In situ construction of 1D CdS/2D Nb2CTx MXene Schottky heterojunction for enhanced photocatalytic hydrogen production activity

Abstract Constructing heterojunction photocatalyst with a suitable band energy structure and well-defined interfacial contact is considered to be an effective way for solar-to-hydrogen conversion. CdS with suitable band structure is expected to be an excellent candidate in photocatalytic water splitting to produce hydrogen, but fast recombination of photo-generated carries usually hinders its applications. Nb2CTX, with lower Fermi energy level than Ti3C2TX, has been used as co-catalyst for photocatalysis due to its excellent electroconductivity and hydrophilicity. In this work, a one-step solvothermal method is used to grow in-situ one-dimensional (1D) CdS nanorods on two-dimensional (2D) Nb2CTX under the action of electrostatically driven self-assembly, ensuring the intimate contact at the CdS/Nb2CTX interface to form the 1D/2D Schottky heterojunction. Correspondingly, the CdS/Nb2CTX composite helps to accelerate the separation of electron-hole and charge transfer of CdS, and thus improving its photocatalytic performance. The optimized CdS/Nb2CTX composite (CdS/Nb2CTX-60) presents enhanced photocatalytic activity with hydrogen production rate of 5.3 mmol·g−1·h−1 under visible light, which is 1.7 times higher than that of pristine CdS.