Confined synthesis of BiVO4 nanodot and ZnO cluster co-decorated 3DOM TiO2 for formic acid production from the xylan-based hemicellulose photorefinery

Abstract

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.