For the investigation of the effect of pH on the hydrothermal treatment samples were suspended in deionized water (1%, w/v), then the pH was adjusted to 4.0, 5.0, 6.0 and 7.0 with 1 M HCl.
For the investigation of the effect of pH on the hydrothermal treatment samples were suspended in deionized water (1%, w/v), then the pH was adjusted to 4.0, 5.0, 6.0 and 7.0 with 1 M HCl.