After each experiment, the suspensions were centrifuged, washed with pure acetone and dried under vacuum at 85 • C for 24 hours. Samples were gold coated and imaged on a Carl Zeiss 300VP scanning electron microscope (SEM). X-ray diffraction (XRD) data were obtained from a PANalytical Empyrean diffractometer using Cu-K α radiation. The 2θ scan range, step size and K α 1 /K α 2 are 10 to 80 • , 0.013 • and 0.5, respectively. At ambient temperature (∼25 • C), a Micromeritics Gemini V Surface Area Analyzer was used to assess the particle specific surface area (SSA) with Brunauer-Emmett-Teller (BET) method using N 2(g) . The degassing was conducted at 105 • C.