Related Experiment Video
Updated: Oct 15, 2025
Chemical Synthesis of Porous Barium Titanate Thin Film and Thermal Stabilization of Ferroelectric Phase by Porosity-Induced Strain
Published on: March 27, 2018
Enhanced Catalytic Mechanism of Twin-Structured BiVO4
Meirong Huang1, Wanzhen He2, Zhiping Xu2
1State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China.
Abstract:
Twin engineering is an efficient strategy to improve the photocatalytic activity of semiconductors (e.g., BiVO4). A systematic study that combines theory and experiments is conducted to reveal the underlying enhanced catalytic mechanism of twin-structured BiVO4. The key characteristic of twinned structures is the partial strain introduced by twin boundaries. Lattice distortion introduced by the twin boundaries leads to charge redistribution and built-in electronic fields between the twin boundaries and the bulk. The generated homojunctions possess a staggered band alignment structure, and their band offsets are increased by the Fermi-level pinning effect. The series of homojunctions in twinned structures is beneficial for facilitating charge separation. Additionally, lattice distortion around twin boundaries leads to the broken geometric symmetry of metal-oxygen polyhedrons in twinned crystals. The adsorption energies of adsorbates decrease significantly, resulting in reduction of the overpotential. The reduced overpotential favors acceleration of the oxygen evolution reaction on twinned structures.
More Related Videos
Related Concept Videos
02:42Valence Bond Theory
02:46Crystal Field Theory - Tetrahedral and Square Planar Complexes
Crystal field theory (CFT) is applicable to molecules in geometries other than octahedral. In octahedral complexes, the lobes of the dx2−y2 and dz2 orbitals point directly at the ligands. For tetrahedral complexes, the d orbitals remain in place, but with only four ligands located between the axes. None of the orbitals points directly at the tetrahedral ligands. However, the dx2−y2 and dz2 orbitals (along the Cartesian axes) overlap with the ligands less than the dxy,...
02:58Crystal Field Theory - Octahedral Complexes
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
03:24Hybridization of Atomic Orbitals I
04:01VSEPR Theory and the Effect of Lone Pairs
02:42Ionic Crystal Structures
Most monatomic ions behave as charged spheres, and their attraction for ions of opposite charge is the same in every direction. Consequently, stable structures for ionic compounds result (1) when ions of one charge are surrounded by as many ions as possible of the opposite...