Nanomaterials play a major role in the environmental remediation based on water and air purification. Due to their diverse and tunable properties and ease of handling, they are widely explored in the areas of wastewater treatment, photocatalytic contaminant degradation, treatment of inorganic and organic air pollutants using adsorption, separation or photoreduction. Here we will explore the use of Metal Organic Frameworks, Quantum dots and Graphene based nanomaterials and their nanocomposites in such applications involving environmental remediation of air and water. Due to high adsorption surface area, high photocatalytic activity, antimicrobial properties, particle segregation qualities and other unique optoelectronic properties make nanomaterials and their nanocomposites desirable for environmental remediation. However, limitations such as dispersion and retention of the nanomaterials and extended sustainability of their antimicrobial quality act as major setbacks as this can hinder in the process of mass scale water treatment. The stability of nanomaterials in water is explored in the context as the recent contributions by Metal Organic Frameworks to the field of nanomaterials promises improved stability. Gaseous inorganic and organic pollutants, pathogens and particulate matter are the main contributors to air pollution. Photocatalysis is one of the promising techniques to purify the air contaminants into less harmful products. Advantages such as ambient conditions, strong potential of elimination of most types of air pollutants and complete degradation to harmless final products with some minute intermediate by-products render this technology as favourable from research point.