Front Cover: In article number 2200149 by Weijun Zhen and co-workers, graphene quantum dots (GQDs) are prepared by a low-cost, convenient, and environmentally friendly strategy with brown-black humic acid (BBHA) as a raw material. Then, polyphenylene sulfide (PPS)/GQDs nanocomposites are prepared. GQDs can affect the mechanical properties, crystallization, and rheology of PPS. Simultaneous spectroscopic and rheological characterization of PPS/GQDs nanocomposites are also studied, which may provide a new method to study the crystallization of PPS. In this cover, a part of the schematic diagram of GQDs preparation process is included, and the infrared spectrum during crystallization is also shown.