Tailored Ti3C2 MXene/SnS2 nanocomposites to realize both sensitive photoelectrochemical determination and efficient photocatalytic detoxification of Cr(VI)

We proposed a one-pot hydrothermal method for the synthesis of Ti3C2 MXene/SnS2 nanocomposites series and explored the possibility of utilizing them for sensitive photoelectrochemical (PEC) determination of Cr(VI) followed by efficient photocatalytic detoxification. Our research demonstrated that the resultant Ti3C2 MXene/SnS2 nanocomposites with 0.4 wt% of Ti3C2 MXene (labeled as Ti3C2 MXene0.4%/SnS2) possessed the most excellent PEC performance than the monomers (Ti3C2 MXene and SnS2 nanoparticles) and other Ti3C2 MXene/SnS2 nanocomposites with Ti3C2 MXene content of 0.2 wt%, 0.8 wt%, or 1.4 wt%. The developed PEC sensor based on Ti3C2 MXene0.4%/SnS2 nanocomposites showed a good linear response to Cr(VI) in the concentration range of 1.0 pM∼0.1 mM with a low limit of detection of 0.51 pM (S/N = 3). And the Ti3C2 MXene0.4%/SnS2 nanocomposites exhibited the best photocatalytic detoxification efficiency for Cr(VI) after exposure to simulated sunlight for 1 h, reaching as high as 90.2%, whereas 56.9% and 51.7% detoxification efficiency was obtained for pure SnS2 and Ti3C2 MXene, respectively. Our study provides a new material having broad application prospects that are capable of scaled-up for developing online monitoring sensors for Cr(VI) determination as well as the photocatalytic reduction reactor for detoxification of Cr(VI) in various water matrices.