Boosting charge spatial separation efficiency for catalytic H2 bubble evolution under macroscopic spontaneous polarization electric field

Abstract

Serious recombination of photo-irradiated electrons ( e − ) and holes ( h + ) over photocatalysts restricts solar energy conversion, and directional transfer of e − / h + to reduction/oxidation locations respectively and simultaneously, is enormously difficult under the shackle of Coulomb field. Herein, internal spontaneous polarization electric field (ISPEF) has been constructed by coordination between 4 d 10 orbit of Cd 2+ and sp 2 -hybridized N to induce a non-overlapping state of two opposite charge centers in g -C 3 N 4 , which could thus boost charge spatial division and migration. The significantly improved efficiency for H 2 evolution, accompanying by consecutive emission of visual H 2 bubbles was realized. Photo-irradiated charge spatial separation and photocatalytic mechanism within ISPEF of CdC 3 N 4 was firstly confirmed by theory prediction and Hall effect characterization. The study strategy supplies a novel perspective to design polarized semiconductor materials for significantly effective solar energy transformation, which will bring about another research highlights for constructing efficiently advanced semiconductor materials. • Internal spontaneous polarization electric field (ISPEF) was constructed in g -C 3 N 4 . • Strong ISPEF boosts charge spatial separation and directional transfer effectively. • g -C 3 N 4 was polarized by coupling Cd 2+ 4 d 10 orbit with its sp 2 -hybridized N. • Visual H 2 bubbles were released over photocatalysts within ISPEF. • Theoretical calculation and Hall effect test were adopted to confirm ISPEF action.