Sustainable and high-quality synthesis of carbon nanospheres with excellent dispersibility via synergistic external pressure- and PSSMA-assisted hydrothermal carbonization

Strict control of the monodispersity and size of hydrothermal carbon nanospheres (CNSs) with a size less than 150 nm is a prerequisite for many applications. However, designing and achieving the mass production of high-quality glucose-derived CNSs have been very challenging. Herein, we successfully synthesize PCNSs-PSSMA through a simple method that is synergistically assisted by an external pressure (2.0 MPa) and a small amount of poly(4-styrenesulfonic acid-co-maleic acid) sodium salt (PSSMA). The mechanism of the external pressure and PSSMA effect on the synthesis of PCNSs-PSSMA is investigated. On the one hand, the pressure and PSSMA can increase the glucose hydrothermal carbonation (HTC) rate and increase the number of carbon nuclei. On the other hand, PSSMA adsorbs on the surface of the CNSs to inhibit their growth so that more raw materials can be used for nucleation. When limited by the raw materials, it is difficult for CNSs to continue to grow. Furthermore, we also verify that PCNSs-PSSMA is superior in terms of adsorption and catalysis to large carbon spheres prepared by traditional methods. Our findings provide potential guidance for the mass production of other small particle size nanomaterials.