Harnessing sunlight for biomass deconstruction and solar biofuel production

The development of next-generation visible-light-active photocatalysts, like composite semiconductors, metal-organic frameworks (MOFs) and carbon-based materials, which harness energy from wide solar spectrum, has been utilized in the valorization lignocellulosic biomass. Capturing these developments, this review focuses on the potential of such a photocatalyst to perform deconstruction of complex biomass. A detailed discussion is made on the recalcitrance nature of lignocellulosic biomass and the characteristics of the photocatalysts adapted for targeting the deconstruction. Specifically, the roles of MOF, Carbon-based materials, and the hybrid photocatalysts systems, namely, photothermal and photoelectrocatalytic, in deconstructing and saccherifying the biomass is elaborated. Mechanism of photocatalysis prevailing in each of these materials, and their comparative performance analysis in driving the fermentable sugars, reduction to organic and other value-added products are brought out. Significant findings indicate that improvements in carbon-based catalysts and MOFs greatly increase the absorption of visible light, offering prospective conversion methods that are both economically viable and environmentally benign. It is further demonstrated that the photocatalysed biomass is adaptable directly into the down-stream fermentation process, producing ethanol. In perspective, recent development in magnetically retrievable catalysts and 3D print immobilized catalysts has given further impetus to the development of scalable technological processes.