates the synthesis of MXene and nanocomposites of MXene and their photo-catalytic actions against various toxic pollutants such as organic dyes and heavy metals in wastewater. This review also precises the various preparation methods of MXene-based photocatalyst and the enhanced photocatalytic activity of MXene and MXene-based nanocomposites in wastewater treatment. Also, it details the attempts made to improve the photocatalytic activity of MXene-based nanocomposites in terms of their structural compositions. In addition, the merits and demerits of the MXene-based photocatalysts are deliberated, which may pave the way for future research in this arena.

A review of graphene-based semiconductors for photocatalytic degradation of pollutants in wastewater.

Water is the lifeblood of all living things; we often overlook the fact that the water cycle and the life cycle are inextricably linked. However, it has become contaminated as a result of industrialization, which has impacted the ecosystem by emitting numerous dyes, organic solvents, petroleum products, heavy metals, chemicals, diseases, and solid wastes. The absence of treatment in reusing wastewater is the root of the issues. Hence it is essential to treat the water to preserve the ecosystem and also for human health. In recent years, graphene-based photocatalysts are attracted much in the waste water treatment process due to their outstanding physical, chemical, and mechanical properties. Since in the graphene-based photocatalyst, graphene has exceptional electron conductivity, a broad range of light absorption, a large surface area, and a high adsorption capacity. When it is integrated into metals, metal-containing nanocomposites, semiconductor nanocomposites, polymers, MXene, and other compounds, it can greatly boost the photocatalytic activity towards the photo destruction of contaminants. Hence in this review, water pollution, methods of waste water treatment, fundamental principles of photocatalysis, the photocatalytic activity of other materials in wastewater treatment, and how the photocatalytic efficiency against the removal of organic dyes can be enhanced when coalesced with graphene are detailed.