Mixed 1T-2H phase MoSe2 as interfacial charge-transfer-bridge to boosting photocatalytic activity of dual Z-scheme AgI/1T-2H MoSe2/Bi4O5Br2 heterojunction

The transition metal dichalcogenides (TMDs) with 1T phase structure holds great promise for providing abundant active sites and superior conductivity, while the achievement of highly efficient degradation activity over bare TMDs and TMDs-based photocatalysts is still challenges. In this work, a flower-like mixed 1T-2H phase MoSe2 was synthesized via a sodium borohydride (NaBH4)-assisted solvothermal method, and then was selected as a "charge-transfer-bridge" to fabricate a dual Z-scheme AgI/1T-2H MoSe2/Bi4O5Br2 composite with a 0D/3D hierarchical structure. The optimal AgI/1T-2H MoSe2/Bi4O5Br2 composite exhibited the superior photocatalytic activity towards degrading RhB and TC relative to AgI/2H MoSe2/Bi4O5Br2 and AgI/Bi4O5Br2. The enhancement is attributed to its better light absorption, abundant active sites, and superior charge carrier mobility and separation efficiency, resulted from synergetic effect of 0D/3D structural coupling and energy band matching. Moreover, the important energy band alignments and mixed 1T-2H phase MoSe2 boosting photocatalytic mechanism of as-prepared AgI/1T-2H MoSe2/Bi4O5Br2 heterojunction were investigated. This work describes a competitive design and fabrication technique for constructing novel mixed phase TMDs-based Z-scheme heterojunctions to address environmental issues. (C) 2021 Elsevier B.V. All rights reserved.