“…This type of nanocomposites can be obtained by directly intercalating nanomaterials within the interlayer space of clay minerals (Gournis et al, 2004(Gournis et al, , 2006Tsoufis et al, 2013), or by in-situ transforming the pre-intercalated materials into nanomaterials (Ma et al, 2013;Ruiz-Hitzky et al, 2011;Xu et al, 2013;Zhang et al, 2012). Generally, the direct intercalation method is only applicable for very small nanomaterials, e.g., fullerene and its derivatives (Gournis et al, 2004, Applied Clay Science 100 (2014 2006; Tsoufis et al, 2013). As such, the in-situ transformation method draws more attention (Fernandez-saavedra et al, 2008;Ruiz-Hitzky et al, 2011;Xu et al, 2013;Zhang et al, 2012).…”