Insights into energy and environmental sustainability through photoactive graphene-based advanced materials: perspectives and promises

Abstract

Although pristine graphene is nonphotoactive, it develops the ability to absorb UV/vis light when it incorporates different light-harvesting molecules through various chemical functionalization modes or band gap engineering methods. This has become one of the most exciting topics in graphene research over the last few years, as photoactive graphene-based materials have found numerous applications that have dramatically helped in producing green energy and preserving the green environment. This review article provides a novel perspective of the topic under discussion and includes a complete overview of the field that is taken into consideration here. Furthermore, the overall development of photoactive graphene-based materials, particularly from the point of view of modification strategies that enhance their photoactive performance, is discussed along with their photocatalytic mechanisms. Moreover, efforts made by researchers to utilize natural resources are highlighted for producing green energy, particularly in converting solar light into electrical energy, producing green hydrogen from water splitting, and transforming biomass into green fuels. Wastewater treatments using advanced graphene-based photocatalysts for dye degradation and eliminating heavy metals are also exemplified with special reference to the latest photocatalytic coupling technologies for wastewater purification. According to this perspective, the different types of photoactive graphene-based nanomaterial used as photocatalysts are discussed, which simultaneously address environmental concerns about reducing pollution levels in the atmosphere and alleviate environmental degradation of various forms. With properties like an atom-thick, two-dimensional structure, high surface area, exceptional conductivity, electron mobility, anticorrosion ability, photosensitivity, and chemical stability, graphene serves as an efficient photocatalyst. Graphene derivatives are potential nanomaterials that are currently being widely investigated for diverse applications due to their exceptional mechanical, electrical, physical, and chemical properties. Technically, the review focuses on recent developments in graphene-based photocatalysts, specifically incorporating Z-scheme and S-scheme heterostructures to enhance efficiency in artificial photosynthesis for H₂ production, organic pollutant degradation, and CO₂ reduction. These processes, aligned with green chemistry principles, address energy and environmental concerns associated with global warming and green energy consumption. This approach goes well with the UN directives on SDG no. 7 that are making efforts towards clean energy and environmental sustainability.