. 2017 Jun 4;134:74–89. doi: 10.1016/j.energy.2017.06.010
© 2017 Elsevier Ltd
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited.
Figure 1.
SEM micrograph of unprocessed HF