Abstract

The depletion of the fossil fuel reserves on the Earth as well as the rapid increase in green-house gas emissions and environmental pollutions propel the development of renewable energy technologies. Lignin next to cellulose and hemicellulose is one of the three subcomponents of lignocellulosic biomass in terrestrial ecosystems and represents nearly 30% of the organic carbon sequestered in the biosphere but most underutilized, which has a high potential for application value of decomposition into valuable chemicals and fuels as fossil fuel alternative due to the richness in aromatic carbon. However, the complex and stable chemical bonds of lignin make the lignin depolymerization a tough challenge with regards to its valorization. In this review, we highlight recent advances in photocatalytic selective decomposition of lignin-based compounds into other value-added chemicals and lignin wastewater treatment, and particularly demonstrate the promising scope of photocatalytic transformation of lignin under mild conditions.