Recently, nanotechnology has begun to be applied in biofuel generation. This is due to their distinctive physical characteristics, such as tiny size (nanoscale size), huge surface area-to-volume ratio, and catalytic activity, which all contribute to an increase in the yield of numerous kinds of biofuels, such as biohydrogen, biodiesel, biogas, or bioethanol, from various types of biomass, such as agricultural residue, algae, or waste activated sludge. Biofuels are dependent on progress in the production of biomass and can be used not only for the production of sustainable energy but also as a way of capturing and storing CO2. Some biofuel production is catalyzed by nanoparticles that are considered carbon negative as their production pulls out carbon from environment. A major benefit of biofuels is the amount of energy required for their production, which is significantly reduced compared to fossil fuels.

To address serious issues in the modern biofuel industry, the standardized use of nanotechnology and the integration of various pre-treatment processes are vital. A primary goal of this integration is the reduction of waste or the increased utilization of waste. Nanotechnology-integrated biorefineries are processing facilities that convert biomass into value-added products such as biofuels, biochemicals, bioenergy or biopower, and other nano-biomaterials, and enhance the quality of the end product through optimization. Increased yields of biofuel from biomass can be achieved through the establishment of various nano-catalyst strategies and by integrating the latest nanotechnology-based bioprocessing techniques into biorefineries. In addition, research into the utilization of different kinds of biomass, such as agricultural residues or microalgae, has great potential as am alternative source of biofuels and value-added products. These can also be improved through the integration of nanotechnology.

The aim of this Special Issue is to describe recent progress in nanotechnology-based biomass conversion and to summarize current trends related to biofuel production, including the latest experimental techniques and methods used to investigate the fundamental questions in this area. We welcome both original research and review articles.

Potential topics include but are not limited to the following:

• Nanotechnology-based methods for the conversion of biomass to biofuel
• Design of innovative nano-catalyst strategies for the conversion of biomass into various biofuels, including biomethane, biodiesel, bioethanol, biohydrogen, biobutanol, or microbial fuel cells
• Development of nanomaterials for sustainable biomass pretreatment to improve the possibility of commercialization or production on industrial scales
• Deep exploration into nanotechnology-integrated biorefinery approaches to maximize biofuel yields
• Biostimulation of nanoparticles for the enhancement of biofuel production
• Commercial exploitation of nanostructured constituents in biofuel improvement, as well as biofuel harvesting and associated nanodevices for biofuel storage
• Role of nanoparticles in the economic and environmental sustainability of biofuels from biomass