Ligand functionalization on Zr-MOFs enables efficient visible-light-driven H2O2 evolution in pure water

Abstract

Different ligand functionalized UiO-66 (UiO-66-X, X = OH, (OH)₂ and NH₂) were prepared and then modified by ZnIn₂S₄ lamellas to form ZnIn₂S₄/UiO-66-X heterostructures for visible-light-driven H₂O₂ evolution in pure water. The H₂O₂ yields using ZnIn₂S₄/UiO-66-NH₂, ZnIn₂S₄/UiO-66-(OH)₂ and ZnIn₂S₄/UiO-66-OH are 799, 733 and 165 μmol L⁻¹, respectively, which are 9.5, 8.7 and 2.0 times that of ZnIn₂S₄/UiO-66. The high performance of ZnIn₂S₄/UiO-66-NH₂ and ZnIn₂S₄/UiO-66-(OH)₂ is ascribed to the benign visible-light response and Z-scheme heterostructures, and the H₂O₂ evolution abides by indirect O₂ reduction with ˙O₂⁻ as an intermediate species. Additionally, H₂O₂ yields using ZnIn₂S₄/UiO-66-NH₂ on tap water and Xuanwu Lake (Nanjing, China) water can be comparable to that on the above-deionized water. This study sheds light on the great promise of functionalized MOFs and their applications on green (photo)catalytic energy conversion.