Dual channel carrier transfer based on Ti(3)C(2)Tx improves carrier utilization of Z-scheme Ag3PO4/AgBr heterojunction photocatalyst

摘要

With high redox ability of electrons and holes, Z-scheme heterojunction is a promising composite structure in the photocatalysis. However, it is challenging to inhibit the recombination of carriers by Z-scheme transfer. Herein, a novel Ag3PO4/AgBr/Ti(3)C(2)Tx hybrid with dual channel carrier transfer structure was fabricated. Ti(3)C(2)Tx not only serves as a template for growth of Z-scheme Ag3PO4/AgBr, but also can be used to accommodate holes transferred from Ag3PO4 and AgBr. The first channel is consisted of Z-scheme transfer of carriers in Ag3PO4/AgBr. And the hole transfer from the AgBr valence band to Ti(3)C(2)Tx constitutes the second channel, which avoids directly carrier recombination in AgBr valence band. Dual channel carrier transfer pathway was proved by in situ irradiated X-ray photoelectron spectroscopy (ISI-XPS). After Ti(3)C(2)Tx was introduced, the quantum efficiency of Ag3PO4/AgBr increased from 10.59% to 12.50% with reducing Cr(VI), indicating an increase in carrier utilization. The improvement of the degradation efficiency of rhodamine B from 80.77% to 94.72% is benefited from the enhanced quantum efficiency. The dual channel carrier transfer heterojunctions design provides a new idea for constructing an efficient composite photocatalytic structure.