The energy crisis is at the top of global priorities. It left us with an option to progress with highly efficient materials for energy conversion, production, and storage systems. Carbon nano-allotropes have more accessible, and modifiable surface with excellent surface area, conductivity, catalytic activity, and other features. Biochar synthesized from renewable organic materials such as plants and animal waste, have beneficial physicochemical features (surface functionalities, porosity, adsorption capacity, etc.) and agronomic properties. They are influenced by several factors like the type of thermal treatment and feedstocks. Modification of biochar is an excellent option to obtain synergistic effects and sustainable materials. The current comprehensive review article will focus on biochar, selected nanocarbons (fullerene, carbon dots, nanotubes, nanodiamonds, graphene, and graphdiyne), and their hybrids for hydrogen evolution. Particular emphasis will be on biochar as these materials could be easily generated from different wastes. Biochar can have graphitized or non-graphitized carbon atoms. They can have carbon fragments resembling fullerene. This can be a potential low cost biocarbon alternative to graphene and fullerene and we are well aware of the importance of graphene and fullerene. Future projections in this paper may lead to an added foundation for “trash to treasure”/ “waste to wealth” and “waste to fuel” research and also contributes towards real-world applications in the clean fuel and sustainable energy sector.