Adsorption‐Induced In‐Situ Construction of TiO<sub>2</sub> Hollow Sphere/UiO‐66‐NH<sub>2</sub> Heterostructures with Boosted Photocatalytic Activity toward Cr(VI) Reduction
Qiankun Xu, Yaru Li, Wen Ji, Jun Mei, Xianbiao Wang
Abstract
Abstract Water contamination caused by highly toxic Cr(VI) should be resolved imminently with a more efficient photocatalytic approach. The interaction between photocatalyst heterostructure is critical for charge separation which largely affects the photocatalytic efficiency. Herein, TiO 2 hollow sphere/UiO‐66‐NH 2 (TiO 2 /UiO‐66‐NH 2 ) heterostructures were successfully synthesized by an adsorption‐induced in‐situ solvothermal growth strategy. The UiO‐66‐NH 2 particles were well dispersed on TiO 2 hollow spheres by solvothermal treatment of Zr 4+ adsorbed TiO 2 hollow spheres with NH 2 ‐BDC ligand. The photocatalytic activities of TiO 2 /UiO‐66‐NH 2 heterostructures were investigated by reduction of Cr(VI) with visible light irradiation. With the introduction of UiO‐66‐NH 2 , the reduction efficiency toward Cr(VI) by TiO 2 /UiO‐66‐NH 2 heterostructures reached 89% after 180 min of irradiation, which is much higher than those of TiO 2 hollow spheres (10%) and UiO‐66‐NH 2 crystals (29%). Moreover, the TiO 2 /UiO‐66‐NH 2 heterostructures display good regeneration ability and can still maintain 70% of Cr(VI) removal ability after four cycles. The integration of TiO 2 and UiO‐66‐NH 2 could construct a type‐II heterojunction to broaden the absorption range of light and suppress the recombination of photoproduced electrons and holes. As a result, such unique composite structure significantly enhance the photocatalytic performance towards Cr(VI) reduction. This work not only inspires a new approach for in‐situ solvothermal synthesis of semiconductor@MOFs composites, but provides a novel photocatalyst for highly efficient removal of Cr(VI) from wastewater.