Cd0.5Zn0.5S/Ti3C2 MXene as a Schottky catalyst for highly efficient photocatalytic hydrogen evolution in seawater

Abstract

Abstract Photocatalytic hydrogen evolution is a developing technology that addresses the urgent energy shortage, without greenhouse gas emissions. Despite tremendous efforts over the past decades, the achievement of high-efficiency hydrogen evolution rates for application in semiconductors remains very challenging because of various factors, which include low charge mobility, low light absorption, and high charge carrier recombination. Nowadays, the built-in electric field of metal-semiconductor Schottky junctions exhibits significant developments to overcome the aforementioned limitations because of the enhanced charge separation and transportation efficiency. However, noble metals are scarce and unaffordable to limit the applications. As a promising alternative, the Ti3C2 nanosheets showed excellent metal conductivity which is fascinating. A new Cd0.5Zn0.5S/Ti3C2 composite was fabricated as a non-noble metal-based Schottky junction photocatalyst with enhanced H2 production performance. For a practical exploration, this study expands its application in the realistic environment of natural seawater, which is not only more in line with the sustainable concept but also greatly alleviates the issue of limited freshwater. At present, due to the complex composition of seawater, only a few studies focus on the H2 production of seawater. Remarkably, based on the rational design of the Cd0.5Zn0.5S/Ti3C2 Schottky catalyst, the observed H2 production rate of 9.071 mmol g−1 h−1 is thirty-three times higher than that of traditional Pt assisted photocatalyst in seawater.