Visible Light-Responsive CeO2/MoS2 Composite for Photocatalytic Hydrogen Production

Abstract

Semiconductor-based photocatalyst materials play an important role in solar hydrogen production. In the present work, we achieved the successful synthesis of a CeO2/MoS2 composite using a facile hydrothermal method. For the preparation of the CeO2/MoS2 composite, the hydrothermal process was carried out at a temperature of 120 degrees C for 24 h, and its performance in hydrogen production was tested. The CeO2/MoS2 composite was characterized using XRD, XPS, Raman spectroscopy, SEM, and optical investigation. The optical study showed that after forming a composite with MoS2, the absorption edge of CeO2 is shifted from the ultraviolet to the visible light region. Bandgap values decreased from 2.93 for CeO2 to 2.34 eV for the CeO2/MoS2 composite. In photocatalytic hydrogen production, Na2SO3-Na2S was used as a sacrificial agent. The CeO2/MoS2 composite exhibited superior photocatalytic hydrogen production performance compared to CeO2 and MoS2. The CeO2/MoS2 composite achieved higher charge separation efficiency, faster charge transfer, more active sites available for redox reactions, and greater affinity towards the reactant ions due to such properties its hydrogen evolution rate has reached 112.5 mu mol/h. The photostability of the CeO2/MoS2 composite was tested in up to four cycles, with each cycle being four hours.