Accelerating carrier separation to boost the photocatalytic CO 2 reduction performance of ternary heterojunction Ag-Ti 3 C 2 T x /ZnO catalysts.

Developing low-cost and efficient photocatalyst/co-catalyst systems that promote CO 2 reduction remains a challenge. In this work, Ag-Ti 3 C 2 T x composites were made using a self-reduction technique, and unique Ag-Ti 3 C 2 T x /ZnO ternary heterojunction structure photocatalysts were created using an electrostatic self-assembly process. The photocatalyst's close-contact heterogeneous interface increases photogenerated carrier migration efficiency. The combination of Ti 3 C 2 T x and Ag improves the adsorption active sites and reaction centers for ZnO, making it a key site for CO 2 adsorption and activation. The best photocatalysts had CO and CH 4 reduction efficiencies of 11.985 and 0.768 μmol g -1 h -1 , respectively. The CO 2 conversion was 3.35 times better than that of pure ZnO, which demonstrated remarkable stability even after four cycle trials with no sacrificial agent. Furthermore, in situ diffuse reflectance infrared Fourier transform spectroscopy ( in situ DRIFTS) and valence band spectroscopy were utilized to propose the photocatalytic reaction mechanism and electron transfer channels of the Ag-Ti 3 C 2 T x /ZnO system, confirming that CHO* and CO* are the important intermediates in the generation of CH 4 and CO. This study introduces a novel method for the development of new and efficient photocatalysts and reveals that Ti 3 C 2 T x MXene is a viable co-catalyst for applications.