Insight into symmetry matching heterogeneous facet junction photocatalysts via {211} faceted CeO2 nanobelts@δ-Bi2O3 nanowires

Abstract

Photocatalysts with homogenous facet junctions exhibit amazing performance in photocatalytic redox reactions. More challenging and alluring is the construction of heterogeneous facet junctions with two of them. Herein, we show a self-assembly procedure to buildup co-exposing faceted δ-Bi2O3 nanowires on the edges of co-exposing {211} faceted CeO2 nanobelts from sub 10 nm nanoparticles. Directed by surface O-vacancy energy, the δ-Bi2O3 nanoparticles preferentially adsorbed on the {111} facets of CeO2 nanobelts and oriented growth into co-exposing faceted δ-Bi2O3 nanowires. The CeO2@δ-Bi2O3 hetero facet junction displays superior and stable hydrogen evolution activities, 5.2 times of the pure co-exposing faceted CeO2 nanobelts, ascribed to following key factors: First, heterogeneous facet junctions contribute to efficient interplanar and inter-junction separation of photocarriers. Moreover, symmetry matching leads to strong connection between the two facet junctions, facilitating the dynamic charge transfer. This work can provide a new strategy in the design of heterojunction photocatalytic systems for water splitting.