The application of graphene and its derivatives in energy conversion, storage, environmental and bio-sensing devices

Graphene (GR) and its derivatives are promising materials on the horizon of nanotechnology and material science and have attracted a tremendous amount of research interest in recent years. The unique atom-thick 2D structure with sp2 hybridization and large specific surface area, high thermal conductivity, superior electron mobility and chemical stability has made GR and its derivatives extremely attractive components for composite materials for solar energy conversion, energy storage, environment purification and biosensor applications. This review gives a brief introduction of GR's unique structure, band structure engineering, physical and chemical properties, recent energy-related progress of GR-based materials in the field of energy conversion (e.g., photocatalytic, photoelectrochemical water splitting, CO2 reduction, dye sensitized and organic solar cells, and photosensitizer in photovoltaic devices) and energy storage (batteries, fuel cell and supercapacitors) applications. The vast coverage of advancements in environmental applications of GR-based materials for photocatalytic degradation of organic pollutants, gas sensing and removal of heavy metal ions is presented. Additionally, the presences of graphene composites in the bio-sensing field have been discussed in this review. We concluded the review with remarks on the challenges, prospective and further development of GR-based materials in the exciting field of energy, environment, and bioscience.