Rod-Like BiVO ₄ –Bi ₂ O ₂ CO ₃ Nanosheet Composites as Photocatalysts for Hydrogen Generation

High Resolution Image Download MS PowerPoint Slide BiVO 4 /Bi 2 O 2 CO 3 photocatalysts were prepared by a hydrothermal method in the presence of deep eutectic solvent (DES). The relationship between synthesis conditions and the formation of distinct crystal phases was systematically investigated, providing insights into the role of DES in tuning phase, morphology, and H 2 generation performance of BiVO 4 -based photocatalysts. Without DES, BiVO 4 nanomaterials with mixed crystal phases and different morphologies were obtained at different pH levels. After DES was introduced, rod-like monoclinic scheelite BiVO 4 /Bi 2 O 2 CO 3 composite photocatalysts consisting of self-assembled nanosheets were obtained, regardless of whether the solution was acidic, neutral, or basic. DES acts as the carbon source of Bi 2 O 2 CO 3, the crystal phase/morphology-control agent, and the solvent. Adding DES results in the formation of BiVO 4 /Bi 2 O 2 CO 3 heterostructures, ms-BiVO 4 phase, oxygen vacancies, and type II band structures, leading to increased carrier separation efficiency and enhanced H 2 production performance of the photocatalyst. The optimized BiVO 4 /Bi 2 O 2 CO 3 composite photocatalyst (D2P2BVO4) exhibits an H 2 generation activity of 8783 μmol h –1 g –1, which is 1.5 times that of the BiVO 4 photocatalyst (P7BVO).