Synthesis and photocatalytic H2-production activity of plasma-treated Ti3C2Tx MXene modified graphitic carbon nitride

Plasma processing technology, as a promising method to enhance photocatalytic activity of catalyst, is gradually attracting extensive interest from researchers. However, the main mechanism of plasma-treated photocatalyst on hydrogen production is not clear. In this work, 2D Ti3C2Tx MXene is selected as a co-catalyst of graphitic carbon nitride (g-C3N4), which carries out a plasma treatment (500 degrees C) under N-2/H-2 atmosphere. Due to plasma treatment, there is a higher proportion Ti-O functional groups on surface of layered Ti3C2Tx MXene, especially for Ti4+. The obtained g-C3N4/p-Ti3C2Tx photocatalyst with sandwich-like structure shows an enhanced photocatalytic activity. The rate of hydrogen generation of CN/pTC3.0 sample without Pt co-catalyst is 25.4 and 2.4 times that of pure g-C3N4 and CN/TC3.0 samples, respectively. The improved photocatalytic activity is attributed to presence of Ti4+ due to plasma treatment, which can capture photo-induced electron from g-C3N4 and improve the separation of electrons and holes after visible light irradiation. The cyclic hydrogen production of the photocatalyst demonstrates good photocatalytic stability. In addition, this method of plasma treatment under N-2/H-2 atmosphere is feasible to develop a high-performance co-catalyst, which can be extended to other photocatalysts with two-dimensional structure for photocatalytic water-splitting applications.