LAUSR

Abstract Z-scheme heterojunction photocatalysts often combine the merits of high charge separation efficiency and excellent redox capability. However, ternary g-C3N4 based Z-scheme photocatalytic tandem systems can hardly possess these advantages owing to their low surface area and porosity. We herein report a mesoporous Z-scheme g-C3N4/C/S-g-C3N4 heterostructural nanotube with a high surface area of 450 m2 g−1, synthesized by a nanocasting approach using a highly porous carbon nanorod (CNR) as both the sacrificial template and carbon source. Zinc-trimesic (Zn-BTC) metal organic framework-derived CNR was acidified (denoted as ACNR) before the anchorage of thiourea and dicyandiamide. And the resultant composite (ACNR@TU/DCDA) was subsequently pyrolyzed under mixed N2/air atmosphere, affording g-C3N4/C/S-g-C3N4 heterostructural nanotube in situ. Due to the efficient charge-carrier separation, high redox capability and increased visible light absorption facilitated by the enhanced porous structure, the resultant g-C3N4/C/S-g-C3N4 nanotube proves to be highly efficient for the degradation of methylene blue (MB), rhodamine-B (RhB) and congo red (CR). And the largest reaction factor of 2.37 min−1 g−1 is obtained towards the degradation of MB under visible light irradiation, that remarkably exceeds those over other g-C3N4 based photocatalysts. The concept of in situ fabrication of high surface area g-C3N4/C/S-g-C3N4 heterostructural nanotube revealed in this study will shed light on the synthesis of other ternary Z-scheme photocatalysts with enhanced porous structure and photocatalytic performance.