Large-scale synthesis and enhanced hydrogen storage of monodispersed sulfur-doped carbon microspheres by hydro-sulfur-thermal carbonization of starch

Sulfur-doped carbon microspheres (SCMSs) with large surface area were prepared on large scale by a simple hydro-sulfur-thermal carbonization (HSTC) method using starch as carbon precursor. The morphology and composition of the resulted SCMSs were characterized by scanning emission microscopy, X-ray diffraction, Raman spectrum, and X-ray photoelectron spectroscopy. Experimental results show that monodispersed SCMSs can be obtained by the HSTC of starch under high concentration conditions (up to 1.0 g mL(-1)) by this HSTC method. The as-prepared SCMSs exhibit an enhanced hydrogen storage capacity (3.3 wt% at 77 K and 0.7 MPa) in comparison with the sulfur-free carbon microspheres (0.98 wt%). (C) 2013 Elsevier B.V. All rights reserved.