Tuning the heterophase junction in Bi2O3 hybrid crystals with enhanced photocatalytic activity

Abstract

Tuning the crystal structure of Bi₂O₃ crystals from a single β-phase, dual β/γ-phase, and γ-phase can be realized through time-dependent phase evolution through a one-pot hydrothermal method. The β/γ-Bi₂O₃ heterophase hybrids were formed by adequately controlling the crystal growth conditions. The morphology of the dual-phased Bi₂O₃ hybrids presents γ-Bi₂O₃ micro tetrahedra scattered on massive two-dimensional β-Bi₂O₃ triangular nanosheets. In comparison with single β-phase or γ-phase Bi₂O₃ crystals, the β/γ-Bi₂O₃ heterophase hybrids enhance the visible-light absorption capacity, promote the separation of photoinduced carriers, and display minor interfacial resistance. A possible Z-scheme mechanism facilitates photoinduced carrier separation efficiently through the built-in field at the interface. It yields adequate reactive species to stimulate photocatalytic capability towards Rhodamine B degradation. The result herein sheds light on the characteristics of dual-phase Bi₂O₃ crystals and provides an innovative option for the design of self-evolving and highly efficient heterophase photocatalysts.