Microalgal Extracts-induced Biogenic Reduction Of Graphene Oxide (GO) And Its Application

Graphene oxide(GO)and its reduced form(rGO)has attracted a significant attention in the modern scientific era.A proper reduction of graphene oxide is of utmost importance,in order to maintain its original properties while enhancing its efficacy.Traditionally,various hazardous chemicals are under practice for GO reduction,consequently,these chemicals exert a potential danger to inhabitants of different environments including human.Hence,alternative eco-friendly strategies are required to reduce GO utilizing biomolecules from green renewable sources e.g.plants,algae,and cyanobacteria.In the current study,a new strategy was adopted and different microalgal strains were employed.Their reducing potentials were explored and then utilized for the green reduction of GO into rGO.Bioactive molecules in the aqueous extracts of different microalgae such as(Scenedesmus vacuolatus(strain 211-11n),Chloroidium saccharophilum(strain 211-9a)and Lyptolyngbya strain(JSC-1)were exploited as sources of green chemicals to reduce graphene oxide.Spectral changes in the surface plasmon resonance of GO(227 to 287 um)and variation in D and G bands in Raman spectrum confirmed the successful reduction of graphene oxide into reduced graphene oxide.The morphology and crystalline structure of the reduced graphene oxide were confirmed by transmission electron microscopy(TEM)and X-ray analysis.A successive decrease in the surface potential from-43(GO)to-17 mV further supports the reduction of GO into rGO(zeta potential analysis).The synthesized biogenic rGO was then used as an adsorbent for the removal of heavy metals such as lead(Pb)and copper(Cu).The adsorption at different intervals of time,revealed a high percent removal of Pb(95±2%)and Cu(96±2%),indicating the efficacy of biogenic rGO as an excellent material for the removal of heavy metals from polluted water,and could be an efficient adsorbent for other environmental pollutants.Furthermore,the use of microalgae as a source of reducing biomolecules will avoid the utilization of hazardous chemicals for the reduction of GO into its reduced form,hence a potential threat to the environment will be minimized.