Synergetic excitonic and defective effects in confined SnO2/α-Fe2O3 nanoheterojunctions for efficient photocatalytic molecular oxygen activation

Abstract

The research with respect to the excitonic effect now predominantly focuses on the organic semiconductors, while the case taking place in the inorganic semiconductors is rarely discussed. Here, cone and hyacinthus orientalis-like SnO2/α-Fe2O3 nanoheterojunctions were obtained via a simplistic hydrothermal synthesis followed by a annealing process, which respectively showed unique spherical hollow structure and 2D hierarchical nanosheets on their surface. Abundant oxygen vacancies confined in lattice of nanoheterojunctions were introduced, which facilitated the exchange of ambiance oxygen and lattice oxygen. Systematic examinations revealed that the optimized nanoheterojunctions and rich oxygen vacancies led to superior visible-light photocatalytic activity in the activation of active molecular oxygen, including H2O2 production. This work brightens excitonic and defective aspects for the chemical interface design in bulk heterojunction materials to produce reactive oxygen species with high photocatalytic activity, and provide guidance for the construction of efficient heterostructures and extend their potentials to other fields.