Hierarchical hole-enhanced 3D graphene assembly for highly efficient capacitive deionization

A hole-rich graphene framework (HGF) has been successfully prepared through lyophilization combined with thermal treatment at 200 °C. As the advanced three-dimensional (3D) graphene mesh assembly, the monolithic HGF was directly compacted to form capacitive deionization (CDI) electrode without grinding and binder so that the intact 3D structure can be reserved. The presence of original 3D structure combined with hierarchical hole structure in HGF plays important role in improving the CDI performance. The desalination capacities of HGF can reach up to 8.0 mg g−1, 16.9 mg g−1, and 29.6 mg g−1 in NaCl aqueous of 80 mg L−1, 270 mg L−1, and 572 mg L−1 respectively, which significantly exceeds other carbon-based materials at 2.0 V.