Scaling up the charge transfer on Pd@Ti3C2Tx–TiO2 catalysts: a sustainable approach for H2 generation via water splitting

Abstract

The increasing energy demands have led modern societies to search for green and renewable alternatives that can replace traditional energy sources (i.e. fossil fuels). The aim of this project is to generate sustainable hydrogen from renewable sources. For this purpose, we synthesized highly active MXene-supported catalysts (Pd@Ti₃C₂T_x–TiO₂). In this work, Pd²⁺ ions were directly reduced on Ti₃C₂T_x surfaces without using an additional reducing agent. Morphology and optical characteristics were evaluated using XRD, UV-vis/DRS, SEM, TEM, Raman, and FT-IR techniques. Chemical compositions and surface terminations of the catalysts were examined via EDX and XPS techniques. It was found that low Fermi levels of Pd@Ti₃C₂T_x effectively quench photogenerated electrons and facilitate H₂ evolution without using any sacrificial reagents. This innovative approach enhanced the stability and ability of TiO₂ to effectively transfer the photoinduced charges on the Pd@Ti₃C₂T_x cocatalysts. The role of Pd was elucidated and demonstrated for hydrogen generation progress. The results suggest that the presence of Pd metal over Ti₃C₂T_x surfaces boosted H₂ generation. Overall, Pd@Ti₃C₂T_x–TiO₂ catalysts delivered 35.11 mmol g⁻¹ h⁻¹ of hydrogen. Thus, it was concluded that the as-synthesized catalysts hold promise to replace costly and conventional hydrogen generation technologies.