Boosting Carrier Separation on a BiOBr/Bi₄O₅Br₂ Direct Z-Scheme Heterojunction for Superior Photocatalytic Nitrogen Fixation

Abstract

Photocatalytic dinitrogen (N 2 ) fixation is regarded as an achievable technology for ammonia (NH 3 ) production. However, the poor separation efficiency of the photoinduced carriers and ineffective N 2 activation remain grand obstacles to high-performance NH 3 photosynthesis. Designing advanced heterostructured systems to accelerate charge separation and activate the N 2 molecule is a feasible strategy to optimize the photocatalytic N 2 fixation activity. Herein, a direct Z-scheme configuration is established between BiOBr and Bi 4 O 5 Br 2 through a facile one-step solvothermal reaction. This configuration enables effective spatial separation of electron−hole pairs and preserves the robust redox ability of carriers, concurrently promoting N�N bond activation and diminishing the energy barrier for the ratedetermining step. The formation of direct Z-scheme BiOBr/Bi 4 O 5 Br 2 heterojunctions is mostly attributed to the similarities in their lattice structures and crystal growth conditions. As a result, the direct Z-scheme BiOBr/Bi 4 O 5 Br 2 heterojunction exhibits a high NH 3 yield of 66.87 μmol g −1 h −1 without using sacrificing reagents, surpassing that of the pristine BiOBr and Bi 4 O 5 Br 2 by approximately 3.3 and 5.6 times, respectively. This study provides an achievable approach to construct direct Z-scheme heterojunction systems for implementing high-performance N 2 fixation under mild conditions.

Schottky Junctions with Bi@Bi2MoO6 Core-Shell Photocatalysts toward High-Efficiency Solar N2-to-Ammonnia Conversion in Aqueous Phase

“…Comparison of photocatalytic N2 reduction activity on Bi-based photocatalysts. References [22,24,36,43,[52][53][54][55][56][57][58][59][60][61][62][63][64][65] are cited in the Supplementary Materials.…”