Preparation of Mo2CTx MXene as co-catalyst for H2 production by etching of pure/mixed HBr solution

Mo 2 C T x is a novel co-catalyst to enhance the photocatalytic performance of CdS for H 2 production. The surface of Mo 2 C T x is usually terminated by fluorine anion because it is generally made by the etching of fluoride-containing solution. Here we report, a novel method to prepare highly pure MXene with Br termination by the etching of pure HBr at 220 °C for 3 d, or the HBr solution mixed with LiBr, NaBr, KBr or NH 4 Br at 180 °C for 24 h. The pure HBr etching needs higher temperature and longer time to make pure Mo 2 C T x , however, which result lager interlayer space and more active sites. All the Mo 2 C T x samples show high co-catalytic performance to enhance the photocatalytic performance of CdS for H 2 production. The H 2 production rate of CdS combined with HBr etched sample was 17,566 μmol g −1  h −1 , similar with the sampled combined with traditionally HF etched sample. This is the first report to prepare MXene by etching of Br containing solution. The Mo 2 C T x made by this method is terminated by Br/O without F, and show excellent co-catalytic properties.