Sustainable Growth and Lipid Production from Chlorella pyrenoidosa Using N-Doped Carbon Nanosheets: Unravelling the Role of Graphitic Nitrogen

The advent of novel carbonaceous nanomaterials (CMs) associated with microalgae paved an alternate way for the bioeconomic production of biofuels as well as high value added compounds. Herein, we for the first time, present a holistic approach for sustainable biomass and lipid production from Chlorella pyrenoidosa, wherein CMs, namely N-doped carbon nanosheets (CNS) and N-doped graphene nanosheets (NGS) were used as one of the algal growth supporting factors. Doping carbon nanomaterials with nitrogen can effectively tune its electronic structure and other intrinsic properties for efficient photocatalysis. The utilization of CNS and NGS in this process lead to rapid, environment friendly, and facile assimilation of biomass and lipids for the development of nutraceuticals, pharmaceuticals, and other bioenergy associated applications. Employing a suite of characterization methods, the intrinsic structural and morphological properties of CMs were revealed. Compared with control, the lipid content obtained in the presence of undoped carbonized carbon materials (CCM), CNS, and NGS were found to be around 1.5-,2-, and 6-fold higher, respectively, at similar growth conditions. We, therefore, envisage that graphitic nitrogen rich NGS plays a pivotal role in enhancing the lipid production from algae. This finding, therefore, exhibits a promising potential to bring about a paradigm shift in the field of bioenergy frameworks.