Construction of morphology-controlled nonmetal 2D/3D homojunction towards enhancing photocatalytic activity and mechanism insight

Constructing homojunction is more favorable to transfer and separation of charge carriers at the interface between structural units owing to the matching chemical and electronic structures, nevertheless it still is difficult to fabricate the morphology-controlled nonmetal homojunction. Herein, a nonmetal 2D/3D homojunction is constructed via the facile surface in-situ polymerization process, where 3D g-C3N4 (3D CC) microspheres tightly anchor on the surface of 2D g-C3N4 (2D CN) nanosheets. The obtained nonmetal 2D/3D CN/CC homojunction displays the dramatically enhanced photocatalytic performance for degrading tetracycline hydrochloride (TC-HCl) compared with single 2D CN nanosheets and 3D CC microspheres, mainly attributing to the improved transfer and separation efficiency of charge carriers resulted from synergetic effect of 2D-3D structural coupling and energy band controlling. Moreover, the important degradation pathway, intermediate products and photocatalytic mechanism are investigated in detail. This work develops a feasible exemplificative strategy for fabricating new morphology-controlled nonmetal homojunction to improve photocatalytic activity. © 2019 Elsevier B.V.