Constructing defect engineered 2D/2D MoO3/g-C3N4 Z-scheme heterojunction for enhanced photocatalytic activity

Photocatalytic redox technology is established in energy and environmental governance with its en-vironmentally friendly and broad-based optical source. However, the development of photocatalysts with strong redox ability still remains urgently desirable. Herein, an oxygen vacancy-engineered 2D/2D Z-scheme hetero-junction photocatalytic materials of MoO3/g-C(3)N(4 )are synthesized, which achieves a trade-off between the value band position of MoO3 with high oxidation property and the conduction band position of g-C(3)N(4 )with high reduction property. The 2D/2D heterojunction manifests excellent functionality for photocatalytic H-2 evolution and tetracycline degradation. Particularly, 3 % MoO3/g-C3N4 provides the optimum H-2 generation rate (328.75 mu mol g(-1) h(-1)) without any noble metal cocatalyst, which is about 87-fold higher than that of pure g-C3N4 (3.78 mu mol g(-1) h(-1)). Moreover, the TC degradation kinetic constant of 3 % MoO3/g-C3N4 (0.0196 min(-1)) is about 8.28 times of pure g-C3N4 (0.0023 min(-1)). The outstanding photo-catalytic ability mainly comes from the interfacial interaction between 2D MoO3 and 2D g-C3N4, which can shorten the transport distance of charge carriers and contribute abundant active sites to improve the separation efficiency of photogenerated carriers. Furthermore, the oxygen vacancies (OVs) strengthen the redox potential of the system and serve as effective trapping sites for photogenerated carriers to reduce the quenching rate of photogenerated electrons. This work provides a feasible strategy to develop 2D/2D Z-scheme photocatalytic systems with high photocatalytic performance on energy storage and environmental application. (C) 2022 Elsevier B.V. All rights reserved.

Automated summary

By engineering oxygen vacancies, a 2D/2D heterojunction photocatalytic material of MoO3/g-C(3)N(4) is synthesized and shows excellent performance in H-2 evolution and tetracycline degradation. The high photocatalytic ability of this material mainly comes from the interfacial interaction, efficient charge separation, and strengthened redox potential due to oxygen vacancies.