Carbon dots (CDs) are a kind of zero‐dimensional carbon‐based nanoparticles with superb light‐trapping ability, high optical absorption ability, and superior intrinsic catalytic activity. Due to these advantageous properties, they have received enthusiastic attention from researchers in the field of optical devices. The application of carbon dots in dye‐sensitized solar cells has increased with steady steps recently, especially as a substitute for precious Ru‐sensitizers and Pt counter electrodes. In this review, we classified the application of carbon dots in dye‐sensitized solar cells in recent years and explained the mechanisms of improving the performance of carbon dots. The significant impact of surface functionalization of CDs on the performance of dye‐sensitized solar cells was discussed. Lastly, some challenges and application prospects of carbon dots in the dye‐sensitized solar cell were proposed, which is meaningful for the further exploration and application of carbon dots as a new energy material. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48443.

3D printing technology is a versatile technology. The waste of 3D printed plastic products is a matter of concern because of its impact on the circular economy. In this paper, we discuss the current status and problems of 3D printing, different methods of 3D printing, and applications of 3D printing. This paper focuses on the recycling and degradation of different 3D printing materials. The degradation, although it can be done without pollution, has restrictions on the type of material and time. Degradation using ionic liquids can yield pure monomers but is only applicable to esters. The reprocessing recycling methods can re-utilize the excellent properties of 3D printed materials many times but are limited by the number of repetitions of 3D printed materials. Although each has its drawbacks, the great potential of the recycling of 3D printed waste plastics is successfully demonstrated with examples. Various recycling approaches provide the additional possibility of utilizing 3D printing waste to achieve more efficient circular application.