Facile one-step hydrothermal synthesis of single-crystalline SnNb 2 O 6 nanosheets with greatly extended visible-light response for enhanced photocatalytic performance and mechanism insight

Abstract The conventional preparation of SnNb 2 O 6 invariably involves complex and laborious steps, which unavoidably introduces defect into the host lattice and also increases the reaction period and costs, resulting in undesired recombination of photo-generated electron–hole pairs. For the first time in this work, we manage to synthesize single-crystalline two-dimensional (2D) SnNb 2 O 6 nanosheets with ultrathin structure through a facile one-step hydrothermal method. Comparative studies were explored to analyze the structure and phase evolution during the preparation course. The synthesized 2D structure demonstrated a narrower band gap of 2.09 eV and specific surface area of 76.1 m 2 g −1 , which exhibited significantly extended visible-light-responsive range and larger surface area by contrast with the state-of-the-art reports, resulting in excellent visible-light-driven photoactivity towards H 2 production and water purification as well. Additionally, further enhanced photocatalytic performance was achieved by the incorporation of Pt as co-catalyst to indirectly indicate the advantage of the SnNb 2 O 6 nanosheets in this method over other reported counterparts. It was found that, a very small amount of Pt loaded on the surface of SnNb 2 O 6 nanosheets would contribute to remarkably higher activity than pure SnNb 2 O 6 nanosheets and exhibit superior stability as well. Moreover, a deep insight into the underlying photocatalytic mechanism was proposed. This work sheds light on a new facile way to fabricate high-performance photocatalytic materials and provided new opportunities for solar-energy conversion.