Comprehensive review on the application of inorganic and organic nanoparticles for enhancing biohydrogen production

Sudden erratic climate change due to fossil fuel combustion and a steady rise in the oil price have engaged researchers in a race to develop sustainable and economically viable fuel i.e. biofuel. Among the biofuels, biohydrogen is considered to be the most efficient and the cleanest form of energy owing to its advantages of no adverse greenhouse gas emissions and the potential to be generated from various waste biomass or feedstocks. However, the biohydrogen production through photobiological and dark fermentation techniques has often suffered from lower yield, which is considered to be a major obstacle for commercial production. Nanotechnology stands out with a promising potential for the improvement of biohydrogen production owing to its precise structural and physiochemical properties. This review provides an insight into the development of various strategies (technologies) to improve biohydrogen production using organic and inorganic nanomaterials. Initially, a systematic evaluation of the nanomaterials in biomass transformation and an elaboration on the current status of nanomaterial applications in biohydrogen production, have been addressed. The review extensively compiles and describes the use of both organic and inorganic nanoscale materials in various fermentation processes. This is followed by the advancements made in the field of nanocatalysts for improved biohydrogen production along with the possible mechanisms involved in the biotransformation of feedstocks into hydrogen production by various microbial biorefineries. Additionally, the efficiency of nanomaterials in bioreactor designing to maximize biohydrogen has been discussed. The future perspectives on the applications of nanomaterials in improving biohydrogen yield have also been discussed.