Bismuth Oxide Based Array Structures:Fabrication And Applications In Photoelectrochemical Water Splitting

The goal of this dissertation is to explore the controllable fabrication of bismuth oxide based array structures with favorable morphologies by understanding the crystal structural characteristics of the target products and developing novel chemical reaction routes. On the basis of the unique morphology and various chemical modifications, application of these bismuth oxide based array structures has been further developed as active anode materials for photoelectrochemical water splitting, and the corresponding morphology-property relationships have been also investigated in this dissertation. The details are summarized briefly as follows:1. We successfully fabricated vertically aligned BiVO4nanowall array supported on ITO glass through a facile hydrothermal method. The growth of BiVO4nanowall began with heteroepitaxy and underwent a ripening process to form an extended network, resulting in c-orientation and exposing (010) facets. The integrated photoelectrodes showed superior photoelectrochemical performances under visibe light, indicating the importance of rationally designed physical models for photoelectrodes.2. We developed an available pathway to accomplish the fabrication of BiVO4nanowall arrays decorated with surface-attached catalysts (Co-Pi). Co-Pi/BiVO4nanowall arrays were introduced as active anode materials for photoelectrochemical water splitting. Quantitative assessment on independent effects of heteroepitaxy and surface modification for suppressing bulk and surface recombination further elucidate the mechanism of the superior absorbed photon-to-electron conversion efficiency. Applying the synergistic effects of growth adjustment and surface modification into other candidate photoelectrodes exhibits a promising avenue to realize ameliorated solar conversion efficiency.3. In order to ease the problems of light harvesting in nanowall arrays, we introduced alternate dielectric component into nanowall skeleton. Their photoelectrochemical performances were investigated as anode materials for solar water splitting. This rational design further expands the application of nanowall arrays in this research area.4. We introduced a controllable colloidal crystal template method to realize the design of three-dimensional ordered macro-mesoporous Mo:BiV04for the first time. All the observed photoelectrochemical performances highlight the great significance of such an array as a promising photoelectrode model for application in solar conversion and the synergistic improvements of chemical modification and a purpose-designed photoelectrode structure.