Confined synthesis of BiVO4 nanodot and ZnO cluster co-decorated 3DOM TiO2 for formic acid production from the xylan-based hemicellulose photorefinery†
The biomass photorefinery provides a promising strategy for value-added chemical production from natural feedstocks. Herein, we designed and fabricated a three-dimensionally ordered macroporous (3DOM) ternary composite for the photoreforming of hemicellulose and the corresponding monosaccharides. This hierarchically porous structure was revealed to restrain the crystal growth of BiVO4 and ZnO to form nanodots and clusters, respectively. The ternary photocatalyst exhibited excellent xylose conversion (∼90%) to selectively produce formic acid (∼60% selectivity) due to the synergistic effects of light harvesting, mass diffusion, oxygen vacancies and the formed heterojunction structure. The as-fabricated photocatalyst also showed the ability to break down β-1,4-glycosidic linkages of xylan in hemicellulose from wheat straw to produce xylose and formic acid. This work demonstrates a facile pathway for lignocellulose valorization to value-added chemicals by the photorefinery strategy.