Photoreduction of Graphene Oxide via Type II Photoinitiators: An Efficient and Environmental Friendly Method for Preparation of Conductive Coating

ABSTRACT Herein, to enhance the universal applicability of the photoreduction of graphene oxide (GO), the capacity of Type II photoinitiators to reduce GO under irradiation of 395 nm LED, along with the underlying photoreduction mechanism are investigated. The results demonstrate that certain photoinitiators, including thiaxanthone and anthraquinone, can effectively reduce GO within 15 min, albeit with varying reduction efficiencies. When 4‐dimethylaminobenzoate (EDB) is employed as a hydrogen donor, isopropylthioanthrone (ITX) exhibits the optimal reduction performance, with the C/O atomic ratio of the reduced sample increasing from 2.11 to 4.83. In addition, a hypothesis regarding the mechanism of GO photoreduction by photoinitiator is proposed, and the occurrence of electron transfer reactions from photoinitiator to GO is verified. For photoinitiators that cannot undergo thermodynamically feasible electron transfer with GO, their actual reduction effect is indeed inferior. Furthermore, RGO/photoresist conductive coatings and patterns with conductivities of 0.17 and 0.78 S cm −1 , respectively, are successfully prepared via in situ polymerization. Notably, the photoinitiator improves the conductivity of the composites through photoinduced in situ reduction of GO to reduced graphene oxide (RGO), indicating that this strategy for preparing graphene composites has wide application prospects in fields such as photocurable coatings.