Self‐assembled Carbon Nanophotocatalysts: An Eco‐friendly Strategy for Environment and Energy Conservation

Nanoparticles provide greater specific surface area, plasmonic properties (localized surface plasmon resonance), and photocatalytic activity (nanophotocatalysts) for removal, depending on their physicochemical characteristics such as size, pH, temperature, charge, time, crystallinity, etc. Carbon nanophotocatalysts are an efficient scaffold for the environment and green energy generation, and can also be easily synthesized from C-rich biomass such as biowaste reserves and algae/cyanobacteria. Also, they are more efficient (bottom-up/top-down), commercially scalable, cost-effective, benefited by the circular economy, and sustainable nanophotocatalysts with stability. Self-assembled nanophotocatalysts are synthesized with controlled architecture, release fewer harmful substances, and are useful for pollutant removal from the environment, including green bioenergy generation. Among the green/biogenic synthesis of carbon nanophotocatalysts, algae/cyanobacteria (phyco/cyano nanotechnology) are more promising as they present biological factories with suitable growth rate (photosynthetic efficiency), carbon sequestration potential, and can be cultivated under flue gas in diverse water sources (freshwater/seawater/hypersaline), and wastewater outdoor (energy-efficient) with a few additional nutrients and cultivation skills. Therefore, it is worthwhile to study the construction of self-assembly and photocatalysis of carbon nanoparticles for environmental remediation and green energy generation with emphasis on biogenic synthesis.